November 8 – 11th, 2012
If there is a problem with your abstract, please contact the Secretariat ASAP, and we’ll make sure it gets fixed. All abstracts are sorted by first author.
THE USE AND MISUSE OF ECOLOGICAL THEORY IN CORAL REEF MANAGEMENT
The University of North Carolina at Chapel Hill
There is no question that coral reefs have changed immensely over the last several decades. Reef-building corals are being replaced by seaweed, sponges and gorgonians, and big fish are being replaced by very little fish. But what can be done to reverse these trends? Ecology has come to the rescue with theoretical concepts like “resilience” and “alternative stable states”. Many ecologists have argued that by applying these ideas to coral reef restoration and management, we can reverse reef degradation and mitigate the impacts of global climate change. The logical solution, they argue, is to create MPAs that will restore “reef resilience” via enhanced herbivory. Although widely promoted, these conceptual ideas are rarely tested with empirical evidence. The reality is that seemingly promising solutions, like the creation of marine reserves, are doing little to mitigate the primary threats to coral reefs, particularly the looming impacts of ocean warming and acidification. Even basic patterns that should underlie the application of ecological concepts to coral reef management are difficult to find in nature. An approach based firmly on real-world spatiotemporal patterns, with less reliance on theory might be a more effective way for ecologists to contribute to marine conservation.
Gerber, L. *
INTEGRATING DATA AND THEORY IN THE GLOBAL MANAGEMENT OF WHALES
Arizona State University
Whether and how many whales should be hunted are questions of tremendous global significance. The International Whaling Commission (IWC), charged with the global conservation and sustainable use of whales, introduced a moratorium on commercial whaling in 1986. The moratorium, however, did not eliminate whaling. Today, scientific whaling (~1,000 whales/yr), whaling under objection to the IWC (~590 whales/yr), and subsistence whaling (~350 whales/yr) continue. The persistence of largely unregulated whaling has sparked heated debates at IWC meetings about resuming formally sanctioned whaling. The failure of decades of negotiations between pro- and anti-whaling nations has called into question the future of the IWC as a management entity. Resolution is complicated by diverse management and ethical issues. I highlight the use of ecological theory and data in developing practical solutions for three important key management challenges: whale sanctuaries, interactions with fisheries, and conservation markets. Examples of non-trivial ethical debates being resolved through international agreements are rare in practice, which underscores the need for alternative solutions that rely on both data and theory.
FORECASTING BIOLOGICAL INVASIONS USING DATA LIMITED MODELS
Some exotic species cause substantial economic and environmental impacts, yet most are innocuous. Forecasting risks from exotic species will help prioritize management. Unfortunately, we rarely have direct measures of the different components underlying biological invasions (TEASI – Transport, Establishment, Abundance, Spread, Impact). More generally, in invasion biology and most of conservation biology, we are challenged by limited information, limited resources and limited time. As such, to be relevant for policy and provide advice in a timely manner, we must make predictions using accessible data. I will focus on predictive ecology, presenting approaches and results for forecasting invasions, given inherent uncertainty that arguably occur within all fields in ecology and the environmental sciences.
Munch, S.B. *
TOWARDS MODEL-FREE ECOSYSTEM MANAGEMENT
Southwest Fisheries Science Center, NOAA, University of California, Santa Cruz
There are many good reasons for ecosystem-based approaches to management. In particular, ecosystem approaches to management promise to make explicit the trade-offs between yields at different trophic levels and help avoid the systemic problems engendered by single-species management. Numerous ecosystem models have been developed to help quantify these trade-offs. There is, however, a great gulf between ecosystem models and ecological reality. Real ecosystems have more species, more life-stages within species, and more phenotypic diversity within life-stages than any model can hope to address: every ecosystem model contains numerous `simplifying’ assumptions that are simultaneously unlikely to be true and potentially critical to model predictions.
In light of this, the key to successful ecosystem-based management may be to relax these assumptions and make robust, short -term ecosystem forecasts that don’t rely on an explicit model structure. To this end, we have developed tools for non-parametric Bayesian analysis of population dynamics. These nonparametric methods significantly outperform parametric models at multispecies forecasting for both simulated data and field observations. Current research in this area is focused on scaling-up these nonparametric methods to ecosystem-wide forecasts, ecosystem-level risk assessment, and multi-species management strategy evaluation.
Salomon, Anne *
MERGING DATA AND THEORY IN KELP FOREST ECOSYSTEMS; ILLUMINATING NATURE’S DYNAMIC
Simon Fraser University
Fertile ground lies at the intersection of empiricism and theory. Using empirical data from Californian kelp forests, I show how fitting simple theoretical models of species interactions to experimentally-derived estimates of trophic rates can reveal the nonlinear dynamics responsible for alternative states and illuminate the role of predator functional redundancy in enhancing the resilience of kelp forests to trophic cascades. We have also begun combining monitoring and isotopic data from British Columbian kelp forests with theory on species niches and metabolic scaling to inform historical baselines and assess current and future effects of fishing on food web dynamics. Fitting process-based models to empirical data is a fruitful way to unify empiricism and theory, resolve long standing debates in ecology, improve our predictive abilities and thereby better inform our understanding of alternative conservation policies and their potential ecosystem outcomes.
Duffy, J.E. *
BIOCOMPLEXITY AND CONTROL OF VEGETATED MARINE ECOSYSTEMS: FROM BUCKETS TO THE BIOSPHERE
Virginia Institute of Marine Science
Community and ecosystem processes are mediated by interactions between resource supply, consumer pressure, and community composition, with the balance shifting along environmental gradients. A frontier in basic and applied ecology is understanding how these processes interact and organizing the complexity into predictive models. Our collaborative research seeks to address this challenge in seagrass beds, which are important but threatened habitats in coastal seas worldwide. By integrating parallel manipulative experiments in mesocosms (“buckets”) and field with comparative and observational studies across large scales (“biosphere”), we are quantifying how changing resource supply interacts with changing species composition to affect production, trophic transfer, and habitat creation along gradients of environmental and human influence. Our studies focus on herbivory as a key link mediating both bottom-up and top-down processes in vegetated marine systems. An emerging picture shows that the species composition, and by extension the functional trait composition, of both plants and herbivores fundamentally influences the structure and functioning of coastal ecosystems and their ability to provide important ecosystem services to humanity.
Helmuth, B. *
ONE RESEARCHER’S REDUCTIONISM IS ANOTHER’S GENERALIZATION: WHEN DO “THE DETAILS” MATTER?
University of South Carolina
Recent years have witnessed an explosion in calls from funding agencies for interdisciplinary research, and for the training of students and researchers in ways that span traditional disciplinary boundaries. While most scientists recognize the importance of “thinking outside the box” what does such an approach truly entail? The testing of models in biology and physics entails measurements of model skill- the effectiveness of the model to predict key response variables. Using examples from my own work as well as that of others I will discuss how testing model skill using metrics developed by from other disciplines (end users) can reveal shortcomings in how we design physiological and ecological studies. Specifically, I will discuss how the scale of physical data can have significant consequences for predictions of physiological performance, and how physiological details in turn translate into ecological, biogeographic and socioeconomic consequences. These results argue that in order to perform true interdisciplinary research, our experiments and models must be designed at the onset based on their subsequent application, and that a “loading dock” approach whereby data and model projections are simply provided to a downstream collaborator or end user is likely to fail.
Koehl, M.A.R. *
HOW DO WATER-BORNE LARVAE OF BENTHIC ANIMALS LAND IN THE RIGHT PLACE?
University of California, Berkeley
Many benthic marine animals produce microscopic larvae that are dispersed to new sites by ambient water currents. Where those larvae recruit into benthic habitats is ecologically important because it affects local community structure and larger scale meta-population dynamics. We have been studying how these larvae manage to land in suitable habitats. Our interdisciplinary project (biology, ecology, engineering, math) involves field and laboratory studies of how dissolved chemical cues released by organisms on the substratum are dispersed in turbulent wave-driven water flow, and how small weakly-swimming larvae can respond to those odors in ways that affect where they land and can stay put while being buffeted by flowing water. We measured flow in the field and recreated it in flumes where we could quantify on the scale experienced by larvae (mm’s, ms’s) the instantaneous water velocities and concentrations of odors released from surfaces where larvae settle. These data enabled us to design small-scale experiments in which larval behavior was analyzed in realistic, rapidly varying patterns of water flow and odor. We have used these data about organismal-level mechanism in models of larval settlement to explore the consequences of different larval behaviors and properties in various types of flow habitats.
Sanford, E. *
INTERDISCIPLINARY STUDIES OF OCEAN ACIDIFICATION IN A COASTAL UPWELLING ECOSYSTEM
Bodega Marine Laboratory, University of California Davis
Increasing atmospheric carbon dioxide is altering the chemistry of the oceans and poses a growing threat to marine ecosystems. To address this complex problem, we have formed a consortium of West Coast ecologists, evolutionary biologists, physiologists, and oceanographers called the Ocean Margin Ecosystems Group for Acidification Studies (OMEGAS). Using a network of intertidal and moored sensors, we have documented a coastal mosaic of pH across our four study regions, ranging from southern California to central Oregon. Within this oceanographic context, we are testing the response of purple sea urchins (Strongylocentrotus purpuratus) and other ecologically important species to ocean acidification. We cultured sea urchin larvae from each region under control and elevated seawater pCO2, and simultaneously examined growth of skeletal rods, the timing of development, and genetic change at >19,000 loci. For all populations, larval morphology and development showed only minor responses to elevated pCO2. However, we found substantial allelic change in 40 functional classes of proteins, suggesting natural selection for larvae with specific alleles. Our sensor data indicate that urchin larvae may be exposed frequently to high pCO2 during upwelling events. This oceanographic setting likely maintains standing genetic variation which might provide urchin populations some resilience to future climate change.
White, J.W. *
INTEGRATING THEORY AND DATA IN MARINE ECOLOGY, OR: HOW I LEARNED TO STOP WORRYING AND LOVE THE CALCULUS
University of North Carolina, Wilmington
Ecology is fundamentally a mathematical discipline. Ecologists use mathematical theories to describe the physical laws governing complex processes and to distinguish signals in noisy datasets. However, ecologists must be aware of the limitations of their mathematical toolbox: if all you have is a hammer (e.g., ANOVA), everything looks like a nail (e.g., a balanced, replicated experiment with categorical treatments). Often, ecological datasets are not amenable to standard analytical techniques. I describe the approaches my colleagues and I have taken to develop new theoretical tools to address ecological problems, using three case studies: density-dependent mortality in coral reef fish, top-down and bottom-up controls on oyster populations in a California estuary, and fish population dynamics in recently implemented marine protected areas.
Aalto, E.A.1*, Dick, E.J.2, MacCall, A.D.2
SEPARATING RECRUITMENT AND MORTALITY TIME LAGS FOR A DATA-POOR PRODUCTION MODEL
1 University of California Davis, 2 Southwest Fisheries Science Center, Santa Cruz
Many production models implicitly incorporate a single time lag for both recruitment and mortality. For populations of breeding adults, deaths occur yearly while the entry of new adults comes from juveniles born potentially many years prior. Models which do not account for this difference in timing will overestimate abundance for a decreasing stock and underestimate increases during a recovery period. We investigate the effect of incorporating unequal recruitment and mortality time lags into Depletion-Based Stock Reduction Analysis (DB-SRA), a data-poor stock assessment method. We find that, for declining stocks with no mortality delay and a recruitment time lag equal to age-at-maturity, estimated overfishing limits (OFLs) are 14-40% lower than those from the original model. The difference in OFL between the lagged-recruitment and lagged-net-production models increases with age-at-maturity and natural mortality rate, suggesting that adjusting for different time lags is most important for longer-lived species. We propose a correction factor for similar models which allows the separation of implicitly equal recruitment and mortality delays.
Abada-Cardoso, A.1,2*, Anderson, E. C. 1,2, Pearse, D. E. 1,2, Garza, J.C. 1,2
INTERGENERATIONAL GENETIC TAGGING WITH SNPS REVEALS REPRODUCTIVE PATTERNS AND HERITABILITY OF SPAWN TIMING IN STEELHEAD
1- Southwest Fisheries Science Center, Santa Cruz Laboratory, 2- University of California, Santa Cruz
Tagging of fish provides insight into life history and ecology, and is critical for conservation and management. The development of single nucleotide polymorphisms (SNPs) and genotyping technology has enabled the use of SNP genotypes as genetic tags that can either be recovered when an animal is recaptured, or through parentage analysis when its progeny are sampled. Here the use of 95 SNPs as intergenerational genetic tags is demonstrated in steelhead. The tags are issued by genotyping broodstock of a population and recovered through genotyping the progeny followed by pedigree reconstruction. Sampling of the broodstock for five years allowed reconstruction of cohort age distribution and revealed a component of fish that spawn at two years of age, contrary to the goal of this hatchery. The pedigree reconstruction provided an estimate of variance in family size and provided an estimate of the rate of iteroparity in this population. The evaluation of correlations between family members in the date of spawning revealed a strongly heritable component to this life history trait. Taken together, these results demonstrate the extraordinary promise of SNP-based intergenerational genetic tagging for providing biological inference in fishes and other high fecundity organisms that is not achievable with traditional physical tags.
Abbott, J.M.*, Stachowicz, J.J.
Relatedness and trait distance as predictors of intraspecific genotype pair performance in eelgrass
Bodega Marine Laboratory, University of California Davis
Genetic diversity within key species has been increasingly tied to the performance of entire communities. In parallel with species diversity experiments, most current genetic diversity studies use only the number of genotypes (genotypic richness) as a metric of biodiversity. However, because functional similarity among genotypes may be influenced by common ancestry, assemblages of more distantly related genotypes might perform better because they encompass a wider niche breath (complementarity). We explicitly tested the influence of genetic relatedness and trait distance on the performance of pairs of genotypes of the clonal seagrass species Zostera marina (eelgrass). We grew pairs of eelgrass genotypes with known pairwise relatedness and trait measurements together in the field and monitored performance. We found that trait distance was positively correlated with pair performance (measured as both leaf growth and plant biomass). Genetic relatedness was only correlated with leaf growth with more closely rated pairs having greater growth. Trait distance, but not relatedness, affected the degree of overyielding, such that pairs with greater trait distance were more likely to perform better than expected based on monocultures. Our results support the hypothesis that functional trait distance, a measure of niche breadth, can influence assemblage performance, but that genetic relatedness is a relatively poor predictor of these ecological distances.
Adreani, M.S.*, Steele, M.A.
REPRODUCTIVE ECOLOGY AND FERTILIZATION RATES OF THE TEMPERATE WRASSE, OXYJULIS CALIFORNICA
California State University Northridge
The seorita (Oxyjulis californica) is an extremely abundant and ecologically important fish on southern California kelp reefs and one of three labrid species inhabiting the temperate waters of California. While previous studies have highlighted aspects of their reproductive biology and feeding behaviors, little was known about their mating behavior and reproductive output. We have quantified the mating success and behaviors surrounding spawning using data collected from northern San Diego county and Santa Catalina Island. Spawning occurs between late May and September in the early morning hours between 0600-0830 and individuals can spawn daily throughout that time. Spawning occurs in large groups of 15-30 individuals in deeper waters adjacent to kelp reefs. Males follow females in tight schools and nudge her abdomen during the brief courtship phase prior to the mass spawn. In addition, a series of fertilization experiments were performed, using serial dilutions of sperm, in order to look more closely at the effects of high concentrations of sperm on fertilization rate. In all cases, fertilization rate was relatively high and comparable to other group spawning species. Even at higher than normal concentrations of sperm, there were no observed deleterious effects on the egg.
Alberto, F.1*, Johansen, M.L.1, Raimondi, P.T.2, Reed, D.C.3, Coelho, N.C.4, Serro, E.A., Macaya, E5
POPULATION GENETICS UNRAVELING OF THE GIANT KELP MACROCYSTIS PYRIFERA
1 University of Wisconsin, Milwaukee, 2 University of California, Santa Cruz, 3 University of California, Santa Barbara, 4 University of Algarve, Portugal; 5- Universidad de Concepcin, Chile
Only recently co-dominant molecular markers have been available for the giant kelp Macrocystis pyrifera. Following decades of exciting ecological research on this model, recent microsatellite research is contributing to extend our knowledge in many areas from gene-flow and meta-population dynamics; biogeography; mating system and inbreeding depression to inter individual heterogeneity and clonality. In this presentation I will synthesize our recent findings in the aforementioned areas and discuss future avenues for the molecular ecology of giant kelp.
Aleman-Zometa, J.G.1*, Robles, C.2, P. Halpin3
MUSSEL BED DISTURBANCE PROCESSES AND MECHANISM PATTERNS
1 – California State University- Los Angeles, 2 – California State University- Los Angeles, 3 – University of California Los Angeles
Established theory maintains that externally imposed disturbances, occurring randomly over the landscape, interrupt competitive exclusion. However, our detailed landscape surveys show that disturbances happen most frequently in sub regions of the bed that support the greatest productivity and hence thickest cover of Mytilus californianus. Mussels stack up to 50 centimeters as surface layer mussels crowd those individuals below them. Crowding reduces the attachment strength of mussels, making them more susceptible to dislodgment, and also lowers the body mass and reproductive condition of those imbedded individuals. A layer of empty shells and debris develops above the rock surface, barring direct rock attachment and promoting lateral attachments in the surface layers. Thus, thickened layers incur more frequent propagating gaps than thinner layers. Stable monolayers form in regions of the bed where predation or low productivity limit the build-up of mussel biomass. Mussel beds are comprised of different disturbance regimes, arrayed predictably over the intertidal landscape, and composed of competitive dominants that show self-limitation in thickened regions while maintaining subordinate species. Global climate change research documents increasing wind and wave action. Understanding the consequences for mussel beds and other layered ecosystems requires a grasp of the interplay of extrinsic and intrinsic limiting factors.
Allen, B.J.*, Browning, J., Fitzgerald-DeHoog, L.
FOOD AND HEAT STRESS IN THE CALIFORNIA MUSSEL: EVIDENCE FOR AN ENERGETIC TRADE-OFF BETWEEN SURVIVAL AND GROWTH
California State University, Long Beach
In response to thermal stress, many rocky shore organisms exhibit physiological changes associated with increased tolerance to subsequent high temperatures. Although presumably adaptive, activation of the heat shock response requires a significant energetic investment and therefore may impose a trade-off between survival and other life history traits. In this study, we investigated the effects of chronic heat stress and variation in food availability on the relative allocation of resources to competing demographic parameters in the California mussel, Mytilus californianus. Our data provide support for the idea that acclimatory responses to temperature stress can drive trade-offs among traits, as predicted by theory. Chronic heat stress invoked a cost to individuals, expressed as a reduction in shell growth or size-specific tissue mass in the field and laboratory, respectively. However, prior thermal conditioning resulted in higher survival following acute exposure to more extreme temperatures. Overall, mussels receiving less food exhibited poor condition and survival, suggesting that individuals with limited access to resources are at greater risk as they are less able to mitigate potential costs of thermal stress through physiological mechanisms. Accurately forecasting effects of climate change will require understanding how variation in local resource availability modifies organismal responses to different temperature regimes.
Amsler, C.D.1*, McClintock, J.B.1, Baker, B.J.2
CHEMICAL MEDIATION OF PREDATOR-PREY AND MUTUALISTIC INTERACTIONS OF SEWAWEEDS AND INVERTEBRATES ON THE WESTERN ANTARCTIC PENINSULA
1 – University of Alabama at Birmingham, 2 – University of South Florida
Macroalgae (seaweeds) dominate hard bottom areas along the Western Antarctic Peninsula to depths of up to 40 m or more. Most of the macroalgae are chemically defended from a variety of macro- and mesograzers but harbor very high densities of amphipod mesograzers. The amphipods benefit from living on the large, chemically-defended macroalgae because they gain refuge from fish which are their primary predators. These amphipods do not consume most of the macroalgal species, but are of benefit to the macroalgae by keeping them relatively clean of epiphytic microalgae and filamentous macroalgae. They do, however, appear to have selected for a relatively high incidence of filamentous algal endophytes in some of the larger macroalgae. These endophytes can be, but are not always, detrimental to the hosts. Hence, overall, this represents a community-scale mutualistic relationship between the dominant macroalgal assemblage and the abundant amphipod assemblage that is mediated, at least in part, by the macroalgal chemical defenses.
Anderson, K. M.*, Nienhuis, S. B., Schultz, J. A., Harley, C. D. G.
IN A HIGH CO2 WORLD, MARINE HERBIVORES DO NOT LOSE THEIR APPETITES
Department of Zoology, University of British Columbia
Ocean acidification is predicted to be one of the most wide reaching threats facing marine biota. Given this expectation, how do we prioritize what biological impacts of ocean acidification to study? As many organisms respond to stress by altering their metabolism, it seems reasonable to expect trophic interactions to vary in response to this environmental stressor. Here we present data from a series of feeding trials with multiple marine herbivores (crustacean, echinoderm, and gastropod) exposed to either ambient or elevated CO2 levels. In all feeding trials, we found no evidence of variation in feeding rates between herbivores exposed to elevated CO2 and those exposed to ambient conditions. We propose that this series of null results is indicative of an overall trend: marine herbivores will likely not respond to increased CO2 by directly altering their grazing rates. However, we draw attention to other mechanisms by which the total magnitude of herbivory may change owing to the combined effect of mass-specific feeding rates (larger herbivores eat more) and lower growth rates under conditions of elevated CO2. We propose that the sharing of null results such as these is integral in continuing to generate new and innovative hypotheses, while streamlining research efforts.
Anderson, L.M.* Martone, P.T.
WHAT A DRAG: BIOMECHANICAL CONSEQUENCES OF INTERTIDAL ALGAL EPIPHYTISM
University of British Columbia
Although the intertidal zone is narrow, it boasts a large number of diverse algae. Some grow epiphytically, decreasing competition for settlement space, light, and nutrients. Associated hosts generally experience negative effects from increases in the above interactions. But, what are the mechanical consequences of epiphytism in habitats where wave velocities can exceed 10-20 m/s, and threaten to dislodge seaweeds? To answer this question, I studied the brown algal epiphyte, Soranthera ulvoidea, and its red algal host,Odonthalia flocossa, in the mid intertidal zone of British Columbia. I used a water flume to measure drag on hosts before and after removing their epiphytes. Epiphytes increased drag on hosts by approximately 50% at each test velocity, and significantly increased host dislodgement risk. As flow increased, drag on epiphytes also increased, however, drag on epiphytes was less when attached to hosts, as opposed to drag on epiphytes alone. In sum, predicted breakage velocities for epiphytized hosts and epiphytes were not significantly different, making it just as likely for a host to break as for an epiphyte to detach from its host. In this manner, hosts are slightly impacted negatively by epiphytes, while epiphytes gain a hydrodynamic benefit from growing on another alga.
Anderson, S.S. *
THE NATURAL HISTORY OF VEHICLE-ASSOCIATED MORTALITY: UNDERAPPRECIATED, ELEVATED ROAD KILL ACROSS THE COASTAL ZONE
California State University Channel Islands
Roads, vehicles, and vessels of all sorts can have profound impacts on the abundance and distribution of vertebrates, with direct mortality (i.e. road kill) the most obvious such effect. I have been examining road kill across the globe (eastern Turkey, coastal Gulf of Mexico, and coastal California) since 2007. While the individual species killed varies, overall mortality is most consistently seen in transitional regions (ecotones) or edges and reaches it highest level proximate to coastal wetlands. Patterns are clearest within my most intensively-sampled region of southern California (more than 3,100 observed kills during more than 4,300 individual surveys amounting to a total of 56,000 km driven over the past 6 years). Many factors such as landuse, roadside barriers, maximum speed limit, and vehicle traffic are correlated with kill rates, but the best overall predictor appears to be the gross positioning of the particular road/path segment within transition zones (wildland-urban interface, etc.) and proximity to the coast. For example, in the Santa Monica Mountains (a coastal range ~50×10 km bisected by 282 km of arterial roads) 4,601 781 (mean se) large-bodied animals are killed annually, spanning abundant (e.g. 98 coyote kills), common (e.g. 9 owl kills), and rare (e.g. 3 badger kills) species of concern. Kill rate along the ranges perimeter exceeds that within its core. Despite such persistent mortality, protected area and ecological restoration efforts rarely adequately appreciate or manage for this threat. While difficult to confirm, a similar patter in neuston vertebrate kills may be occurring within heavily traveled shipping lanes associated with coastal shipping centers. My new citizen science iPhone app (Splatter Spotter), currently in use in 39 counties, is helping to elucidate these patterns.
Andrews, K.S.*, Williams, G.D., Samhouri, J.F., Levin, P.S.
Indicators, status and trends of anthropogenic pressures in the California Current.
Northwest Fisheries Science Center, NOAA Fisheries
As human population size and demand for seafood increases, human activities in the ocean (e.g., fishing and shipping activity) and on land (e.g., pollutants and runoff from agricultural activities) must be incorporated into management. Because these pressures originate from human activities, we should be able to assess current and historic levels and predict future levels of the pressure. Predictions should then be useful in testing various management scenarios. Here, we evaluated and chose indicators best suited to capture the trends and variability of each pressure. Then we gathered data sets and created a time series describing the status and trends of each pressure. Many anthropogenic pressures were relatively constant over the short-term and within historic levels of the entire time series. However, inorganic and organic pollution, direct human impacts and invasive species decreased over the short-term, while dredging, shellfish aquaculture, coastal engineering, commercial shipping activity and marine debris increased over the short-term. Seafood demand, sediment and freshwater input were constant over the short-term, but were above historic levels, while offshore oil and gas activity and benthic structures were at historically low levels. The cumulative effects of these pressures are difficult to interpret due to datasets that vary in duration.
Asef, T.S.1*, Whitcraft C.R.1, Gaskin, J.F.2
ASSOCIATING GENETICALLY DIVERSE TAMARISK INVADERS WITH THEIR IMPACTS IN A SALT MARSH ECOSYSTEM
1 California State University Long Beach, 2 United States Department of Agriculture, Agricultural Research Service, Northern Plains Agricultural Research Laboratory
Invasive tamarisk impacts include increasing soil salinity, decreasing water content, and causing a shift in food web structure. The tamarisk species originally introduced to the US in the 1800s have hybridized and have recently been documented invading salt marsh systems in Southern California. AFLP was used to determine genetic identity of each individual salt-marsh invading tamarisk. Genetic identities and microhabitat types were linked to data about age, height, soil salinity, distance to major features, C:N ratios (proxy for palatability), and infauna communities. Abiotic impacts of tamarisk (soil salinity, water content) depended on microhabitat, as did tamarisk tree morphology (trunk volume, DBH, and canopy area), and infauna community composition. Tamarisk altered abiotic factors in the upland and upstream microhabitats and altered infauna community composition in the marsh microhabitat. 17.8% of sampled trees were hybrids of T. ramosissima x T. chinensis. The remainder were pure T. chinensis. Tamarisk genetic identity did not influence abiotic factors or invertebrate communities. The geographic, biotic, and abiotic similarities between genetic types of tamarisk show that the invasion occurred during a low salinity event and was not in situ hybridization. Understanding the tamarisk invasion in salt marsh systems can help structure removal efforts.
Bal, G.*, Ward, E.J., Scheuerell, M., Holmes, E.E.
TOWARD A METAPOPULATION MODEL TO IMPROVE THE CONSERVATION OF ONCORHYNCHUS SPECIES
NOAA, Northwest Fisheries Science Center Seattle, WA.
Although spatial structure is known to be of primary importance for species management, the metapopulation structure of anadromous fish populations is rarely considered, and thus, the importance of straying and spatial structure on population viability is not well understood. We address this shortcoming by developing a new metapopulation model based on statistical fits to individual mark-recapture data in contrast to more traditional, mechanistic models. Our use of a hierarchical Bayesian framework allows us to explicitly address within and among population variation in demographics. Here we apply this framework to Chinook salmon (Oncorhynchus tshawytscha) from the Columba River, which are listed as endangered under the Endangered Species Act. Our analyses focused on differences in 1) river and marine survival and 2) straying rates as functions of rearing origin (wild versus hatchery) and age. These analyses indicate that straying is significantly higher in hatchery fish, and both ocean and river survivals are lower. Further analyses are focusing on estimating how stray rates are affected by individual factors (e.g., size) and spatial location. Once fully developed, our model will incorporate the effects of spatially varying risk factors and environmental parameters and allow us to develop metapopulation forecasts over the entire salmon life-cycle.
Barazandeh, M.1,2*, Davis, C.S.1, Neufeld, C.J.2,3, Coltman, D.W.1 Palmer, A.R.1,2
Spermcast mating in the Pacific gooseneck barnacle, Pollicipes polymerus
1 – University of Alberta, 2 – Bamfield Marine Sciences Centre, 3 – Quest University Canada
Most free-living barnacles are hermaphroditic and eggs are presumed to be fertilized by pseudo-copulation or self-fertilization. The northeast Pacific gooseneck barnacle, Pollicipes polymerus, is believed to be a mandatory cross-fertilizer. Furthermore some isolated P. polymerus, well outside the range a penis could reach, have fertilized egg-masses. They must therefore either self-fertilize or obtain sperm from the water. This latter possibility has never been considered in barnacles. However, we observed some P. polymerus individuals leaking sperm between their opercular plates during low tide. Significantly, our genetic evidence from 16 single nucleotide polymorphisms (SNP) confirms that isolatedP. polymerus can capture sperm from the water. All 37 embryo masses tested had at least one locus with a non-parent allele, and 36 had non-parent alleles at two or more loci. Remarkably, even in isolated pairs bearing egg masses (individuals adjacent to one neighbor but multiple body lengths from others), individuals still obtained some sperm from the water. These observations reject the possibility of exclusive self-fertilization in Pollicipes polymerus and confirm spermcast mating for the first time in any species of barnacle. Moreover, our descriptive studies indicate some interesting patterns in P. polymerusmating strategies.
Barner, A.K.*, Hacker, S.D., Menge, B.A.
Community structure and diversity across environmental stress gradients and scale in THE Pacific Northwest rocky intertidal
Department of Zoology, Oregon State University
Despite a large body of literature dedicated to the study of the drivers of community structure, we have a poor understanding of the influence of multiple, interacting variables on communities, and how this varies from local to regional scales. Thus, we asked, (1) What are the current patterns and drivers of community structure and diversity of intertidal communities along abiotic stress gradients? and (2) Do these relationships persist across varying spatial scales? We conducted multi-scale community surveys in summer 2012 at 9 rocky intertidal sites, nested within 3 capes along the Oregon coast. At each site, we surveyed assemblages across two abiotic stress gradients (tide height and wave exposure). For each survey, we measured physical covariates and recorded the abundance and spatial pattern of all space occupiers within the survey grid. We calculated 3 indices of diversity for each survey (Shannons index, evenness, and richness). We assessed patterns of community structure and diversity across scale and abiotic gradients using generalized linear mixed models and variance partitioning. We found that wave exposure and tidal height affect both the functional structure of the community and its diversity, and that that the effect of abiotic factors depended on spatial scale.
Barnett, L.A.K.*, Baskett, M.L., Botsford, L.W.
EFFECTS OF CLIMATE CHANGE AND MPA MANAGEMENT ON PERSISTENCE AND FISHERY YIELD: THE ROLE OF MATERNAL-AGE-DEPENDENT OFFSPRING TRAITS
University of California Davis
Although implementation of marine reserves is often proposed to protect ecosystems from climate change impacts, approaches for accomplishing this objective have been primarily qualitative. We address this shortfall in the progression toward a quantitative understanding by incorporating temporal environmental variation in a dynamic, spatially-implicit, age-structured model with density dependence and both climatic and maternal influences on larval survival. In an application to gopher rockfish (Sebastes carnatus) we demonstrate that the probability of persistence and fishery yield increases with a slight delay in spring transition timing (causing a temporal mismatch between S. carnatus larvae and their prey), but decreases with a greater delay or any advancement. Inclusion of maternal-age-dependent larval release timing and larval energy reserves generally decreases total yield and the fishing mortality the population can withstand and still persist (Fpersist). Fpersist was greatly influenced by age at recruitment and natural mortality. Compared to conventional management, reserve management generally decreased total yield and increased Fpersist, as expected, but actually increased yields in some cases when spring transition was greatly altered.
Barney, B.T. *, Palumbi, S.R.
Searching for selection at highly local scales evidence for thermal selection in California mussels
Hopkins Marine Station, Stanford University
We typically think of oceanic thermal gradients as latitudinal increases in temperature towards the equator. However, within the rocky intertidal zone, significant differences in body temperature between organisms can exist across centimeter scales due to variable wave, wind, and solar exposure. This fine-grained thermal mosaic can be a challenging environment for the survival of sessile organisms: once settlement occurs, that individual is committed to the long-term thermal regime at that location no matter what its internal intrinsic thermal adaptation. If this phenotype-environment mismatch is strong enough, highly localized natural selection can occur. Here we investigate the California mussel (Mytilus californianus) between neighboring mussel beds under different thermal regimes in Pacific Grove, CA. We used RNA-Seq and transcriptomic techniques to discover single nucleotide polymorphisms within expressed mRNA transcripts from sun-exposed and shaded mussels and found signals of natural selection at a scale of a few meters. Of 13 genes found to be under site-specific selection, five coded for carbohydrate metabolism processes. Because an animals response to temperature is related to its intrinsic metabolic rate, this divergence may suggest the potential for localized natural selection on thermal tolerance in this species.
Barshis, D.J., Ladner, J.T., Oliver, T.A. 1, Seneca, F.O., Traylor-Knowles, N., S.R. Palumbi
GENOMIC SIGNATURES OF INCREASED STRESS TOLERANCE IN REEF CORALS
Hopkins Marine Station of Stanford University
Environmental changes are currently driving dramatic declines in reef building corals and the situation is expected to worsen as anthropogenic climate change intensifies. However, corals have been found to differ substantially in physiological susceptibility to environmental stress. The molecular mechanisms behind these differences in coral stress tolerance are not well known, yet are critical to the persistence of both corals and coral reefs in the future. Here, we compare conspecific thermally sensitive and thermally tolerant corals using advances in DNA sequencing technologies (RNA-Seq) to identify the molecular pathways underlying differential physiological tolerance limits. We subjected these phenotypically distinct corals to simulated bleaching stress and found that tolerant corals had higher pre-stress expression and reduced reaction to thermal stress across 60 genes, as compared to the sensitive corals. These frontloaded transcripts included not only established thermal tolerance genes such as heat shock proteins and antioxidant enzymes, but also a much broader array of molecular processes such as apoptosis regulation, tumor suppression, innate immune response, and cell-cell adhesion. These data show that thermal tolerance involves differential regulation of a diversity of pathways including, but not limited to, previously well-characterized responses. We propose a hypothesis wherein constitutive frontloading enables an individual to maintain physiological resilience despite frequently encountered environmental stress.
Bautista, J.D., Allen, L.
REPRODUCTIVE BIOLOGY OF BARRED SAND BASS, (PARALABRAX NEBULIFER)
FROM SOUTHERN CALIFORNIA
California State University Northridge
Years of intense fishing pressure has caused the fishery of the barred sand bass, (Paralabrax nebulifer) off southern California to decline precipitously in the first decade of the 21st century. The large aggregations that this species forms during their summer spawning season have left them vulnerable to fishermen who remove them by the tens of thousands each summer. Commercial fishing has been prohibited since the 1950s, but the increasing popularity of this sport fish and relative ease of capture has drawn in thousands of anglers annually. Specifically this proposed study into the reproductive biology of barred sand bass aims to document, for the first time, the gonado-somatic index (GSI) for both male and female for a full year and determine batch fecundity for a wide size range of females. Understanding the reproductive cycles and the duration of energy allocation towards reproduction is important for the proper management of this fishery. Historically, barred sand bass have played a prominent role in the recreational fishing industry of southern California and must be protected and properly managed to prevent further decrease in the stocks, the loss of genetic diversity, the shifting of size and sex classes, and the ultimate collapse of the fishery.
Bay, R.B., Palumbi, S.R
GENETIC ADAPTATION ACROSS A TEMPERATURE GRADIENT: PATTERNS OF NATURAL SELECTION INACROPORA SURCULOSA ON A BACKREEF
Hopkins Marine Station, Stanford University
One of the most commonly implicated factors in large-scale coral bleaching events is thermal stress driven by climate change. However, bleaching susceptibility varies both between species and among individuals of the same species. In this study, we use a genomic approach to investigate the contribution of genetic adaptation to bleaching resilience in Acropora surculosa colonies from backreef pools on Ofu Island in American Samoa. These pools experience different temperature regimes, with one pool regularly exceeding 34C. Previous studies have shown that individual colonies from these pools vary in their ability to resist bleaching when subjected to thermal stress. The aim of our study is to characterize individual genetic variants that may be associated with increased resilience to thermal stress. Using RNA-seq, we sequenced transcriptomes for 39 A. hyacinthus colonies across the natural temperature gradient in the backreef on Ofu. We also collected temperature data from each colony over the span of 6 months. From the full transcriptomes, we identify single nucleotide polymorphisms (SNPs) and test for associations with temperature regime, finding a broad range of genes and biological processes that may be associated with thermal tolerance and bleaching resistance in A. surcolosa.
Beas-Luna, R1*. Field, J.2, Malone, D. 1, Novak, M.3, Carr, M.1
PREDICTING THE EFFECTS OF FISHING IN KELP FOREST OF CENTRAL CALIFORNIA.
1- University of California, Santa Cruz, 2- Southwest Fisheries Science Center, NOAA , 3 – Oregon State University
Kelp forests along the coast of California are highly productive ecosystems that produce a number of ecosystem services, including recreational and commercial fisheries. However, the ecosystem-wide consequences of fishing on the structure and functions of these forest ecosystems are not well understood. We developed an ecosystem model for kelp forests of Central California to refine our understanding of the major direct and indirect species interactions in this system and to inform ecosystem-based management approaches. We used the ecosystem model to simulate the effect of changes in fishing pressure on a single species on other species it directly interacts with (i.e. as predator, prey or competitor) and on those it indirectly influences through interactions with other species in the ecosystem. We also used the model to determine whether the direct and indirect effects of removing a fished species differs depending on the species targeted (e.g., Lingcod, Cabezon, Black & Yellow and Gopher Rockfishes). To address these questions we developed a network of 16 nodes (i.e. species with similar functional roles within the ecosystem) that included four species targeted by commercial and recreational fishing. We found that the extent to which interactions among species and groups are altered across the ecosystem differed markedly among the four-fished species. For one species, Lingcod, fishing caused a change only for species interacting directly with Lingcod. For another species, Black and Yellow Rockfish, changes in fishing pressure led to more widespread changes from the fished species to the primary producers in the forest. Results like these are key to predicting how ecosystem-wide effects of fishing vary among the species targeted for fishing in an ecosystem.
Becker, B.J. 1*, Behrens, M.D. 2, Henzler, C.M. 3, Hoaglund, E.A. 3, Shevalier, Y.R.A. 1, LeMay, B.K.1
DETERMINING DISTRIBUTION OF LARVAL PACIFIC GEODUCK CLAMS (PANOPEA GENEROSA) IN PUGET SOUND USING A NOVEL SAMPLING APPROACH
1 University of Washington Tacoma, 2 Pacific Lutheran University, 3 University of California Santa Barbara
Quantifying connectivity among populations of bivalves has implications for key conservation and management questions. Traditional sampling techniques, such as nets and pumps, collect larvae during discrete periods, limiting ability to capture transient pulses. These approaches are further limited by the resource-intensive task of sorting and identifying larvae from the rest of the plankton, restricting the number of time points that can be sampled. We use a novel approach, passive larval trapping, which takes time-integrated samples, paired with Fluorescent In Situ Hybridization with Cell Sorting (FISH-CS), which automates the sorting and identification processes, to map larvae of geoduck clams in Quartermaster Harbor, Puget Sound, WA. Our findings indicate that although there is a low level of small larvae in the Harbor throughout the season, a pulse of larger larvae were captured in early summer. In contrast, medium sized larvae were found in the slow-moving inner harbor. Our results imply that at least some of the larvae were retained in the harbor for their entire planktonic larval duration. Our results represent the first published use of FISH-CS and the first observation of geoduck larvae in situ. This approach will be used to further study the connectivity of commercially important shellfish populations.
Bell, T.W.*, Cavanaugh, K.C., Reed, D.C., Siegel, D.A.
SEASONAL BIOMASS PATTERNS OF GIANT KELP ACROSS ITS DOMINANT RANGE IN THE NE PACIFIC
University of California Santa Barbara
Recent advancements in the remote estimation of abundance and canopy biomass of giant kelp (Macrocystis pyrifera) have allowed researchers to examine dynamics over large temporal and spatial scales using LANDSAT 5 Thematic Mapper satellite imagery. Publications utilizing this technique have found that disturbance, nutrient availability and oceanography cycles drive changes in kelp biomass, recruitment and mortality, however these studies have focused on selected kelp forests in the Santa Barbara Channel and around the Monterey Peninsula. Here we present the recent expansion of this process to cover the entire dominant range of giant kelp in the Northeast Pacific (Santa Cruz, CA – Punta San Hipolito, Baja California Sur, Mexico) throughout the ~28 year life of the satellite (1984 2011). By examining the seasonal biomass patterns across this multi-decadal timespan, a better understanding of the impact of large scale disturbance and nutrient regimes on regional giant kelp populations can be made, as well as the assessment of the biomass variability of these patterns over time.
Benes, K.M.*, Perini, V., Bracken, M.E.S.
NUTRIENT PHYSIOLOGY OF FUCUS VESICULOSUS ACROSS LOCAL, REGIONAL, AND TEMPORAL SCALES IN THE GULF OF MAINE
Marine Science Center Northeastern University
In intertidal habitats, ambient nutrient concentrations can be mediated by tides, weather, and large scale processes that drive differences across latitudes causing variation in the nutrient physiology of organisms within and among populations. The alga, Fucus vesiculosus acts as foundation species on North Atlantic rocky shores and has wide geographic and tidal distributions. In the Gulf of Maine (GoM), its large geographic distribution results in up to a 18-fold difference in ambient nutrient levels experienced among populations and its wide intertidal distribution causes up to a 13-fold difference in nutrient acquisition time within populations. However tissue nitrogen concentrations do not differ among populations in the GoM, and across its tidal distribution, low shore Fucus have only 1.05-fold higher tissue nitrogen content compared to high shore Fucus. Seaweeds can adjust their uptake efficiency (e.g., Vmax/Km) as one mechanism to account for limited access to nutrients. Experiments showed high shore Fucus were 1.36-fold more efficient at nitrate uptake than low shore Fucus resulting in generally higher uptake rates at low, biologically relevant, ambient nitrogen concentrations. Other physiological phenomena such as desiccation and/or internal nitrogen pools may also be important in regulating tissue nitrogen content in this species.
Benkwitt, C.E.*, Hixon, M.H.
TWOS COMPANY, SIXTEENS A CROWD: BEHAVIOR OF INVASIVE LIONFISH IN GROUPS
Oregon State University
The Indo-Pacific red lionfish (Pterois volitans) is an invasive marine predatory fish that is threatening coral-reef ecosystems in the Western Atlantic. Lionfish populations in the Atlantic are currently growing exponentially, leading to much higher population densities in their invaded range compared to their native range. As populations continue to grow, lionfish may be spending more time with conspecifics, which could lead to altered behavior, such as cooperative hunting or increased intraspecific aggression. To determine whether behavior changes at various densities, I conducted behavioral observations of 115 lionfish on 24 patch reefs in the Bahamas. Lionfish spent similar amounts of time hunting and had comparable per capita strike and kill rates at different densities, with lionfish on all reefs hunting more at dawn and dusk versus midday. There was little cooperative hunting and no aggression. At higher densities, however, lionfish foraged more often off the patch reefs, especially at dawn and dusk. This pattern suggests that higher densities of lionfish may have depleted prey on reefs to the extent that they are now altering prey communities in surrounding sand and seagrass areas. If this is the case, then invasive lionfish are having broader effects beyond those already documented on coral reefs.
Berumen, M.L.1,2*, Almany, G.R.3, Planes, S.4,5, Jones, G.P.3, Saenz-Agudelo, P.1, Harrison, H.B.3, Thorrold, S.R.2
ADVANCES IN UNDERSTANDING LARVAL DISPERSAL PATTERNS VIA PARENTAGE ANALYSIS OF CORAL REEF FISHES
1- King Abdullah University of Science and Technology, 2 –
Woods Hole Oceanographic Institution, 3 – James Cook University, 4 –
Centre de Recherche Insulaire et Observatoire de l’Environnement (CRIOBE), 5 – Universite de Perpignan
The use of marine protected area (MPA) networks to sustain fisheries and conserve biodiversity is predicated on two critical yet rarely tested assumptions. Individual MPAs must produce sufficient larvae that settle within that reserves boundaries to maintain local populations while simultaneously supplying larvae to other MPA nodes in the network that might otherwise suffer local extinction. Here, we present the results of genetic parentage analyses used to make empirical measurements of larval dispersal patterns in several coral reef species ranging from clownfish to commercially important groupers. As parentage studies become more common, some themes are emerging. Successful settlement of larvae on their natal reef (self-recruitment) appears to be persistently high enough to play an important demographic role. Inter-annual assessment of dispersal patterns reveals that dispersal may vary greatly through time and among study species, suggesting that the biology and/or behavior of the species (coupled with physical dynamics) plays an important role in realized dispersal patterns. In addition to validating or informing MPA design and function, parentage analysis has the potential to help address significant ecological issues, such as generating empirical larval dispersal kernels and addressing drivers of fitness in populations.
Bjelde, B.E*, Todgham, A.E.
THERMAL PHYSIOLOGY OF THE FINGERED LIMPET, LOTTIA DIGITALIS UNDER IMMERSION AND EMERSION CONDITIONS
San Francisco State University
Intertidal ecology is changing in the face of increasing global temperature; however, the physiological mechanisms underlying these changes remain unclear. To better understand the thermal physiology of intertidal organisms to natural increases in temperature, we compared the physiological response of the fingered limpet, Lottia digitalis, to thermal stress when exposed to elevated temperatures under emersed or immersed conditions. Using measurements of heart rate and metabolic rate (MO2) as indices of performance, we examined thermal sensitivity and upper thermal tolerance limits of limpets to increases in temperature. Thermal limits of cardiac performance were calculated as breaks in heart function, measured as break point temperatures (BPT). Oxygen consumption, used as a proxy for MO2 was measured from 15-40C at 5C intervals. Limpets exposed to a thermal ramp under emersed conditions maintained heart function to a higher temperature (3-5C higher) than limpets exposed to the same heating while immersed. MO2 was higher and more variable in emersed limpets compared to immersed limpets, where MO2 decreased with increasing temperature. Field temperature logger data combined with our physiological measurements suggest that L. digitalis are currently living close to their temperature tolerance limits and may not have the capacity to keep up with increasing environmental temperatures.
Bond, M.H., Armstrong, J.B.
flexibility in gut size and life history diversity in a facultatively anadormous salmonid
University of Washington, School of Aquatic and Fishery Sciences
Anadromy is a life history strategy where oceangoing individuals trade off the risks of the ocean with increased growth potential relative to freshwater environments. However, some salmonid species are facultatively anadromous and iteroparous, adding additional complexity to the marine-freshwater tradeoff. One such species, Dolly Varden, display enormous variation in the timing, duration and annual patterns of anadromy. In the Chignik Lakes watershed, Southwestern Alaska, we used Dolly Varden otolith microchemistry to demonstrate that the probability of anadromy increases with each year of life until age four, then declines to near zero by age six. However, many individuals live in freshwater for five or more years after retiring from anadromy. To survive in low productivity freshwater environments, these large bodied individuals acquire nearly their entire annual energy budget from a five week pulse of energy rich sockeye salmon eggs. We measured gut size before and after the availability of salmon eggs and performed bioenergetic simulations to show that survival during nearly ten egg-free months each year is driven by an atrophy in gut machinery and near fasting until salmon spawn each fall. Without sockeye, large resident phenotypes may not persist, illustrating the importance of resource availability in shaping life history patterns.
Borras-Chavez, R.1*, Flores, V. 1, Gonzlez, A. V. 2, Beltrn, J. 1 and B. Santelices 1
COALESCENCE IN KELPS. HISTOLOGICAL AND MORPHOLOGICAL DESCRIPTION IN LESSONIA SPICATA
1-Pontificia Universidad Catlica de Chile, 2-Universidad de Chile
Coalescence in red algae implies histological and ultra-structural changes suggesting a more complex process that the simple fact of two individuals living in close proximity. Field observations indicated that in the kelp Lessonia spicata, holdfasts can fuse with each other showing scars as consequence of this process but maintaining each, its genetic independency. This suggests that coalescence also occurs in a group of algae with great ecological importance, capable of construct underwater forests of high complexity. To formally describe the histological process that allows fusion in L. spicata, coalescence was induced in isolated sporophytes cultivated under laboratory condition. Once fused, the coalesced disks were fixed and then processed. Thin and semi-thin section were obtained from the contact zone and observed with electronic and transmission microscopy. In early stages of fusion, a thinning and then reduction of the external cell wall was observed in the contact zone. In advanced stages of fusion, the meristodermic cells with thick cell wall and a great amount of organelles change into cortical cells with polygonal shape, few organelles and larger size. Later, these new cortical cells will establish plasmodesmata, communicating cells from different individuals.
Boyer, K. E.1*, Reynolds, L. K. 1,2, Carr, L.A1,3
NOVEL ROLE AND INTERACTIONS OF AN INTRODUCED AMPHIPOD IN SAN FRANCISCO BAY EELGRASS BEDS
1 – Romberg Tiburon Center, San Francisco State, 2 – University of Virginia, 3 – University of North Carolina at Chapel Hill
Through a series of experiments, we evaluated the role of an invasive amphipod, Ampithoe valida, in eelgrass (Zostera marina) beds in San Francisco Bay (SFB). Not known to consume eelgrass in its East Coast, the amphipod can produce extensive damage to blades and inflorescences in this invaded habitat. In an experiment in which SFB A. valida was offered eelgrass from both SFB and its native Virginia, SFB tissues were by far the preferred choice and were consumed even when a common macroalga was also offered. Tissue nitrogen concentration was higher in SFB tissues, but neither nitrogen nor phenolic content of eelgrass tissues provide clear or adequate explanations for responses. Another experiment found two common native fishes of SFB were much less effective at reducing abundances of A. valida than fish from the amphipods native range; hence, in SFB, amphipod population growth/effects may be enhanced by reduced predation pressure. Other results indicate the amphipods preference for flowering over vegetative tissues and that the former increase refuge from native predatory fish. This invasion presents concerns for eelgrass restoration in SFB, where restoration projects use intact flowering shoots for seeding, restored plants have especially low C:N, and predators may take time to arrive.
Bramanti L.*, Edmunds P.J.
EFFECTS OF CLIMATE CHANGE ON THE POPULATION DYNAMICS OF SCLERACTINIAN CORALS: A DEMOGRAPHIC MODEL FOR POCILLOPORA DAMICORNIS
California State University Northridge
Few studies have attempted to forecast the effects of projected changes in atmospheric pCO2 and seawater temperature at a population level. Using empirical analyses of the effects on survival and calcification of early life stages of Pocillopora damicornis, we forecasted the consequences of climate change and Ocean Acidification on the population dynamics of this coral. We constructed a size-based markov-chain demographic model for a population of P. damicornis in Taiwan, and projected the structure over ~100 y under differing climate change scenarios. The simulations incorporated larval mortality due to increases in temperature and pCO2. Results suggest that increase of temperature (26.4C to 29.6C) and pCO2 (380 to 900 ppm) could lead to non-linear reductions in population density from 11.6 to 2.3 colonies m-2 in 150 y. The drastic decrease happens with larval survival at < 80%, suggesting the importance of early life stages in the population dynamics of this species. When the effects of OA on colony growth rates are incorporated, density reduces to 2.3 in less than 40 years. Our model can be expanded to a metapopulation approach linking the dynamics of multiple populations by a connectivity matrix.
Briggs, A.A.1*, Young, H.S.2, McCauley D.J.3, Hathaway, S.A.4, Dirzo, R.5, Fisher, R.N.4
SPATIAL SUBSIDIES AND HABITAT STRUCTURE: THE EFFECTS OF SEABIRD GUANO ON ISLAND GECKOS IN THE TROPICS
1 – California State University, Northridge, 2 Harvard University, 3 University of California, Berkeley, 4 Western Ecological Research Center, U.S. Geological Survey, 5 Stanford University
Spatial subsidies can influence consumer abundance, however little is known about how subsidies may affect consumer body condition and trophic ecology. Whether changes in vegetation structure commonly associated with subsidies play an important role in driving consumer responses to subsidies remains poorly understood. To address these questions, we studied changes in abundance, diet, trophic position, and morphometrics of two gecko species (Lepidodactylus spp.) in the Central Pacific in response to direct, bottom-up effects of subsidies, and to indirect subsidy effects, mediated by structural changes of vegetation communities. Using islets on Palmyra Atoll that strongly vary in subsidy input from seabirds and in habitat complexity, we found that subsidy level had no impact on the abundance of either gecko species. However, geckos in highly subsidized forests had greater body size, body condition, diet diversity, and trophic position than geckos found in low subsidy forests. Separating the effects of subsidy input and habitat structure on gecko responses showed that gecko trophic position was positively correlated with subsidy level, while body size and body condition were associated with habitat structure. Our results suggest that variation in subsidy levels may drive important responses in consumers, and moreover may drive systematic changes in foodweb structure.
Brown, D.*, Edmunds, P. J.
EFFECTS OF HETEROTROPHY ON CALCIFICATION OF TAXONOMICALLY DIVERSE CALCIFYING CNIDARIANS IN A HIGH pCO2 ENVIRONMENT
California State University Northridge
We tested the hypothesis that the scleractinian, Pocillopora meandrina, and the hydrocoral, Millepora platyphylla, respond differently to increased pCO2 due to differential utilization of particulate food. To test this hypothesis, pCO2 treatments of 380atm and 710atm, were crossed with feeding treatments created through the supply of unfiltered seawater (ambient), filtered seawater (10m), or seawater enriched with natural zooplankton (augmented). M. platyphylla was unaffected by increased pCO2 at ambient and depleted feeding treatments, but high pCO2 increased calcification 19% in the augmented feeding treatment. P. meandrina was unaffected by increased pCO2 at the ambient feeding treatment, but increased pCO2 decreased calcification 32% and 29% for augmented and depleted feeding treatments, respectively. In ambient and depleted feeding treatments, calcification of M. platyphylla, may be nutrient limited, with the effect removed with additional zooplankton. P. meandrina interacts with food in different ways, as calcification was depressed by pCO2 both when additional zooplankton were supplied and when the smallest particulates were removed, but not with access to ambient seawater. We speculate that the differences between scleractinian and hydrocorals in their response to pCO2 as a function of food supply may reflect the evolutionary origins of these taxa in ancient seas differing in chemical composition.
Brown M.B., Edwards, M.S.
PHYSIOLOGICAL EFFECTS OF CLIMATE CHANGE ON THE GIANT KELP MACROCYSTIS PYRIFERA
San Diego State University
Anthropogenic climate change is a major threat to global biodiversity and ecosystem health. Since the Industrial Revolution, sea surface temperatures have risen concurrently with atmospheric warming. In addition, ~30% of all CO2 emissions have dissolved into the worlds oceans, making them more acidic and altering their carbon chemistry. While many studies have examined the effects of climate change on marine organisms, not all groups have received an equal amount of research. Specifically among the algae, much of the focus has been on phytoplankton and coralline macroalgae, and we know comparatively little of how climate change will affect non-calcifying species. For this study we chose the giant kelp Macrocystis pyrifera. Macrocystis is the primary canopy-forming kelp along the southern coast of California, providing habitat for numerous species, some of which are associated only with kelp forests. We cultured apical tips of Macrocystis for one month in laboratory mesocosms under four conditions; ambient, elevated temperature, elevated CO2, and elevated temperature and CO2. Growth and photosynthesis were measured weekly, and chemical composition was measured at the end of the experiment. We observed significant differences between treatments, with kelps cultured under elevated temperature and/or CO2 showing drastically different responses from those cultured under both factors together.
Brown, N.E.1, Harley, C.D.G.1, Therriault, T. W. 2
OCEAN ACIDIFICATION REDUCES MUSSEL RECRUITMENT IN MARINE FOULING COMMUNITIES
1 University of British Columbia, 2 Fisheries and Oceans Canada
Increasing levels of CO2 in the atmosphere will affect ocean chemistry, causing increased acidification (i.e., lower pH) and a reduction in the carbonate ion pool of the global ocean. Differential responses to changes in pH, based on interspecific and ontogenetic variation in physiology and the importance of calcification, could produce changes in structure and diversity at the community level. We conducted a study in a field-deployed flow-through mesocosm system to determine how ocean acidification affects subtidal marine fouling communities. Recruitment plates suspended in the mesocosms were subject to ambient or elevated pH by bubbling in ~600 ppm of CO2 to create a 0.3 pH difference between treatments (n=24). There were significantly fewer mussel recruits (Mytilus trossulus) in the elevated CO2 treatment than in the ambient treatment after nine weeks (40.8 5.2% and 58.1 5.2%, respectively). However, acidification did not influence growth of the mussels that did recruit. Furthermore, recruitment of bryozoans (Mebranipora membranacea) and barnacles (Balanus crenatus), both calcifying members of the community, was not affected by acidification. Our study demonstrates that ocean acidification acts on important ecological processes like recruitment from plankton, which can result in significant shifts in community structure.
Burnett, L.J.*, Sorenson, K.J., Risebrough, R.W.
EGGSHELL THINNING OF CALIFORNIA CONDORS REINTRODUCED TO CENTRAL CALIFORNIA
Ventana Wildlife Society
Monterey County in coastal central California was the site of the first observations by Europeans of California Condors (Gymnogyps californianus) and of the first recorded nesting. A reintroduction program began in 1997; through 2010 eighty four captive-reared condors were released to the wild. We recorded 16 nestings by nine pairs and recovered eggs or shell fragments from 12 nests; shell thinning averaged 34 %, attributed to the DDT compound DDE. Hatching success in central California was 20-40%, significantly lower than 70-80% recorded in southern California. The outer crystalline layer was absent or greatly reduced, similar to the structural changes in thin-shelled condor eggs laid in southern California in the 1960s. Shell thickness was not related to egg size. Weight/water loss during incubation in the wild averaged three times greater than the normal rate associated with successful hatching; the rate of loss increased significantly with decreasing shell thickness. Egg breakage accounted for only two of the 10 failures. Feeding on carcasses of California sea lions (Zalophus californianus), reintroduced condors now occupy a higher level of the food web. Like the other species previously affected, shell thickness is expected to recover as DDE contamination continues to decline.
Burnett, N.P.1,2*, Villarta, K.A.3,4, Helmuth, B.2, Williams, G.A.3,4
Feeding patterns and their implications for energy budgets in tropical limpets
1- University of California, Berkeley, 2- University of South Carolina, 3- Swire Institute of Marine Science, 4- University of Hong Kong
Energy budget models are often used to understand and predict the metabolic responses of species to environmental variation. These models are particularly useful in the intertidal zone, where many species live near lethal limits of stress. The robustness of these models is based on patterns of energy gain and expenditure, but such measurements can be imprecise for species with complex or poorly understood behavior patterns. Although some constraints have been incorporated into behavior models of the keystone grazing limpets (Cellana spp), little is known of their feeding rates and ingestion, remaining a blackbox in the models. Using an accelerometer-based contact microphone, we recorded the feeding patterns (sounds) of Cellana in the field over several tidal cycles. Limpets fed at a rate of 80100 rasps per minute (rpm) while moving up-shore with the flooding tide, became inactive near slack tide, and then fed again at 80100 rpm while moving down-shore with the ebbing tide. These data are consistent with predictions of a model of digestion mechanics that limpets are volume-limited grazers, rather than energy-limited foragers. Field-based foraging measurements can help tailor energy budget models to specific species and improve our ability to forecast energetic consequences of environmental change.
Carlisle, A.B. 1*, Litvin, S.L.1, Madigan, D.J.1, Goldman, K.J.2, Block, B.A.1
USE OF THE CALIFORNIA CURRENT AS A NURSERY AREA BY JUVENILE SALMON SHARKS
1 Hopkins Marine Station of Stanford University, 2 Alaska Department of Fish and Game
The use of nursery areas by elasmobranchs is an important life history strategy that should reduce mortality and increase growth rates. The endothermic salmon shark (Lamna ditropis) is believed to use the California Current System (CCS) as a nursery area, though outside of their occurrence in the CCS, nothing is known about habitat use or trophic ecology of juveniles. Studying how juvenile salmon sharks use the CCS has been limited by access to small sharks; however, young sharks consistently strand along the west coast of North America, providing an opportunity to study these animals using methodologies that do not require live specimens. We used records of stranding events to describe the spatial and temporal pattern of strandings and inform our understanding of distributional patterns. We also collected tissues for stable isotope analysis (SIA) from stranded sharks to examine trophic ecology and habitat use of juvenile sharks in the CCS using SIA, in particular to identify likely prey and habitats used by juvenile sharks. By integrating these two data sources, we are able to describe general patterns of distribution, habitat use, and diet of juvenile sharks in the CCS, and offer some theories about why they might strand.
Carpenter, R.C.*, Johnson, M.D., Moriarty, V.
NITROGEN ADDITION MODULATES THE RESPONSE OF HYDROLITHON ONKODES TO OCEAN ACIDIFICATION
California State University, Northridge
Calcified crustose coralline algae are important primary producers on coral reefs that bind the reef framework together and often serve as settlement cues for coral larvae. The results of previous experiments indicate that rates of calcification of Hydrolithon onkodes are reduced significantly by elevated pCO2, although the magnitude of the response appears to be habitat-dependent. We conducted an experiment in Moorea, French Polynesia to test the hypothesis that nitrogen availability modulates calcification responses of H. onkodes to elevated pCO2. Using a crossed-factor design with two levels of pCO2 (390, 800 atm) and two levels of ammonium concentration (ambient, 10x ambient), coralline algal samples were incubated for two weeks. Samples exposed to elevated ammonium exhibited significantly higher photosynthetic performance regardless of the pCO2 treatment. Rates of net calcification were reduced under elevated pCO2 at ambient ammonium concentrations, but calcification increased significantly with ammonium addition under both pCO2 levels. The mechanism underlying the effect of ammonium enrichment on the calcification response is consistent with the stimulation of photosynthesis by nutrient addition and a close coupling between rates of photosynthesis and calcification. Results suggest that the effects of ocean acidification on calcification will be variable and determined, in part, by habitat-related environmental conditions.
Carr, L.A.*, Vu, I., Bruno, J.F.
WARMING INCREASES GRAZING RATES AND METABOLISM IN A SUBTIDAL HERBIVORE
University of North Carolina at Chapel Hill
Environmental temperature has predictable effects on individual metabolic function, and can partly explain variation in consumption, growth and reproduction. Through this mechanism, temperature can influence the direction and magnitude of species interactions. Rapid ocean temperature changes are pervasive throughout the Galpagos Islands due to upwelling and downwelling of internal waves, ENSO events and seasonality changes; temperatures can drop by 3-9C over a 24 hr period. We tested the hypothesis that there would be less shallow subtidal plant biomass during warm seasons and years because warming increases green urchin (Lytechinus semituberculatus) grazing rates and metabolism. I conducted feeding rate assays in the Galpagos Islands in July 2012. My temperature treatments (14 and 28C) were selected to demonstrate extreme but not uncommon oceanographic conditions around San Cristobal Island, Galpagos Archipelago. We found that both green urchin consumption and metabolism were significantly greater at 28C. Our result that warming increased green urchin metabolic rates provides support for a mechanistic link between environmental temperature and feeding rates. Our findings demonstrate that individual organism response to temperature can change species interactions, especially during warm seasons and years potentially leading to alterations of larger-scale ecological patterns, such as conversion of macroalgal beds to barrens.
MARINE DEBRIS IMPACTS IN THE HAWAIIAN ISLANDS AND NORTH PACIFIC GYRE
Marine Science Department, University of Hawaii, Hilo
Plastic pollution in the marine environment impacts marine ecosystems through smothering, entanglement, and ingestion by invertebrates, fish, turtles, birds, and marine mammals, leaching of plasticizers, concentration of persistent organic pollutants, and the transport of organisms via rafting. Human communities are directly or indirectly affected by reduced tourism or fishing income, increased cost of cleanup, threats to navigation and safety, contamination of food sources, and loss of aesthetic value. These effects are particularly acute in the Hawaiian Archipelago, in part because of its location proximal to the major debris accumulation zone of the North Pacific Gyre. Ill briefly survey a number of ongoing projects in Hawaii including (1) testing how plastic fragments change the physical properties of beach sediment, (2) measuring the input of debris via stormwater runoff from a community on Hawaii Island, (3) tracking the sources and sinks of marine plastic in the islands using drifters and ocean models, and (4) investigating the prevalence of fish and shark attacks on large plastic items. Ill also discuss ongoing work on the macro- and micro-fouling communities of plastic rafts in the North Pacific Gyre and their potential to change pelagic ecosystems and transport invasive species.
Carter, A.L.* Smith, J.E. Deheyn, D.D., Burton, R.S., Price, N.N., Zgliczynski, B.J., Johnson, M.D.
INVASION AND SUCCESSION OF THE CORALLIMORPH RHODACTIS HOWESII AT PALMYRA ATOLL
Scripps Institution of Oceanography
As coral cover declines globally, propermanagement of healthy reefs is becomingincreasingly important. However, even remoteand near pristine reefs are not free fromanthropogenic impacts. On Palmyra Atoll, a National WildlifeRefuge and National Marine Monument, the corallimorphRhodactis howesiiis causingphase-shifts on previously coral dominatedhabitat. This phase-shift was first observedafter the 1991 wreck of a long-lining vessel onthe reef and ten years later the corallimorph hadspread to cover an area greater than 2km2. Although the mechanism of the invasion is largely unknown, one hypothesis isthat iron from the shipwreck added a previouslylimiting nutrient to the waters allowing for the species to spread. We examined the trace metal content of the corallimorphs surrounding Palmyra, focusing specifically on the iron content in their tissues. Our study does not support the iron-enrichment hypothesis, showing no correlation between tissue iron concentration and proximity to the wreck. Additionally, we are looking at the population genetics of the corallimorph to attempt to understand its origin and population dynamics on the reefs. Our results willbe important for improving our understanding ofthis invasive species andadvancing our ability to better manage reefsimpacted byRhodactis howesii.
Castorani, M.C.N.1,2,3*, Hovel, K.A.1, Williams, S.L.2, Baskett, M.L.3
DISTURBANCE FACILITATES COEXISTENCE OF ANTAGONISTIC ECOSYSTEM ENGINEERS
1 – Dept. of Biology and Coastal & Marine Institute Laboratory, San Diego State University, 2 – Bodega Marine Laboratory, University of California, Davis, 3 – Dept. of Environmental Science and Policy, University of California, Davis
Ecological theory predicts that interactions among antagonistic ecosystem engineers can lead to local competitive exclusion, but that disturbance can facilitate broader coexistence. We examined the potential for habitat modification and disturbance to explain the distribution of two benthic ecosystem engineers. Intertidal and shallow subtidal areas in several California estuaries are characterized by alternating patches of eelgrass, Zostera marina, and bioturbated sediments dominated by the burrowing ghost shrimp Neotrypaea californiensis. We first tested whether disturbance to eelgrass could induce shifts to ghost shrimp dominance. Ghost shrimp failed to colonize disturbances to eelgrass patch interiors, even after ten months, but quickly colonized disturbances to edge habitat. To determine the relative competitive abilities of engineers, we transplanted ghost shrimp into eelgrass habitat and vice versa. Transplanted ghost shrimp successfully burrowed beneath eelgrass, but failed to persist over time. By contrast, eelgrass transplants thrived and quickly displaced ghost shrimp locally. We hypothesized that eelgrass physically impedes ghost shrimp burrowing by producing dense belowground structure. To test this prediction, we created structural mimics of eelgrass rhizomes and roots, and then planted these into ghost shrimp habitat. Rhizome-root mimics quickly displaced ghost shrimp, supporting the idea that autogenic ecosystem engineering by eelgrass is an important mechanism determining shrimp distribution. It appears that ghost shrimp can effectively compete only in the very high intertidal, where their bioturbation raises sediment elevation and limits eelgrass to water-logged depressions. We conclude that this nonequilibrium system is maintained by a competition-colonization trade-off. Although eelgrass is competitively superior, disturbance likely permits coexistence of ghost shrimp at the landscape scale by modulating the availability of space.
Catton, C.A1,2, Rogers-Bennett, L.2
ASSESSING THE RECOVERY OF PINK ABALONE (HALIOTIS CORRUGATA) BY INCORPORATING AGGREGATION INTO A MATRIX MODEL
1 – Scripps Institution of Oceanograph, 2 – California Department of Fish and Game
Historically, Point Loma had the highest fishery landings of pink abalone (Haliotis corrugata Wood 1828) along the California coast. The current status of the population in this key location is described using population and aggregation surveys from 2004 to 2007. We develop a size-based matrix model to assess the recovery potential of this low-density population. We incorporate fecundity parameters into the model, modified by empirical nearest-neighbor distance, aggregation size, sex ratio, and size frequency data, to evaluate their influence on the population growth rate. The density of the population was ~170 abalone ha-1. The average aggregation size was ~ 2 abalone, and the average nearest-neighbor distance was greater than 5 meters in all three years. Population growth rates () from the models including aggregation characteristics were 12 18% lower than the models with no aggregation information. A further 12% reduction in occurred between models assuming high and low fertilization success based on the average nearest-neighbor distances (high 1.04 yr-1; low 0.91 yr-1), showing that inclusion of aggregation characteristics has a large impact on population viability analyses. Aggregation characteristics will be important to include when quantifying recovery goals for depleted populations of species susceptible to reproductive Allee Effects.
Cerny-Chipman, E.B.* , Menge, B.A.
TESTING THE IMPACT OF AN INTERTIDAL WHELK PREDATOR ACROSS ENVIRONMENTAL GRADIENTS
Oregon State University
By imposing potentially severe environmental stress on organisms, climate change is predicted to alter species interactions and disrupt ecosystems. Predator-prey interactions can have important effects on community structure, but the strength of these interactions is influenced by abiotic conditions. Environmental stress may alter the impact of a predator on a particular prey species in two ways: 1) by changing the performance of the predator in consuming the prey species, and 2) by changing the preference of the predator for any particular prey. We tested the impact of the intertidal whelk Nucella canaliculata on the prey species Mytilus trossulus in relation to environmental stress. First, we assessed predation rate across gradients of tidal height and wave exposure using experimental caged enclosures at two sites. We found that predation rate differed significantly by site, tidal height, and treatment, but not by exposure level. Second, we surveyed prey choice of whelks in relation to both prey abundance and environmental conditions. Across all conditions, N. canaliculata were observed to feed on 6 prey species.Semibalanus cariosus was the preferred prey species, followed by Mytilus trossulus, and Balanus glandula. Future research will include additional gradients relevant to climate change, including pH and temperature.
Cheng, S.H.1*, Anderson F.E.2, Bergman, A.2, Mahardika G.N.3, Muchlisin, Z.A.4, Thuy D.B.5, Calumpong N.6, Mohamed K.S.7, Sasikumar G.7, Venketesan V.8, Barber P.H.1
PHYLOGENETIC RELATIONSHIPS WITHIN THE BIG-FIN REEF SQUID CRYPTIC SPECIES COMPLEX (SEPIOTEUTHIS CF. LESSONIANA)
1. University of California-Los Angeles, 2. Southern Illinois University,
3. Universitas Udayana, 4. Universitas Syiah Kuala, 5. Nha Trang University,
6. Silliman University, 7. Central Marine Fisheries Research Institute (CMFRI)
The big fin reef squid, Sepioteuthis cf. lessoniana (Lesson 1930) is an important commodity species within artisanal and near-shore fisheries in the Indian and Indo-Pacific regions. While there has been substantial biological, behavioral, morphological and genetic evidence that supports the existence of a species complex within S. cf. lessoniana, these studies have been mostly restricted to the Japanese archipelago. To clarify the extent of cryptic diversity within S. cf. lessoniana, this study examines phylogenetic relationships using mitochondrial genes (cytochrome oxidase c, ribosomal 16s RNA, non-coding region 2) and nuclear genes (rhodopsin) from ~400 individuals throughout the Indian, Indo-Pacific and Pacific Ocean portions of their range. Phylogenetic analyses using maximum likelihood and Bayesian inference identified three distinct evolutionarily significant units with no clear geographic delineations. Two of these ESUs are co-distributed within the sampling range while the third ESU is geographically isolated. This provides not only significant evidence for cryptic lineages within this complex but for possible sympatry of two ESUs. Further morphological and life history data is required to confirm the taxonomic status of these units. This information is extremely useful as a starting point for future studies exploring the evolution of diversity within Sepioteuthis as well as provide species identity information for fisheries management.
Clark, C.T.1, Harvey, J.T.1, Fleming, A.H.2, Calambokidis, J.3
LAST TO LEAVE THE DINNER TABLE: MONTEREY BAY AS IMPORTANT FORAGING HABITAT FOR FEMALE HUMPBACK WHALES LATE IN THE YEAR
1 Moss Landing Marine Labs, 2 Scripps Institution of Oceanography, 3 Cascadia Research
The humpback whale (Megaptera novaeangliae) exhibits the longest migration of any marine mammal, moving between productive high-latitude foraging areas and low-latitude breeding areas where they undergo extensive fasts. Monterey Bay is part of a foraging area used by humpbacks that breed off Mexico and Central America. Though these whales primarily visit this foraging area between May and September, humpbacks are often observed in the nearshore waters of Monterey Bay during October and November. Anecdotal evidence and studies of fish movements indicate these animals likely forage on schooling fish, which move inshore during this period. We collected biopsies (n = 64) from May-November 2011, to learn more about the animals that use this habitat. Carbon and nitrogen stable isotope analysis, genetic sex ID, and progesterone assays were used to determine diet information, sex ratios, and pregnancy status. Stable isotope ratios were consistent with literature values for whales foraging on fish and invertebrates. The sex ratio was roughly even from May to September, and was skewed towards females during October/November. The incidence of pregnancy among these females was unexpectedly low, given that pregnant humpbacks are thought to leave the feeding area last, raising further questions about the migratory patterns of these whales.
Clark, R.*, OConnor, K.
RESULTS OF A NEWLY DEVELOPED RAPID ASSESSMENT TOOL FOR DESCRIBING THE CONDITION AND ECOLOGICAL SERVICES OF CALIFORNIA LAGOONS
Central Coast Wetlands Group, Moss Landing Marine Labs
Californias bar-built estuaries are unique habitats that provide a wide range of ecological services benefitting people and wildlife. Physical processes such as beach bar formation, seasonal flooding and ocean overtopping create variability in surface water elevations and salinity gradients. The presence or absence of these events along with a number of other key attributes will determine the level of services and condition of the site. Management strategies often focus on specific species or environmental objectives, sometimes at the detriment of other aspects of overall condition. The Central Coast Wetlands Group (CCWG) at Moss Landing Marine Labs has been working on an EPA funded project since 2009 to improve statewide understanding of the ecological services this community of individual systems provides through using a recently developed California Rapid Assessment Method (CRAM) module. CCWG staff have visited 32 sites along the entire coastline to run the module and compare the results regionally. The results of the module show how significantly size, location and landuse history have impacted these systems. Using this CRAM module can help resource managers devise better strategies to enhance lagoon ecosystems at a community or even regional level for multiple objectives and evaluate the effectiveness of these implemented actions.
BEHAVIORAL CONSEQUENCES OF SUBLETHAL PESTICIDE EXPOSURE FOR A COMMON ESTUARINE FISH SPECIES, FUNDULUS PARVIPINNIS
Coastal and Marine Institute Laboratory, San Diego State University
Although pesticides are common in marine and estuarine systems, their consequences for the behavior and ecology of resident organisms remain poorly understood. In this study, a common estuarine fish, the California killifish (Fundulus parvipinnis), is a model species to study the behavioral consequences of sublethal pesticide exposure. In a novel approach, I use video data to quantify behaviors of individual fish in different ecological contexts: exploration of an unfamiliar environment, social behavior with conspecifics, and foraging and predation threat. Juvenile F. parvipinnis are exposed to environmentally relevant but sublethal concentrations of chlorpyrifos (a common organophosphate pesticide) for four days prior to behavioral observations. Individuals are then observed in an experimental arena for their activity in an unfamiliar environment, their social behavior, and their willingness to forage in the presence of a model avian predator after a simulated predator attack. Fish exposed to pesticide treatments exhibited multiple altered behaviors which may result in greater predation risk. This confirms the use of behavioral alteration as a sensitive and ecologically relevant biomarker of contaminant exposure. This study will contribute to our understanding of how contaminated estuarine habitats can modify fish behavior with possible ecological consequences.
Conway-Cranos, L. 1, Kiffney, P.1, Banas, N.2, Plummer, M.1, Naman, S.1, Paranjpye, R.1, MacCready, P.2, Bucci. J3, Ruckelshaus, M.4
Stable isotopes and oceanographic modeling reveal terrestrial-marine linkages in Puget Sound
1-NOAA Fisheries, 2-University of Washington, 3-University of New Hampshire, 4-The Natural Capital Project
Shellfish are a key component of nearshore temperate ecosystems and are affected by a suite of natural and anthropogenic processes that originate in both freshwater and marine habitats. Here we investigate the physical and biological extent of freshwater and marine influences to three shellfish growing areas in Puget Sound. Each of these locations supports large, commercially-harvested shellfish populations, but exhibits variation in land use (e.g., forested, agriculture), and near-shore hydrology. We use a fine-scale three dimensional oceanographic circulation model (MoSSea) to determine the extent of physical transport of freshwater to each shellfish growing area. We then examine the isotopic signature (13C and15N) of the Pacific oyster, Crassostrea gigas, collected from all three growing areas to understand the relative contribution of freshwater and marine trophic subsidies to shellfish diets. Potential diet items include phytoplankton, benthic diatoms, intertidal macrophytes (seaweeds and eelgrass), salt marsh plants and upland vegetation. Because shellfish populations depend upon the delivery of uncontaminated water originating from both land and sea, understanding the relative importance of freshwater and marine influences to shellfish beds is an important aspect of sustainable management of watersheds and nearshore ecosystems.
Cordner, E. G.,* Sandin, S. A.
DIET SHIFTS IN HERBIVOROUS CORAL REEF FISHES CORRESPOND TO CHANGES IN FOOD AVAILABILITY ACROSS THE LINE ISLANDS
Scripps Institution of Oceanography, University of California, San Diego
Optimal foraging theory states that diets are the result of numerous trade-offs in foraging strategy. Here we look at how the trade-off between food preference and availability manifests itself in the diets of three herbivorous fish species across the northern Line Islands in the central Pacific. Gut contents of 26 individuals from each species/island combination were identified to functional group and compared to the islands benthic cover. We hypothesize that diet diversity would be higher on those islands that have less food available (due to competition for preferred food). We also expect that if there were a large amount of food available, the composition of fishes diets would remain constant despite shifts in benthic cover (with limited competition). We found that diet diversity was higher in Acanthurus nigricans andCtenochaetus marginatus on islands with more turf cover, while the opposite was found in Stegastes aureus. Herbivorous coral reef fishes are essential in maintaining reef communities, as they feed on algae that are in direct spatial competition with coral. By quantifying how food availability and other bottom-up processes relate to herbivore diets we can better understand how their mediating effects on coral-algal competition may shift with different benthic cover.
Covernton, G.A., Harley, C.D.G
SALINITY STRESS: EFFECTS OF AGE, SOURCE POPULATION, AND CONSTANT VS. VARIABLE SALINITY REGIMES
University of British Columbia
Seasonal increases in the outflow of large rivers following snowmelt can reduce coastal salinity and have important ecological effects on populations of marine organisms. In the Strait of Georgia, British Columbia, seasonal salinity variation may structure populations of the direct developing dog whelk,Nucella lamellosa. In laboratory experiments, we determined that juveniles and adults were both susceptible to low salinity stress, although adults were more tolerant than juveniles, and Nucella from a low salinity site exhibited higher tolerance to low salinity conditions. Whelks subjected to a fluctuating salinity regime to simulate intrusions of more saline water at high tide were able to survive for longer than whelks exposed to constant low salinity. Our laboratory-based findings correspond to population characteristics observed in the field; at sites where salinity fluctuates seasonally and interannually, whelk populations wax and wane with particularly strong differences in the abundance of juveniles. At sites where salinity is consistently high, population sizes and age-class distributions are more stable through time. Our work suggests that in addition to low salinity tolerance, site or age dependent ability to move into deeper, saltier water may play a large role in survival during seasonal peak river outflow.
Cox, C.E.1*, Castillo, K.D.2, Valdivia, A.1, Bruno, J.F. 1
EFFECTIVENESS OF A BAN ON HERBIVOROUS FISH HARVESTING IN BELIZE
1-Department of Biology, University of North Carolina at Chapel Hill, 2 -Department of Marine Sciences, University of North Carolina at Chapel Hill
Caribbean coral reef decline has largely been attributed to overfishing of herbivorous fish species. In 2009, the Belize Fisheries Department implemented a national ban on the capture and possession of herbivorous fish (Scaridae and Acanthuridae) to mitigate algal dominance on the reef. To assess the effectiveness of this approach in restoring herbivorous fish populations and coral assemblages, we measured macroalgal cover, coral cover, coral recruitment, and fish abundance at 16 sites along the Belizean Barrier Reef annually from 2009 to 2012. We found increases in Scaridae and Acanthuridae density at all of the sites but one. However, these changes were not reflected in herbivore biomass because the observed increases in density were detected primarily in small size classes. We detected a trend toward decreased macroalgae cover at 10 sites. However, we have not detected a general increase in coral recruitment. Our results suggest that the ban on herbivorous fish harvesting in Belize is a potentially successful approach to restoring herbivorous fish populations.
Crandall, E.D.1,2,3*, Treml, E.A.4,5, Barber, P.H.1,6
COALESCENT AND BIOPHYSICAL MODELS OF STEPPING-STONE GENE FLOW IN NERITID SNAILS
1 Boston University Marine Program, 2 Southwest Fisheries Science Center, 3 University of California, Santa Cruz, 4 University of Queensland, 5 University of Melbourne, 6 University of California, Los Angeles
Marine species in the Indo-Pacific have ranges that can span thousands of kilometers, yet studies increasingly suggest that mean larval dispersal distances are less than historically assumed. Gene flow across these ranges must therefore rely to some extent on larval dispersal among intermediate stepping-stone populations in combination with long-distance dispersal far beyond the mean of the dispersal kernel. We evaluate the strength of stepping-stone dynamics by employing a spatially explicit biophysical model of larval dispersal in the tropical Pacific to construct hypotheses for dispersal pathways. We evaluate these hypotheses with coalescent models of gene flow among high-island archipelagos in four neritid gastropod species. Two of the species live in the marine intertidal, while the other two are amphidromous, living in fresh water but retaining pelagic dispersal. Dispersal pathways predicted by the biophysical model were strongly favored in 16 of 18 tests against alternate hypotheses. In regions where connectivity was predicted through stepping-stone atolls only accessible to marine species, gene flow estimates between high-island archipelagos were significantly higher in marine species. Moreover, one marine species showed a significant pattern of isolation-by-distance consistent with stepping-stone dynamics. This study couples coalescent and biophysical models to help to shed light on larval dispersal pathways.
Crane, N.L.1,2*, Nelson, P.6,Paddack, M.J.1,7, Bernardi, G.3, Abelson, A.4, Crosman, K.5, Precoda, K.1, Cannon, S.3
Community-based Marine Conservation & Sustainable Fisheries on Ulithi Atoll, Federated States of Micronesia
1-Oceanic Society, 2-Cabrillo College, 3-University of California Santa Cruz, 4- Tel Aviv University, 5-University of Michigan, 6-CFR-West, 7-Santa Barbara City College
Coral reefs around the world are suffering from multiple stressors, affecting ecological integrity of coral systems, and the livelihoods of people who rely on them. This project addresses the need to work with small autonomously governed communities to strengthen their capacity to manage their reefs and marine resources during a time of rapid ecological change. By invitation of the Chiefs of Falalop, we visited Ulithi Atoll, Micronesia, in summer 2012 to help create a plan for sustainable marine resource use. We incorporated social science (interviews, community meetings) and quantitative ecological assessments (reef surveys, catch analysis) to identify trends and concerns. A critical part of our approach is to empower and engage the community in data collection and decision-making. We trained people in catch analysis and shallow reef habitat surveys, and held meetings to provide background information on reef ecology, share initial findings and answer questions. At the end of this initial visit, we provided recommendations but asked them to create a plan based on their cultural and decision making/enforcement framework. Falalop implemented a LMMA within weeks of our departure. As a result of our work here and additional regional meetings, we have been asked to help develop an atoll-wide plan.
Daugherty, M.J.*, Brewer, L.H., Johnston, L.A., Tomanek, L., Wendt, D.E.
REARING TEMPERATURE AFFECTS THE EXPRESSION OF PROTEINS IN BARNACLE ADHESIVE
Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo
Barnacles are dominant hard-fouling organisms in marine waters, attaching to substrates by secreting a proteinaceous adhesive. Understanding the chemical composition of this multi-protein underwater adhesive and how it is affected by environmental variables, such as oceanic temperatures, is central to developing non-toxic solutions to control biofouling. Previous experiments in our lab have shown an inverse relationship between critical removal stress (CRS) and temperature at which barnacles were reared. Further investigations showed that this correlation is not attributed to differences in physical properties such as barnacle size or short-term changes in the viscosity of adhesive due to removal temperature. Therefore, it seems the observed effects may be influenced by a physiological response to temperature during initial growth and development. We hypothesized that rearing temperature affects the expression of proteins found in the adhesive matrix. To elucidate the underlying mechanisms responsible for the temperature effect, we analyzed uncured barnacle adhesive using 2D-E proteomics. Through this analysis, we have 1) detected differences in protein expression at two experimental temperatures (15C and 25C) and 2) identified proteins consistent with a proposed model that suggests the curing process of barnacle adhesive may be analogous to the process of wound healing in animals.
ESTABLISHMENT AND PERSISTENCE OF MACROALGAL PHASE SHIFTS
Department of Ecology Evolution and Marine Biology, University of California Santa Barbara
Coral reefs are currently threatened by an increasing frequency and magnitude of natural and anthropogenic perturbations, which can facilitate community shifts from coral to macroalgae. Such shifts have received considerable attention since macroalgae are known to inhibit coral recruitment, and thus hinder or prevent reef recovery. I investigated potential mechanisms that permit the establishment and persistence of macroalgae using field experiments and herbivore assays in the lagoons of Moorea, French Polynesia. Using feeding assays with different sized individuals, I tested the hypothesis that size-related vulnerability to herbivory may facilitate establishment of Turbinaria ornata. Results suggest that consumption of Turbinaria generally decreases with size, which can lead to the establishment ofTurbinaria if the alga survives the brief period when it is especially vulnerable. Once established, a phase shift may be reinforced by additional positive feedback mechanisms. I tested whether vulnerableTurbinaria recruits experience a refuge from herbivory when they are associated with unpalatable adults. This mechanism would promote persistence of a Turbinaria population once mature individuals become established. My results show that survival of recruits was higher when they were associated withTurbinaria adults than when alone. These feedbacks may limit the capacity of herbivores to reverse a phase shift.
Dawson, M.N1*, Hays, C.G.1,2, Grosberg, R.K.3, Raimondi, P.T.4
DISPERSAL POTENTIAL AND POPULATION GENETIC STRUCTURE OF SYNCHRONOUSLY DIVERGING CO-DISTRIBUTED MARINE INTERTIDAL TAXA
1 – University of California Merced, 2 – Keene State College, 3 – University of California Davis, 4 – University of California Santa Cruz
Life-history traits related to dispersal, such as pelagic duration (PD), should affect the frequency and spatial scale of migration and thus influence population genetic structure. However, recent global analyses have concluded that PD is poorly correlated with marine population genetic structure. Here, we identify and compare genetic structure in synchronously diverging co-distributed (SDC) species, using standardized analyses of eastern North Pacific rocky intertidal invertebrates and a macrophyte. We test two hypotheses: (H0) that species with similar dispersal potential have similar population genetic structure and (H1) that species with higher dispersal potential have lower population genetic differentiation. We find that differences in census population size (Nc), fecundity (F), and PD are sufficient to explain measured differences in population genetic structure (FST) between SDC species.
Dayton, PK1, Jarrell, S. 1, Kim, S. 2, Robilliard, G.A.3, Oliver, J.S.2, Barry, J.P.4, Thurber, A. 5
PERSPECTIVES OF 100 YEARS OF SPONGE ECOLOGY AT MCMURDO SOUND, ANTARCTICA
1- Scripps Institute of Oceanography, 2 Moss Landing Marine Laboratories, 3 Cardno ENTRIX, 4 Monterey Bay Aquarium Research Institute, 5 Oregon State University
The early British explorers did a thorough job collecting most of the large animals in the McMurdo Sound region. The next serious science was done by a small group of remarkable Stanford students who laid the foundation for all subsequent ecology at McMurdo Sound. Our program started in the mid-1960s focusing on the ecology of the sponge community. The sponges we studied had virtually no recruitment nor growth through 1977, however two species, especially Homaxinella balfourensis, had a fast recruitment and growth, but with these exceptions slow growth rates continued through 1989 and probably through 1998. An array of artificial structures placed between 1960 and 1974 also showed virtually no recruitment or growth of sponges through 1998 with the exception of Homaxinella. In 2010 we revisited many of the initial sampling sites and underwater structures and found surprisingly high recruitment and growth of more than 30 species of sponges. The most dramatic change was a 1950s era gangplank that had been observed to be clean through the 1960s, was covered by H. balfourensis through the 1970s, was cleared by anchor ice in the 1980s and remained clean through the 1990s, and in 2004 was photographed with a dense settlement of Anoxycalyx joubini. By 2010 nineteen individuals dominated most of the space and together were estimated over 560 Kgm.
Demes, K.W.1*, Harley, C.D.G. 1, Anderson, L.M. 1, Carrington, E. 2
Shifts in morphological and mechanical traits compensate for performance costs of reproduction in a wave-swept seaweed
1 University of British Columbia, 2 Friday Harbor Laboratories
In addition to metabolic costs associated with reproduction, morphological and mechanical changes accompanying reproductive effort can affect an organisms performance. We investigated mechanical and morphological changes associated with reproduction in the winged kelp, Alaria marginata. Compared to non-reproductive sporophylls, reproductive sporophylls were longer, were similar in width, and had greater surface area. Reproductive sporopylls were also thicker and less ruffled. Tissue extensibility and breaking stress were not different in reproductive vs. vegetative sporophylls. However, reproductive tissue exhibited greater tensile stiffness, flexural stiffness, and force to break. Reproductive sporophylls experienced greater drag (despite decreased flapping) than did vegetative sporophylls, but did not experience greater size-specific drag. Tissues cut into experimental blades of the same size and shape experienced greater drag when cut from reproductive tissue suggesting that the change in shape associated with the onset of reproduction ameliorates the cost of increased tissue stiffness. Nonetheless, increased blade breaking force in reproductive individuals resulted in elevated blade safety factors (breaking force/drag experienced) in reproductive compared to non-reproductive sporophylls. In sum, changes in blade ruffliness and strength associated with the onset of reproduction in Alaria marginataameliorate the concomitant mechanical costs of decreased flexibility and increased size.
Dobkowski, K.A.1*, Hamel, K.M.2, Waaland, J.R.1
KELP CRABS (PUGETTIA PRODUCTA) EAT KELP (AND LOTS OF OTHER THINGS)
1 University of Washington, 2 University of Hawaii – Manoa
Marine herbivores can play a major role in structuring temperate nearshore, subtidal, kelp-dominated communities. To assess the potential of crabs to exert top-down control on kelp bed species, we quantified feeding preferences of kelp crabs (Pugettia producta) on a range of prey items, including macroalgae and snails. This research addressed four questions: does P. producta eat kelp; is bull kelp (Nereocystis luetkeana) preferred to other macroalgal species; does algal morphology play a role in food preference; and is N. luetkeana preferred to an invertebrate food source? Our results indicate that P. producta eats kelp and, in tissue feeding experiments, preferred N. luetkeana to two other local kelp species. Non-kelp macroalgae as well as kelp species were evaluated in two additional feeding preference assays, one using fresh tissue and the other using artificial food pellets. Results indicated that P. productamay prefer Ulva spp. to kelp in both cases. Results of Y-maze feeding trials indicate that P. productashows no significant preference between kelp and snails, although some behavioral differences between individual crabs were observed. Overall, we documented generalist feeding by kelp crabs, which could be scaled up to community-level impact based on body size and density.
Donovan, M.K.1,2*, Friedlander, A.M2, Jackson J.B.C.1,3, Lam, V.1, Cramer, K.1,3, Hooten, A.1
SPATIAL AND TEMPORAL PATTERNS IN FISH ASSEMBLAGE STRUCTURE IN THE CARIBBEAN
1- International Union for the Conservation of Nature, 2- US Geological Survey, Hawaii Cooperative Fishery Research Unit, University of Hawaii, 3- Smithsonian Tropical Research Institute
The degradation of reefs worldwide continues to accelerate, and there are increasing demands for a more systematically rigorous quantitative assessment of the status and trends of reef ecosystems at a global scale. To that end, the IUCN Coral Reef Resilience Project is compiling high quality quantitative survey data from coral reefs across the Caribbean to examine spatial and temporal patterns in coral reef community structure throughout the region. A total of 75 fish data sets from 26 countries spanning 38 years have been obtained to date. Various fish assemblage metrics were analyzed among locations to evaluate to what degree various local stressors can explain different trajectories in space and time. Species-specific trends in size, numerical density, and biomass were analyzed to reveal that fish biomass is now low Caribbean-wide compared to historical estimates, but that different trajectories among locations cannot be explained by conclusions drawn at the regional scale. Fish biomass is extremely low at most sites throughout the region, typically less than 50 gm-2, which is < 75% of biomass in the few areas with effective protection such as Gardens of the Queen in Cuba. With this approach we aim to document changes in ecosystem structure that will provide clues to the relative importance of different processes driving reef change and inform future management and conservation.
Dudgeon, S. R. 1*, Rhile, E. C. 2, Petraitis, P. S.3
TEMPORAL VARIABILITY IN MUSSEL MORTALITY IN CLEARINGS AND UNDER CANOPIES
California State University Northridge 1, Cheverus High School, Portland, ME2, University of Pennsylvania, Philadelphia, PA3
In the Gulf of Maine, populations of the mussel, Mytilus edulis, can be controlled by the foraging activities of dogwhelks and green crabs. Consumer control of mussels during succession in sheltered bays depends on patch size; predation under, or near, canopies being greater than in large clearings. Clearings of 1, 2, 4 and 8 m in diameter and uncleared controls were established in 1996, half of which were cleared again in 2010-2011. The remaining plots were not manipulated. We have assayed the mortality of mussels in plots in 9 years between 1996 and 2012. Predation on mussels by dogwhelks and crabs varies tremendously between years associated with closure of patches. Predation on mussels also temporally varied among clearing sizes, sites and bays. In contrast, mortality due to all other sources varied much less in time, in space and among treatments. Variability in predation on mussels in space and time has greatly exceeded variability in mortality of mussels from all other sources. These results imply that contingent patterns of succession and the formation of alternative community states can be driven by spatial, and especially, temporal variability in consumer control by predators coupled with variable recruitment of their competitively dominant prey.
Dunn, R. P.1*, Eggleston, D. B.1, Lindquist, N.2
IMPACTS OF SUBSTRATE MATERIAL ON OYSTER RESTORATION ACROSS A SALINITY GRADIENT
1-Center for Marine Sciences and Technology, North Carolina State University; 2- UNC-Institute of Marine Sciences
Restored oyster reefs in high-salinity areas of Pamlico Sound, North Carolina have recently experienced population crashes, potentially brought on by Clionid boring sponge infestation of oyster shells and the limestone marl reef substrate. The composition and porosity of limestone marl may make it particularly vulnerable to bio-erosion by sponges, so alternative substrates must be assessed for use in future reef building efforts. In this study, combined lab and field work is being used to investigate the efficacy of four reef substrate materials: oyster shell, limestone marl, granite, and concrete, from substrate-specific rates of oyster settlement, growth, and mortality, as well as boring sponge growth. Larval oyster settlement in the laboratory was highest on oyster shell and marl with no difference between them, second highest on concrete, and lowest on granite with few settlers. Substrate materials were also deployed in two estuaries where differences in sponge growth were observed, with oyster shell and marl being more susceptible to sponge colonization than concrete or granite. There were also positive correlations between oyster mortality and salinity, as well as boring sponge growth and salinity. This work suggests the use of non-calcium carbonate-based materials for future oyster reef construction in high salinity locations.
DECADAL-SCALE CHANGES IN THE COMMUNITY STRUCTURE OF CORAL REEFS IN ST. JOHN, US VIRGIN ISLANDS
Department of Biology, California State University Northridge
Most coral reefs differ from those described by ecologists in the 1950s, and reports of degraded reefs and hypotheses regarding the implications of the changes abound. Unfortunately, decadal-scale studies of value in testing these hypotheses are rare. In this study, 25 y of time-series analyses from three habitats in St. John reveal changes in coral community structure that are spatially and temporally heterogeneous, only loosely coupled with local disturbances, and equivocal in terms of the future than can be predicted from the past. In a near-shore habitat at 7-9 m depth, coral cover remained ~4% between 1992 and 2011, and variation in community structure was driven mostly by Agaricia; in a Montastraea habitat at 9-m depth, coral cover declined from 45% (1987) to 7% (2011) and varied among decades; in a secondMontastraea habitat at 14-m depth, coral cover increased from 32% (1987) to 49% (2002) and then declined to 29% (2011). The density of juvenile corals also changed over time, with genera responding in dissimilar ways to time in patterns suggestive of supply-side effects. The reefs of St. John have changed markedly since 1987, but the present results suggest these coral communities may now persist in a degraded state.
Edwards, C.B.1, Friedlander, A.M. 2, Green, A.G. 3, Hardt, M.J. 4, Sala, E. 5, Sweatman, H.P. 6, Williams, I.D. 7, Zgliczynski, B. 1, Sandin, S.A. 1, Smith, J.E 1
GLOBAL ASSESSMENT OF THE STATUS OF CORAL REEF HERBIVOROUS FISHES: EVIDENCE FOR FISHING EFFECTS
1 – Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, La Jolla, CA, 92093-0202, USA, 2 – Us Geological Survey, Hawaii Cooperative Fishery Research Unit, University of Hawaii Manoa, Honolulu, HI, USA, 3 – The Nature Conservancy, Brisbane, QLD 4101, Australia, 4 – OceanInk, Kamuela, Hawaii, USA, 5 – National Geographic Society, Washington DC, 6 – Australian Institute of Marine Science, TMC, Townsville, QLD 4810, Australia, 7 – National Oceanic and Atmospheric Administration (NOAA), Pacific Islands Fisheries Science Center, Coral Reef Ecosystem Division, Honolulu, HI, USA
Coral reef herbivores provide important ecological services by regulating competitive interactions between reef building corals and fleshy algae, yet little is known about their global status. Here we perform the first global synthesis of coral reef herbivorous fishes with data from peer-reviewed sources and scientific monitoring programs. Our results show that herbivorous fish biomass at protected or remote sites is more than double that at fisheries accessible sites (56.4 and 20.5 g m-2, respectively) and is independent of regional effects. Analysis by feeding sub-guilds shows that fishing disproportionately reduces the biomass of larger-bodied scraper/excavator and browser groups. Loss of larger bodied herbivores likely alters the overall effectiveness of these fish to regulate algal abundance on reefs and suggests that restoration strategies should not simply consider herbivores as a single group but maintain proper feeding guilds ratios. This is the first global assessment of coral reef herbivore populations and includes many remote locations that may be useful for developing management targets globally. As herbivores play an important role in maintaining the balance between algal and coral cover, these results have significant implications for the development of management strategies to improve the resilience and restoration of the worlds coral reefs.
Edwards, M.S.1*, Konar, B.K.2
A comparison of dragon kelp Fecundity in urchin barrens and nearby kelp beds throughout the Aleutian Archipelago
1 San Diego State University, 2 University of Alaska Fairbanks
The Aleutian Archipelago coastal ecosystem has undergone a dramatic change in community composition during the past two decades. Following the removal of ~99% of the sea otters from the ecosystem, changes to the benthic communities resulted in widespread losses to most of the regions kelp beds and corresponding increases in the prevalence of urchin barrens. We examined patterns of sporophyte fecundity in the dominant canopy-forming kelp, Eualaria fistulosa, in both urchin barrens and in nearby kelp beds at seven Aleutian Islands spanning a range of 800 km. We found that the average weight of E. fistulosa sporophyll bundles was significantly greater on sporophytes occurring in the urchin barrens than in the nearby kelp beds. Further, the average number of zoospores released per cm2 of sporophyll area was also significantly greater in individuals from the urchin barrens than the nearby kelp beds. When these two metrics were combined, our results suggest that individual E. fistulosa sporophytes occurring in the urchin barrens may produce as many as three times more zoospores than sporophytes occurring in the nearby kelp beds, and thus they may contribute disproportionately to the following years sporophyte recruitment in both urchin barrens and the adjacent kelp beds.
Eernisse, D.J.1*, Draeger, A.2, and E.M. Pilgrim3
JAPANESE TSUNAMI CHITONS AND LIMPETS WASHED UP ON AN OREGON BEACH
1 Cal State Fullerton, 2 Kensington, CA, 3 Ecol. Exposure Res. Div., US EPA, Cincinnati, OH
On March 11, 2011, a monstrous Japanese tsunami swept a vast plume of buoyant objects out to sea, including some nearshore floating structures already covered with attached biota. The potential for this debris plume to deliver exotic marine species to the West Coast was demonstrated dramatically when a 20m x 5.7m floating dock washed ashore near Newport, Oregon. Its attached coastal Japanese biota had survived a more than 14-month journey across the Pacific. Such arriving debris-plume objects triggered an ongoing response from government agencies and scientists concerned with the plumes continuing potential to deliver invasive species. We participated in assessing the Newport docks biota by identifying three chitons and four limpets. The chitons are Mopalia seta Jakovleva, 1952, based on girdle setae, valve sculpturing, and 16S/COI mitochondrial sequences. The docks origin, Misawa on northeastern Honshu Island, produces a slight southern range extension for M. seta. One limpet specimen is Nipponacmea habei(Saski & Okutani, 1994) based on morphology and a close sequence match toGenBankN. habei sequences. The other limpets are likely a species still unrepresented in GenBank, tentatively identified as the Lottiasp. figured by T. Sasaki (2000) in the T. Okutani edited Marine Mollusks in Japan.
Elahi, R.1,2* , Dwyer, T.1, Turner, K.R.1,2, Sebens, K.P.1,2
FOUR DECADES, FEW CHANGES: ARE SUBTIDAL ROCK WALLS REFUGIA?
1 Friday Harbor Laboratories, 2 University of Washington, Department of Biology
Long-term datasets provide a baseline for evaluating temporal variation in biodiversity and are critical for distinguishing between natural and anthropogenic mechanisms of change. In this study, we tested the hypothesis that epilithic communities on subtidal rock walls in the San Juan Islands, WA, USA, between 1969 1974 were unique relative to rock walls between 2006 2011. Despite a 0.9C rise in temperature and increased protection of sea urchins and bottomfishes over the intervening four decades, univariate and multivariate analyses suggest limited differences between historic and modern communities. Historic communities were more even, and characterized by a high percent cover of bare rock and noncalcified encrusting algae, suggestive of urchin grazing. Despite the initiation of urchin no-take restrictions in 1984, our data indicate that urchin densities in the 1970s were comparable to contemporary levels. Although we detected subtle variation in the communities driven primarily by less abundant taxa (e.g., brachiopods, pedal sea cucumbers), it is difficult to ascribe these differences to temporal, rather than spatial, variation. We suggest that subtidal rock walls may serve as potential refugia from biodiversity loss, and emphasize the need for long-term ecological monitoring with consistent methodology.
MARINE CONSERVATION IN THE MEDIA: AN AUDIT OF VALUES-BASED CAMPAIGNS IN NONPROFIT
Simon Fraser University
Nonprofit organizations, as a representative of civil society as a whole, are often responsible for communicating science to the public and requesting action from them a task that is highly dependent on the efficiency of the strategies they employ. A wide body of environmental communications literature formerly focused on an information deficit approach, stating that the more information various publics are exposed to, the more likely it is to have an impact on them and the more likely these publics are to take action (e.g., sign petitions, volunteer, etc.). However, new studies point more conclusively to a values-based theory that takes into account the irrational behaviour of humans. Stating that publics are more likely to act based on their deep frames, values, and overall beliefs, work has been done to incorporate this into the realm of nonprofit outreach campaigns (Crompton, 2010). Through Cromptons principles and recommendations on switching towards values-based campaigns, my research performs an audit on if/how marine conservation nonprofit organizations are completing this transition from information-loading strategies to ones that invoke public values. This research also investigates the role of nonprofit groups as interface organizations those that take information from the science community and relay such to the public. By assessing the role scientists have in these campaigns, and the (im)balance between science and advocacy that scientists achieve, a holistic picture of nonprofit campaigns and their effectiveness will begin to surface.
Ewers, C.J.*, Moline, M.A., Wendt, D.E.
DEVELOPING PHOTOSYNTHESIS-IRRADIANCE CURVES TO ASSESS EELGRASS, ZOSTERA MARINA, PRODUCTIVITY IN A CHANGING CLIMATE
California Polytechnic State University, San Luis Obispo
Seagrasses are well-known for the important ecological roles they play worldwide; unfortunately, the severe rate of decline observed in seagrasses this century is expected to accelerate with climate change. This study examines the effects of climate change, specifically changes in light and temperature, on eelgrass (Zostera marina) productivity. Whole ramets, collected from three beds in Morro Bay, California, were used to develop photosynthesis-irradiance (P-I) curves from 10-20C. Daily energy requirements were calculated from respiration rates and used to determine critical irradiance thresholds. Many studies suggest that rising temperatures will benefit seagrasses by increasing the gross light-saturated rate of photosynthesis (Pmax); however, our results indicate there is a concomitant increase in respiration rate, resulting in no net change in Pmax with increasing temperatures. Further, P-I curve initial slopes decreased, indicating eelgrass is less productive at higher temperatures when light is limited. Bed location had significant effects on P-I curves. Our data show the mid-bay bed is most vulnerable to additional stress: it has the lowest net Pmax coupled with the highest average respiration rate and showed evidence of photoacclimation. Superlative eelgrass conservation will require consideration of natural variation across beds to create strategized restoration efforts, even in small geographic regions.
Fabina, N.S.1*, Putnam, H.M.2, Franklin, E.C.2, Stat, M.3, Gates, R.D.2
THE STABILITY OF CORAL-SYMBIODINIUM COMMUNITIES IS DEPENDENT ON BIOLOGICAL ASSUMPTIONS
1 – University of California, Davis, 2 – Hawaii Institute of Marine Biology, Kaneohe Bay, 3 – University of Western Australia, Perth
Most reef-building corals in the order Scleractinia depend on endosymbiotic algae in the genusSymbiodinium for energy and survival. Significant levels of taxonomic diversity in both partners result in numerous coral-Symbiodinium associations with unique functional characteristics. To highlight the importance of ongoing coral research questions, we characterize coral-Symbiodinium community stability by using a simple network theory tool. First, we create interaction networks using a dataset of associations between coral species and symbiont types. Second, we impose simulated species extinctions and measure community responses. Community stability is strongly dependent on the order of species removal, the chosen measure of stability, and the functional importance and environmental tolerance of symbiont partners. In particular, coral-Symbiodinium communities are less stable if species with few associations are also environmentally sensitive, which previous studies suggest is likely the case. Furthermore, communities appear to be more stable if association potential is prioritized over species diversity. Finally, communities are much more stable if subdominant or rare Symbiodinium are functionally meaningful, and much less stable if there are no adequate substitutes to dominant symbionts. Our results demonstrate the importance of incorporating accurate ecological and biological information into reef resilience projections.
Farris, M.R.*, Ahr, B.J., Lowe, C.G.
MOVEMENT PATTERNS AND BEHAVIOR OF WHITE CROAKER (Genyonemus lineatus) IN THE LOS ANGELES AND LONG BEACH HARBORS
California State University, Long Beach
Acoustic telemetry techniques are used to gain insight into the short-term and long-term movements of white croaker (Genyonemus lineatus) in the Los Angeles (LA) and Long Beach (LB) Harbors. To characterize longer-term, broader scale movements, the harbors were divided into four areas; inner LA, outer LA, inner LB, and outer LB, and 25 individuals were tagged in each section. Their movements between areas were monitored by 12 automated acoustic receivers. Short-term, fine-scale movements are studied using active acoustic tracking, where fish are followed over multiple 24 hr periods. Individuals actively tracked exhibited an average daily area use of 111,964 m2 101,284 m2 ( SD). No significant difference has been observed in area use during day time (81,223 m2 112,754m2) and night time (54,686 m2 98,607 m2) (p = 0.093). Data from this study indicate that an area in the inner LA Harbor, known as the Consolidated Slip, may be an area of particular importance to G. lineatus within the harbor. Fish tagged in this area exhibit higher site fidelity than fish in other areas of the harbor. The Consolidated Slip is also known to contain the highest concentrations of DDT and PCBs in sediments within the Harbor.
Ferrier, G.A.1 Zimmer, R.K.1,2
BIOMINERALIZATION, EXPLOITATION, AND THE SENSORY BASIS OF KEYSTONE PREDATION
1-University of California Los Angeles, 2-Moreton Bay Research Station, University of Queensland
On rocky wave-swept shores, seastars drive species abundances and distributions through selective predation on mussels, a dominant space competitor. This keystone interaction is established to a large degree by behaviorally mediated processes that rely on sensory inputs. Here, we isolated, purified, and identified the complete amino acid sequence (244 residues; mol mass = 27.8 kDa) of a glycoprotein, KEYSTONEin, requisite to mussel shell mineralization. The molecule is synthesized naturally by cells in mantle tissue and excreted into the extrapallial fluid before localization in the zone of new growth along the shell margin. We embedded purified KEYSTONEin in a gel polymer at native tissue concentrations to create faux prey. Seastars did not distinguish between faux prey and live mussels. They fed equally, without preference, on both prey types in laboratory and field experiments. Whereas mussels use KEYSTONEin to produce shell material that serves effectively as a morphological defense against a diffuse network of disturbances, seastars have evolved offensive weaponry and sensory mechanisms for eavesdropping on this compound as a seminal feeding cue. Finally, KEYSTONEin recognition is not limited to seastars. Rather, many intertidal predators, including whelks and crabs, exploit this protein as phagostimulant.
Flanagan, A.M.*, Cerrato, R.M.
A QUANTITATIVE ASSESSMENT OF A CLASSIC SEDIMENT CLASSIFICATION SCHEME FOR CHARACTERIZING BENTHIC MARINE SYSTEMS
School of Marine and Atmospheric Sciences, Stony Brook University
One challenge in ecological classification of benthic marine habitats involves the identification of animal-sediment relationships. Two primary classification schemes have been proposed for and are being implemented in New York (NY) waters: one proposed by Auster et al. (2009) for the Long Island Sound region and the Coastal and Marine Ecological Classification Standard (CMECS) developed by the Federal Geographic Data Committee (FGDC). Although these classification approaches are considerably different from one another in terms of their structure and the categories they contain, both employ the Folk (1974) classification system to categorize sediment type by grain size. Folks classification system consists of 25 sediment classes, but it is unclear which or how many of these classes correspond to benthic community structure. The purpose of this study was to evaluate the Folk (1974) scheme using multivariate regression tree (MRT) analyses of sediment and faunal data from six locations in NY waters. We anticipate a simpler sediment classification system (i.e. one with fewer categories) will explain an equivalent fraction of benthic community variation while minimizing the risk of overfitting the data and subsequently reducing explanatory power.
STABLE ISOTOPE FRACTIONATION TRACKS RECOVERY FROM BIOMASS LOSS IN MACROCYSTIS PYRIFERA
Moss Landing Marine Laboratories
The large, complex morphology of giant kelp, Macrocystis pyrifera, allows for dynamic movement of internal resources to support different growth mechanisms. This ability to translocate resources plays an important role in facilitating recovery from biomass loss through the production of new fronds. Historically, total percent carbon and nitrogen has been used as the primary proxy for physiological condition and resource availability in marine macrophytes. However, recent evidence from a biomass removal experiment has shown stable isotope fractionation to track recovery more effectively inMacrocystis. To further investigate the physiological drivers behind these shifts in isotopic composition a biomass removal experiment was conducted using a regression model; fronds were removed from adultMacrocystis sporophytes to create a series of 11 individuals with 0 – 11 intact canopy fronds. Tissue samples were collected from the primary growth tissues: mature canopy blades, juvenile blades, and frond initials. Shifts in isotopic composition among these tissue types suggest changes in physiological processes and resource allocation in response to increased biomass loss. These results highlight the potential for stable isotopic analysis to provide new insights to Macrocystis physiology and serve as a valuable tool to assess recovery from disturbance within this species.
Freedman, R., C. Whitcraft, B. Allen, Lowe, C.
MOVEMENTS OF ESTUARINE PREDATORY FISHES BETWEEN TWO DISCRETE RESTORED ESTUARIES
California State University Long Beach
Using acoustic telemetry, we assessed connectivity potential, habitat preference, and homing behavior of five coastal predator fishes between two restored estuaries. Juvenile California halibut, Paralichthys californicus (n=30), spotted bay bass, Paralabrax maculatofasciatus (n=9), gray smoothhounds, Mustelus californicus (n=30), shovelnose guitarfish, Rhinobatus productus (n=6), and leopard sharks, Triakis semifasciata (n=5) were caught at Bolsa Chica Full Tidal Basin and Huntington Beach Wetlands, fitted with acoustic transmitters and translocated between study sites (approximately a 10 km distance). Residence times after translocation have not revealed a preference for either estuary and all species except P. maculatofasciatus have individuals that moved between study sites. For fish that utilized both estuaries, the residence time in the translocation site significantly differed by species; however, the time spent moving between study sites, or homing time, did not. Fishes spend an average of 1435 days homing; however, 66% made the journey in 3 days or less. Rhinobatos productus, T. semifasciata, M. californicus, and P. californicus movements are evidence of connectivity between estuaries at this distance and the time spent after translocation may imply habitat selection. The translocation residency exhibited by P. maculatofasciatus possibly indicates that individuals remain in the estuary where they first recruit.
Freiwald, J. *, Wehrenberg, M. L., Wisniewski, C. J.
CHANGES IN FISH ABUNDANCES ON ROCKY REEFS SINCE THE 1970S COMPARISON OF HISTORIC DATA TO REEF CHECK CALIFORNIA SURVEYS
Reef Check California
Over the last forty years the biological communities on Californias rocky reefs have changed and declines of many species have been documented. Nevertheless few, if any, continuous datasets exist that track the abundances of nearshore rocky reef fish species along Californias coast over this time period. To test if rocky reef fish populations overall have declined in the past forty years, we analyzed underwater fish survey data from studies conducted in the 1970s and compared the historic fish densities to densities from Reef Check California surveys conducted on the same reefs between 2006 and 2011. Data are spanning three bio-geographic regions: central California, southern Californias transition zone and Californian Province. For most species, densities between 2006 and 2011 were much lower than in historic studies at all locations. Differences can be attributed to the natural variably of local fish populations, oceanic regime shifts and overfishing. Analyses like these are essential for establishing baselines for management and conservations efforts. Current management approaches focusing on ecosystem health rely on comparison to historic states of the system for health assessments. Therefore, without established historic abundances of many of the community members for comparison it is difficult to assess the current health of ecosystems.
Furby, K., Smith, J., Sandin, S.
CORAL MORTALITY AND RECOVERY AFTER A BLEACHING EVENT ON PALMYRA ATOLL
Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego
Remote Pacific reefs are subjected to limited local stressors, creating ideal environments for studying coral response to climate change without extraneous compounding factors. Due to an El Nio Southern Oscillation (ENSO) event, increased ocean temperatures at Palmyra Atoll in the US Line Islands in 2009 resulted in a bleaching event of some coral taxa (e.g. Porites, Pocillopora). High mortality (both partial and complete) was observed on select tax between 2009 and 2010. From 2010 to 2011 lower mortality rates were recorded, with the addition of modest recovery of the population. The majority of recovery was attributed to new coral settlement, however re-growth of established colonies played an important role in reclaiming substrate for the species. New coral settlement was exactly uniform across surveys, suggesting little impact of thermal anomalies on settlement. This study is unique in its comparisons between the relative contributions of re-growth of established colonies to settlement of new corals during population recovery of remote Pacific reef.
Gabara, S.S.1*, Steller, D.L.1, Finney, B.P.2
ENERGY FLOW THROUGH A RHODOLITH BED AT SANTA CATALINA ISLAND, CA
1 – Moss Landing Marine Laboratories, San Jose State University, 2 – Department of Biological Sciences and Geosciences, Idaho State University
Identifying the trophic base of food webs is fundamental to understanding ecosystems. Energy flux through marine ecosystems has been widely studied in coral reefs, seagrass beds, rocky reef habitats, and kelp forests. Rhodolith beds, consisting of free-living coralline algal nodules and associated organisms, are understudied but may be considered structurally similar to laminarian holdfasts as they provide habitat and catch and preserve Particulate Organic Matter (POM). The goal of this study was to determine the origin and path of primary production through California coastal rhodolith beds at Santa Catalina Island. Using carbon and nitrogen stable isotopes (13C and 15N) from offshore and onshore phytoplankton, common onshore algae, and invertebrates in a rhodolith bed, the food web appears to be subsidized by adjacent macroalgal production of giant kelp (Macrocystis pyrifera). Adjacent giant kelp beds produce fresh blade and detrital drift tissue, which contributed to the assimilated diet of herbivorous invertebrates along with common epiphytic macroalgae on rhodoliths and plankton. Giant kelp detritus may contribute to POM that accumulates within rhodolith thalli, along with other brown algae and plankton. Relative to Atlantic rhodolith beds, rhodolith beds off Catalina are less reliant on plankton and include another source of primary production, fresh and detrital tissue from adjacent kelp beds.
Galloway, A.W.E.1,2*, Lowe, A.T. 2, Duggins, D.O.2
Trophic mysteries of the deep: differences in invertebrate consumer biomarkers across depths
1 University of Washington School of Aquatic and Fishery Sciences, 2 Friday Harbor Laboratories
Nearshore marine primary production is constrained to the top 20 m in the temperate waters of the NE Pacific. Benthic consumers (e.g., direct herbivores and predators) below this depth rely upon a subsidy from energy synthesized by macrophytes and phytoplankton in the photic zone. We used fatty acids (FA) and multiple stable isotopes (MSI) as trophic biomarkers to compare tissues from a suite of primary and secondary consumers across depths (15 and 100 m) at three sites in the San Juan Archipelago. Due to significant site and depth interactions, differences among depths were analyzed for each consumer at each site. FA differed across depths for 8 of 9 herbivores and 4 of 6 predators (PERMANOVA P<0.05). Specific FA were repeatedly identified as driving the differences across all sites and between depths (SIMPER) for each taxon. MSI showed a general enrichment from shallow to deep in d13C for all consumers, but not d34S. The d15N signature in herbivores and suspension feeders consistently increased with depth, whereas predators did not differ across depths. While the exact mechanisms of these differences are still unknown, these results suggest increased omnivory by herbivores with depth through ingestion of particulates and detritus colonized by bacteria.
Gibble, C.M., Kudela, R.M.
WIDESPREAD DETECTION OF THE FRESHWATER TOXIN MICROCYSTIN AT THE LAND-SEA INTERFACE WITHIN MONTEREY BAY, CA
University of California, Santa Cruz
Harmful algae have a worldwide distribution and can form extensive blooms with toxin production in freshwater, estuarine, and marine habitats. Microcystis aeruginosa blooms and associated toxin microcystin (MCY) are a regular occurrence in freshwater systems throughout California, but until recently have not been detected in marine environments. To investigate potential land-sea transfer of this toxin, 28 sites in and around Monterey Bay were surveyed for evidence of MCY toxin in year one (2010-2011). In year two (2011-2012) 4 major watersheds in the Monterey Bay area were surveyed for MCY abundance, nutrients, temperature, and alkalinity to identify potential factors that might be influencing the abundance of MCY at the land-sea interface. MCY was detected in 11 of the 28 sites. Multiple regression analysis indicated that coastal nutrient loading (nitrate, phosphate silicate, ammonium, urea) temperature, and time of year have a statistically significant relationship with the amount of MCY toxin in the environment. Because this toxin has the ability to biomagnify and persist within food webs; increases in blooms of this toxin may increase potential for illness and death of wildlife and humans. The widespread occurrence of this toxin at low to moderate levels demonstrates the potential difficulty of mitigating these impacts.
Giddens, J.L.1, 2*, Conklin, E.J.3, Wiggins, C.H.3, Friedlander, A.M.1,2, Stamoulis, K.A.1 Birkeland,C.1
EXPERIMENTAL REMOVAL OF THE INTRODUCED PREDATOR CEPHALOPHOLIS ARGUS IN PUAKO, HAWAII: A COMMUNITY-BASED APPROACH TO CORAL REEF ECOSYSTEM RESTORATION
1 – University of Hawaii at Manoa, 2 US Geological Survey, Hawaii Cooperative Fisheries Research Unit, 3 The Nature Conservancy Hawaii Marine Program
Introduced predators can reduce biodiversity and abundance of native species by direct predation or indirectly through competition for resources. This research focused on the effects of an introduced grouper (roi, Cephalopholis argus) on native reef-fish populations. Our objectives were to 1) engage the local-community in testing the effects of roi on fish-assemblages with a predator removal experiment and 2) assess the feasibility of roi-removal as a management tool. Overall assemblage metrics (numerical abundance and biomass) and potential competitor abundance did not differ by location six-months after roi-removal. Numbers of small-sized (15 cm TL) fishes increased by 18% percent at the treatment site and decreased by 2% at control locations. Excluding young-of-year from the analysis, the narrow size-range of small (515 cm TL) select prey-species did not differ among locations one-year after roi-removal. Bi-annual monitoring will continue for three years to determine the long-term effects of roi-removal. In addition, the spatial distributions of roi were monitored through a mark and re-capture program. Tagged roi were found to travel distances ~50-150 m from the periphery of the removal area toward its center at a rate of ~ 1 every 1-2 months, demonstrating the feasibility of roi-removal as a management tool in Hawaii.
Gilman, S.E. 1, Wong, J. W. H.2, Chen, S. 2, Hendrix, A.2
Oxygen consumption in relation to cirral activity, wave exposure, and low tide stress in the barnacleBalanus glandula
1 – The Claremont Colleges, 2 – Scripps College
Respiration rates reflect both the metabolic needs of an organism and the effect of the surrounding environment on that organism’s metabolism. We measured the oxygen consumption of individuals of the acorn barnacle Balanus glandula to determine how changes in cirral beating behavior, cirral length, and low tide stress affected energy demand. Surprisingly, respiration rates did not differ significantly among pumping, normal, and fast beats, even though these beats involve different levels of muscle activity. We observed an increase in oxygen consumption after exposure to low tide stress, which driven primarily by changes in the frequency of beating behavior rather than in the respiration rate during beating. Finally, barnacles from a location of high water motion exhibited significantly shorter cirri and lower oxygen consumption for a given body size than those from calmer waters.
Gooding, R.A.*, Harley, C.D.G.
P. OCHRACEUS PREY SIZE PREFERENCE AND FEEDING BEHAVIOURS VARY WITH PREDATOR AND PREY SIZE.
University of British Columbia
The seastar Pisaster ochraceus is predicted to experience increased growth with ocean acidification and warming, while the growth of its preferred prey, the mussel Mytilus trossulus, may decline. This potential divergence in size distributions of predator and prey will likely play a key role in determining how climate change affects their interaction. We found that P. ochraceus preferred prey size, feeding rate, and handling time scaled predictably with both seastar and mussel size. Although seastars preferred mussel sizes that provided the greatest ratio of energy gain per unit feeding time, they generally consumed the same amount of mussel tissue regardless of prey size. This suggests that seastars may prefer to consume a threshold amount of calories rather than trying to consume as much as possible. This apparent limit on tissue consumption could be due to rate-limiting factors (e.g. digestion or assimilation rates) or attempts to limit time spent exposed to risks like desiccation and predation. We will discuss how these potential drivers of P. ochraceus feeding choices lead to different predictions of how climate change might alter P. ochraceus behaviour, as well as how future climate-driven changes to seastar and mussel sizes could affect this important predator-prey interaction.
Goulding, T.C.*, Dayrat, B.
EXPLORING SPECIES DIVERSITY OF MANGROVE GASTROPODS IN THE INDO-WEST PACIFIC
University of California, Merced
Mangrove forests are a harsh habitat for many organisms; as an intertidal habitat, they are flooded with sea water at high-tide and also frequently inundated with fresh water from both tropical rains and river systems. Yet many invertebrates have adapted to mangroves, and gastropods in particular are quite diverse, with about ten gastropod taxa being the most species-rich (e.g., Ellobiidae, Onchidiidae, Cerithiidae, Littorinidae, etc.). However, because mangroves of the Indo-West Pacific remain largely unexplored, their diversity for most gastropod taxa is essentially unknown. In this study, we are undertaking extensive fieldwork in Indo-West Pacific mangroves to estimate gastropod species diversity, delimit species ranges, and investigate the evolutionary history of each gastropod group. We are interested in how gastropod taxa have diversified in mangroves: have pelagic larvae allowed many species a wide geographic range or are many species locally restricted? Are cryptic species often sympatric or allopatric? If cryptic species are sympatric, can we identify distinct microhabitats that the species inhabit? Based on our recent fieldwork in Malaysia, Singapore, India, Borneo and Australia, we can begin to discuss how we have distinguished species in the field and the challenges we face with cryptic species.
STRANGER DANGER: CUE-SPECIFIC RISK ASSESSMENT AND BEHAVIORAL PLASTICITY IN INVASIVE OYSTER DRILLS
University of Washington
Observations of inducible defenses in evolutionarily novel predator-prey interactions are increasingly common. The role that such defenses could play in species invasions depends on what information the prey use to assess risk. Risk information could originate as cues from the predator, other prey in the area, or a combination thereof. In a system where the predator and prey do not share a very long evolutionary history, the prey might not be able to recognize the predator per se, but might instead rely on general risk cues released by injured conspecific prey. I have previously observed this pattern in behavioral responses of Atlantic Oyster Drills (Urosalpinx cinerea), invasive along the west coast of the United States, in response to native red rock crabs (Cancer productus). Though it shares a similar invasion history with Atlantic drills in the Pacific Northwest, Japanese Oyster Drills (Ocenebra inornata) prioritize information sources differently. However, both species of invasive drill recognize predation risk from the native crab itself, and possible mechanisms include associative learning, exaptive recognition based on taxonomic similarity, and evolution following introduction.
Gravem, S.A.*, Morgan, S.G.
THE INDIRECT CASCADING EFFECTS OF SEASTAR PREDATORS ON TIDEPOOL ALGAE ARE MEDIATED BY BEHAVIORAL TRAITS OF INDIVIDUAL SNAILS
University of California, Davis, Bodega Marine Lab
It has become increasingly clear that predators can initiate trophic cascades by altering prey behavior, termed non-consumptive indirect effects (NCIE). However, individual prey traits such as size and hunger level can drastically affect prey behavior and have long been recognized as influential on prey foraging and refuge use. By combining these concepts, we investigated the emergent effects of individual behaviors on non-consumptive trophic cascades. We manipulated individual traits of herbivorous snail prey (Chlorostoma funebralis) including hunger level, size, and density of conspecifics in the laboratory and field and found that they altered refuge use and foraging behavior of snails in response to seastar predators (Leptasterias hexactis). Fed snails mediated strong cascades by reducing feeding and escaping to refuge outside of tidepools when seastars were present. In contrast, hungry snails did not mediate cascades because they did not behaviorally respond to seastar presence. Though neither snail size nor density altered NCIE strength in short-term experiments, snails at high densities exhibited safety in numbers behavior when seastars were present, and large snails reacted more strongly than small snails, despite being at low risk of predation. These finding suggest that individual traits of organisms may have far-reaching effects on community interactions.
Gray, V.*, Allen, B.J.
PHYSIOLOGICAL CONSEQUENCES OF VARIATION IN TEMPERATURE AND FOOD AVAILABILITY FOR THE MARINE SNAIL LOTTIA GIGANTEA
California State University, Long Beach
Marine intertidal invertebrates are likely to be especially vulnerable to global warming as their physiology, behavior, and demography are all critically influenced by local environmental temperatures. Nevertheless, the mechanistic links between abiotic conditions and individual performance are not yet well understood. We are using the owl limpet, Lottia gigantea, as a model organism to identify the physiological consequences of thermal stress on key demographic parameters. We transplanted marked limpets into intertidal plots across a wave exposure gradient on a rocky headland in Rancho Palos Verdes, CA. Chronic heat stress was associated with reductions in survival and annual shell growth, however, the performance decrement varied with local food availability, suggesting that individuals with limited access to resources are less able to mitigate potential costs of thermal stress through physiological mechanisms. Expression levels of stress proteins (e.g., hsp70) were related to limpet growth in complex ways, highlighting the potential for interactions among multiple environmental drivers of organismal performance. The ability to link effects of abiotic stress on key demographic parameters to protein-based bioindicators may provide insight into the potential responses of individuals and populations to future environmental conditions.
Groesbeck, A.S.1*, Salomon, A.K.1, Rowell, K.2, Lepofsky, D.S. 1
Ancient shellfish cultivation in British Columbia: An experimental look at First Nations clam gardens
1 Simon Fraser University, 2 University of Washington
Our investigation integrates ecological, archaeological, and traditional knowledge to examine the traditional use and productivity of ancient clam gardens – beaches with intertidal terraces created by Pacific coastal First Nations. We hypothesized that this ancient form of mariculture increases the growth rates and survivorship of clams by extending high quality clam habitat. We tested this through experimental transplants of native little neck clams (Leukoma staminea) at replicate clam gardens and non-walled beaches on Quadra Island, BC, Canada. We also conducted transect surveys to measure bivalve biomass, community composition, available habitat, and sediment types in both habitats. AIC model comparisons confirm that L. staminea exhibit higher growth rates and biomass within clam gardens and that overall bivalve biomass is higher within clam gardens than unaltered beaches. These structures appear to increase optimum shellfish habitat by altering beach slope. Our findings reveal important insights into traditional resource management and sustainable harvest techniques that can enlighten contemporary strategies for ecological conservation and food security.
Gruman, C.A.1*, Salomon, A.K.1, E. Price2, Bergman, C.M. 2
MAGNITUDE AND MECHANISM: CROSS-SYSTEM EFFECTS OF AND INTRODUCED PREDATOR IN HAIDA GWAII?
1 Simon Fraser University, 2 Gwaii Haanas, Parks Canada
Marine Conservation Area Reserve and Haida Heritage Site off British Columbias North coast have been colonized by invasive Norway rats (Rattus norvegicus). On other island archipelagos, Norway rat invasions have been shown to provoke a terrestrial-marine trophic cascade that drastically alters the structure of intertidal communities. Invasive rats prey heavily on seabirds that forage on rocky shores, resulting in the proliferation of invertebrate grazers (snails and limpets) and subsequent declines of macroalgae. This cross-system trophic cascade drastically alters the structure of the intertidal community. We sought to quantify the magnitude of these indirect effects in Gwaii Haanas and also to determine the extent to which other environmental factors may mediate the strength of the cascade. We compared the abundance of algal species, sessile invertebrates and grazers on islands with and without rats along a gradient of wave action. Final results from mixed effects modelling show that the impacts of this invasive predator in Gwaii Haanas do not mirror those seen elsewhere.
Guenther, R.1,2*, Miklasz, K.2,3, Carrington, E. 2, Martone, P.T.1
ITS A STICKY SITUATION: THE EFFECT OF pH ON THE ADHESION OF RED ALGAL SPORES
1-University of British Columbia, 2-University of Washington, Friday Harbor Laboratories, 3-Stanford University
Algal spores are a rarely studied, yet, extremely important stage of the life cycle of an alga. Whether or not a spore can settle and germinate ultimately determines if the alga can grow and reproduce to complete its life cycle. The decrease in pH of the worlds oceans caused by increased dissolution of atmospheric CO2 (ocean acidification) has been documented to have effects on mature seaweeds, especially calcified species, but the broad effects of pH on spore adhesion have not been studied. We hypothesized that decreases in seawater pH will affect spore settlement and adhesion. This study examined the effect of pH on algal spore adhesion strength and time to settlement of a common intertidal red alga, Pterosiphonia bipinnata. We found that a reduction in pH delays the time to attachment of this species. Under ambient pH, spores settled in approximately 15 hours, however, at low pH, it took spores 26 hours to settle. We also documented a trend in the reduction of strength with which spores attach in the lower pH treatment. Our results suggest that acidification may have unanticipated effects on many seaweed communities, not just those species that calcify. Future studies will help resolve these intriguing patterns.
Hameed S.O. 1, Wilson White J. 1,2, Miller, S.H.1, Nickols, K.1, Morgan, S.G.1
Coupled reproduction and settlement, connectivity, and local retention of rocky shore metapopulations in an upwelling region
1 – Bodega Marine Laboratory, University of California, Davis, 2 – University of North Carolina, Wilmington
Identifying marine population connectivity is important for designing effective marine protected area networks that will promote metapopulation persistence, but empirically determining population connectivity is challenging for microscopic larvae that typically develop for weeks in the plankton. Many estimates of larval dispersal have relied solely on coastal oceanography and larval settlement patterns while neglecting reproductive output. We estimated population connectivity of a model species of crab,Petrolisthes cinctipes, using a hierarchical Bayesian modeling approach that has been used in seed dispersal studies. We combined a prior estimate of larval dispersal (dispersal kernel) based on nearshore currents with field data of habitat quality, larval production and post-larval settlement from populations along the California coastline. Counter to conventional wisdom, our model suggests that local retention and coupling of reproductive output and larval settlement may be common for a species that develops for a month on the inner shelf in a region of strong, persistent upwelling. This approach improves quantitative estimates of population connectivity that may be used for the adaptive management of Californias marine protected area networks.
Effects of Multiple stressors on the growth of an intertidal rockweed
University of Washington
The rockweed Fucus distichus experiences gradients of tidal immersion, competition, and herbivory across its vertical range in the rocky intertidal. I designed two experiments to separate the effects of these stressors and examine potential non-additivity. In a test of F. distichus growth under simulated intertidal and subtidal conditions growth was slower when always immersed, herbivorous snails had a stronger effect than immersion in reducing growth, and the combined effects were additive. Herbivory had a greater effect in reducing epiphyte load than immersion. In a test of growth across immersion time in the absence of herbivory, F. distichus had the lowest growth when always immersed and manual removal of epiphytes increased growth additively.
Haupt, A.J.1, Woodson, B. 2, Micheli F. 2, Palumbi, S.R.2
SUBTLE GENETIC STRUCTURE IN THE COMMERCIALLY FISHED WARTY SEA CUCUMBER
1 – NOAA Northwest Fisheries Science Center, 2 Hopkins Marine Station, Stanford University
Understanding dispersal of marine organisms is critical to managing commercially important species at appropriate scales. The warty sea cucumber, Parastichopus parvimensis, is fished commercially in both California, USA, and Baja California, Mexico, but little is known about the status of fisheries or if biologically separate stocks exist. P. parvimensis has a long pelagic larval duration of 50-90 days, which may translate to high connectivity throughout the species range (Monterey, CA, USA to Baha Asuncion, BCS, Mexico). Oceanographic processes associated with major capes, Point Conception in California and Punta Eugenia in Mexico, may create dispersal barriers and have been previously identified as areas of interest for concordant phylogeographic breaks. Analysis of mtDNA COI locus and five microsatellite loci revealed subtle genetic structure associated with Punta Eugenia, but no genetic structure associated with Point Conception in California. Oceanographic changes including upwelling, eddies, and fronts may act as a barrier to dispersal separating populations of P. parvimensis south of Punta Eugenia from those populations to the north. These data have important implications for management of this fishery and indicate that populations south of Punta Eugenia likely do not receive biologically meaningful input of larvae from northern populations to supplement the local fishery.
Hayford, H.A.*, ODonnell, M.J., Carrington, E.
Low speed, high tech: Radio tracking intertidal snails
Friday Harbor Labs, University of Washington
Ecologists gain insight into organismal behavior from controlled experiments, but it is critical to determine if experimental patterns hold true for organisms in their natural habitats. Free-ranging individuals are often marked to track position in space and time. Radio frequency identification (RFID) is a common method of marking individuals in cases where visual tracking is unreliable. While RFID has long been used in fisheries studies, recent technological advances in passive integrated transponder (PIT) tags have decreased their size, enabling use on small marine invertebrates. We used RFID to explore vertical migration of the intertidal snail Nucella ostrina. In previous caged experiments, we found a periodic foraging pattern that followed the 14-day lunar tidal cycle; this pattern correlated with reduced thermal risk and increased abundance in high shore field surveys. We tracked free-ranging snails, using a hand-held tag reader, to determine whether snails were moving laterally into high shore survey areas (feeding continuously) or migrating vertically from low shore refuges (feeding periodically). We found that N. ostrina moved up shore when predicted: during periods of high foraging. RFID allowed us to track small animals over a relatively large stretch of shoreline and to correlate population density changes to movement of individuals.
EVALUATING REEF FISH POPULATION STATUS IN THE MAIN HAWAIIAN ISLANDS
School of Fisheries University of Washington
Many studies of remote, uninhabited coral reefs have focused on describing the great abundance of fish compared to populated reefs. Fishing has often been indicated as an important factor contributing to drastic differences in fish abundance and some consider this evidence of overfishing. However, other factors such as habitat complexity also impact fish abundance. Furthermore, we expect there to be less fish where humans are present, which means that simple abundance comparisons may be inappropriate for assessing whether a coral reef fishery is overfished. Using a large data set that spans the Hawaiian archipelago, I evaluated the difference in fish abundance between the unpopulated Northwestern Hawaiian Islands (NWHI) and the populated Main Hawaiian Islands (MHI) while controlling for habitat differences. I then evaluated the status of fish in the MHI using a decision rule based on a multi-species extension of the sustainable yield concept whereby a hypothesized window of sustainable yield was set at 0.25-0.50 of unfished biomass estimated from the NWHI. Preliminary results indicate that within similar habitat types, fish family abundance patterns are variable and that fisheries targets, while always less abundant in the MHI, are not all at levels below which we may expect to be sustainable.
Heras, J.1*, Aguilar, A.1, Rockfish Sequencing Consortium2,3,4
A COMPARATIVE GENOMIC STUDY OF MARINE ROCKFISHES (GENUS SEBASTES) TO UNDERSTAND PATTERNS OF MARINE SPECIATION AND ADAPTATION
1 – University of California, Merced, 2 – University of Southern California, 3 – Juniata College, 4 Southwest Fisheries Science Center, National Marine Fisheries
The genetic mechanisms of marine speciation and adaptation are not completely understood. Marine systems provide a unique medium for speciation because of the potential for gene flow to occur between extensive distances, which differ from traditional views of speciation within most terrestrial systems. Rockfishes (genus Sebastes) are a prime system for studying adaptive radiations within marine systems. Using rockfishes as a model for understanding the genetic facets of adaptation and speciation, we selected genomes that were sequenced by the rockfish consortium from two rockfish species (Sebastes nigrocinctus and S. rubrivinctus) to identify signatures of natural selection. These closely related species have divergent life spans (estimated 116 and 38 years for S. nigrocinctus and S. rubrivinctus, respectively), which can be utilized to elucidate genetic patterns of longevity. We identified orthologous sequence pairs between the two species and estimated nonsynonymous (Ka) and synonymous (Ks) substitutions. We identified 14,186 orthologous gene pairs between the two species and annotated genes that were putative candidates that were subject to positive Darwinian selection. This study has provided a foundation for determining the mechanisms of speciation within marine systems.
Hillard, H.*, Carpenter, R.C.
EFFECTS OF SARGASSUM PACIFICUM ON THE CALICIFCATION OF JUVENILE PORITES RUS IN ELEVATED CO2 CONDITIONS
California State University, Northridge
Ocean acidification, the decrease in the pH and carbonate ion concentration due to the uptake of anthropogenic CO2, poses a threat to coral reefs worldwide as studies predict the decline of calcifying organisms and increasing growth of fleshy, non-calcified algae. Future recovery of coral reefs will depend on the ability of juvenile corals to survive in association with macroalgae. Preliminary data using an integrated water sampler combined with a potentiometric titrator and spectophotometric techniques revealed a slightly higher pH inside the canopy of Sargassum pacificum (20-30 holdfasts/.25 m2) than outside the canopy. I tested the hypothesis that S. pacificum, by changing the carbonate chemistry, creates a more favorable microhabitat for juvenile Porites rus calcification by conducting a three week field experiment with three caged treatments (S. pacificum + P. rus, P. rus, P. rus + algal mimic). To further isolate the effect of macroalgae on coral calcification in elevated CO2 conditions, I exposed juvenile P. rus to a factorial combination of two pCO2 levels (380, 800 atm) with and without S. pacificum. This research will provide a unique opportunity to explore the role of fleshy macroalgae as a refuge for juvenile corals to survive and calcify under future CO2 conditions.
Holtz, S.B.*, Dickson, K.A.
EXTRAOCULAR MUSCLES AS A POTENTIAL HEAT SOURCE FOR CRANIAL ENDOTHERMY IN TUNAS
California State University Fullerton
In tunas (family Scombridae), counter-current heat exchangers, retia mirabilia, conserve metabolic heat, allowing eye and brain temperatures to be elevated above ambient water temperature (cranial endothermy). Although the retia have been described, little is known about the source of metabolic heat used in cranial endothermy. We hypothesized that one or more of the six extraocular muscles (EOMs) serve as the heat source for cranial endothermy. The activity of the enzyme citrate synthase (CS units g-1muscle) and muscle mass were measured as indices of heat production potential in all six EOMs of 3 tunas and two ectothermic scombrids. EOMs were also examined histologically for any structural modifications for heat production. The EOM with the greatest CS activity and relative mass varied interspecifically. In most comparisons, the EOMs of ectothermic sister species had a CS activity and relative mass greater than or equal to that of the endothermic tunas. No structural modifications for heat production were observed. Overall, this study did not provide evidence that Yellowfin, Bluefin, or Skipjack tunas have evolved an elevated heat production capacity in their EOMs for cranial endothermy. Therefore, the presence of retia mirabilia alone may be sufficient to maintain elevated cranial temperatures in these species.
Honey, K.T.1*, He, X.2
INTEGRATING NOVEL DATA-LIMITED FISHERY METHODS WITH MARINE RESERVES: RESERVE-BASED SPAWNING POTENTIAL RATIO (SPR)
1 – Stanford University, 2 – NOAA Fisheries, Southwest Fisheries Science Center
Using limited ecology and fishery information to inform management decisions remains a challenge for improved fisheries management. One specific challenge today is: How can we integrate local-scale data on fish populations, such as SCUBA and submersible surveys collected on the scale of a single marine reserve, into fisheries models to provide reference points to inform fisheries management? To address this, we develop a new analytical tool for use in information-limited situations by extending a class of biological reference points, known as non-equilibrium measures of spawning potential ratio (SPR). We integrate these methods with data from no-take marine reserves and call our method reserve-based SPR. The methods use simulation models, loosely based on life history of West Coast rockfish, which incorporate uncertainties in natural mortality, stock dynamics, optimal harvest rates, and stock status for nearshore species. Our method performs well at estimating sustainable yield without requiring an assumption of equilibrium, as some data-limited tools require. Results are robust to assumptions about natural mortality, fishing mortality, and sample sizes for age demographics. It is sensitive to assumptions about recruitment variability. Overall, reserve-based SPR is a practical, easy-to-implement, information-limited method that can bring together conservation-based tools, specifically marine reserves, with fisheries management approaches.
WHY NATIVE FISHES DWELL IN INVASIVE KELP: POTENTIAL MECHANISMS DRIVING HABITAT ASSOCIATIONS WITH UNDARIA IN MONTEREY HARBOR
Moss Landing Marine Laboratories
Kelps are important sources of biogenic habitat along shallow rocky coasts of cold-water regions worldwide. The invasion of Monterey Harbor by the kelp Undaria pinnatifida provides a unique opportunity to study how organisms interact with a new kelp habitat. In prior work I compared fish assemblages associated with Undaria to fish assemblages in a broad spectrum of other benthic habitats in Monterey Harbor, and demonstrated that although fish density and composition varied throughout the year, in all months in which fishes were present they used Undaria habitat disproportionately more than other available habitat. Here, I examined food availability and habitat structure as potential drivers of this pattern. Diet analysis of Kelpfishes indicated that gut contents did not significantly differ among habitats with or without Undaria, suggesting that comparable prey items are available to fishes inhabiting both habitat types and that food may not drive habitat selection. A field experiment showed thatUndaria-associated fishes frequently use habitat with complex structure, and that they readily associate with artificial Undaria, suggesting that the complex structure of Undaria is the key characteristic driving habitat selection by fishes. I suggest that the non-native kelp Undaria benefits fishes through the creation of habitat structure.
EELGRASS HABITAT LOSS AND BIODIVERSITY: STRUCTURAL COMPLEXITY MODIFIES EFFECTS OF DISTURBANCE ON EPIFAUNA
San Diego State University, Coastal & Marine Institute
Habitat loss influences community structure in terrestrial and marine systems. However, theoretical and empirical evidence suggests that community structure may not change with habitat loss until a threshold of loss is reached, causing a non-linear relationship between loss and biodiversity. In seagrass habitat, disturbances at multiple scales fragment patches causing a continuum of habitat loss and fragmentation, but structural complexity (e.g. shoot density) also varies among patches. I used artificial eelgrass (Zostera marina) patches to test whether structural complexity modifies effects of habitat loss on epifaunal community structure. I specifically tested the hypothesis that low structural complexity would decrease the threshold amount of loss necessary to reduce biodiversity. We allowed artificial eelgrass patches of each of three shoot densities to be colonized by epifauna in San Diego Bay, CA. We then removed different amounts of habitat from each patch to create a continuum of habitat loss (0 90% ) for each shoot density treatment. The hypothesis was supported: species richness and epifaunal density decreased after a threshold of loss (70%) was reached, but only in the low shoot density treatment. However, multivariate analyses revealed that the major driver of community composition was structural complexity, rather than habitat loss.
Hughes, B.B.1*, Eby, R.2, Van Dyke, E.2
Sea otters mediate negative eutrophication effects on seagrass through a multi-level trophic cascade
1 University of California Santa Cruz, 2 Elkhorn Slough National Estuarine Research Reserve
Ecosystems today are under threats from multiple natural and anthropogenic disturbances that alter resource driven (bottom-up) and consumer driven (top-down) pathways causing an increase in the rate of change that leads to alternate stable states. We explored the hypothesis that top-down forcing (keystone predation) can mitigate the negative effects of anthropogenic change to bottom-up forcing (eutrophication) in a seagrass system. To test this hypothesis we combined results from long-term monitoring, comparative field surveys, and mesocosm and field experiments. Our results demonstrate that sea otters (Enhydra lutris) are able to maintain the functioning and persistence of eelgrass (Zostera marina) through a multi-level trophic cascade. In our primary study system, Elkhorn Slough, CA, eelgrass populations have demonstrated a high degree of resiliency despite intense nutrient loading and eutrophication that have persisted for over 40 years. This period of resiliency coincided with the migration of sea otters into the estuary in the 1984, since then both populations have expanded in tandem through time. Given the known effects of eutrophication, habitat alterations, hunting, and climate change, it is essential that ecologists and managers consider both bottom-up and top-down influences when assessing the state of an ecosystem.
Iacchei, M.1*,Ben-Horin, T.2, Selkoe, K.A.1,3, Bird, C.E.4, Garca-Rodrguez, F.J.5, Toonen, R.J.1
self-recruitment in the California spiny lobster (Panulirus interruptus) despite AN EXtremely long pelagic duration
1 – Hawaii Institute of Marine Biology, 2 – University of California Santa Barbara, 3 – National Center for Ecological Analysis and Synthesis, 4 – Texas A&M Corpus Christi, 5 – Centro de Investigaciones Biolgicas del Noroeste
Populations of marine species with long-lived pelagic larvae (>4 months) are generally thought to have great dispersal potential and show minimal population structure across broad geographic ranges. Here, we investigate the dispersal patterns of the California spiny lobster (Panulirus interruptus), which spends the first 240 to 330 days of life in the plankton. We use seven nuclear microsatellite markers and mitochondrial COI sequence data from 1102 individuals collected across 17 different sites throughout the species range from Pt. Conception, California to Bahia Magdalena, Mexico. At the regional scale, there seems to be high gene flow, with the two most common mtDNA haplotypes shared across all sites. Amidst this backdrop of connectivity; however, there is significant overall population differentiation in both mtDNA (ST = 0.006, p = 0.001) and microsatellites (FST = 0.004, p < 0.001). Analyses of co-ancestry relationships demonstrate significantly greater kinship between lobsters within sites than among sites, and sites with the highest FST values also have the highest levels of kinship. The California spiny lobster, with almost limitless dispersal potential, appears to have adapted to increase self-recruitment. We discuss the implications of these results for MPA design and lobster fisheries management in the USA and Mexico.
Ingeman, K.I.*, Hixon, M.A.
NOT JUST ANOTHER MOUTH TO FEED: INVASIVE LIONFISH ALTER NATIVE PREY POPULATION DYNAMICS
Oregon State University
Species introductions have been identified as one of the greatest threats to global biodiversity and can drastically alter population, community and ecosystem-level properties of invaded systems. As predators play a central role in prey population dynamics, it is essential to determine whether invasive predators alter predation-mediated regulatory mechanisms, potentially destabilizing prey populations. The invasive Indo-Pacific lionfish (Pterois volitans) is a new mesopredator that voraciously consumes native coral-reef fishes of the tropical Western Atlantic and Caribbean. The fairy basslet (Gramma loreto) is a common prey of lionfish, and pre-invasion research has demonstrated that basslet populations undergo regulating density-dependent mortality due to predation. We previously compared mortality rates in fairy basslet before vs. after the lionfish invasion and demonstrated that basslet mortality remains density-dependant, but has undergone a density-independent increase since the arrival of lionfish. Because such before-after comparisons confound the effects of the invasion with uncontrolled factors, we followed up this work with a controlled field experiment, manipulating both basslet density and lionfish presence/absence in a cross-factored design. Preliminary results indicate that lionfish predation can drastically increase mortality even at low prey density and that the density-mortality patterns can vary depending on temporal scale of the experiment.
Janot, K.G.*, Martone, P.T.
MORPHOMETRICS AND MATERIAL PROPERTIES OF JOINTS IN THREE SPECIES OF ARTICULATED CORALLINE ALGAE
University of British Columbia, Vancouver, BC, Canada
For upright macroalgae living in the wave-swept intertidal, the ability to bend over and reduce drag when hit by waves is considered necessary for survival. While fleshy seaweeds are flexible throughout their thalli, articulated corallines bend only at discrete uncalcified joints along otherwise calcified fronds. These joints, called genicula, must simultaneously resist breakage due to stress amplification while remaining sufficiently flexible to allow whole fronds to bend in flow. Previous computational modeling of the articulated coralline Calliarthron cheilosporioides demonstrated that genicular characteristics may be optimally designed for minimizing joint stress while maximizing whole frond flexibility. Moreover, Varying morphological and material parameters revealed trade-offs; for example, decreasing genicular cross-sectional area increases flexibility (reducing drag), but also increases stress (increasing risk of breakage). But do these patterns hold in other morphologicaly-distinct articulated corallines? For example, Based on this model, we predicted that articulated coralline species in highly wave-exposed habitats should exhibit longer genicula, and fewer intergenicula, than those found in less hydrodynamically stressful environments. To test this prediction and explore other morphometric patterns, morphological dimensions and material properties of three articulated coralline species from different hydrodynamic environments were compared. Comparisons lend insight into the selective pressures that may have led to the repeated evolution of articulated morphologies.
Janousek, C.N.*, Mayo, C.
PLANT GROWTH UNDER SALINITY AND INUNDATION STRESS: IMPLICATIONS FOR SEA-LEVEL RISE EFFECTS ON TIDAL WETLAND FUNCTION
Western Ecology Division, US Environmental Protection Agency
Climate change and sea-level rise (SLR) may increase salinity or inundation duration for tidal wetland organisms. To test the effects of these stressors on wetland productivity, we transplanted seedlings of seven common plant species to polyhaline, mesohaline and oligohaline tidal marshes on the Oregon coast. At each site, juvenile plants were grown at local mean higher high water (a typical mid-marsh elevation) and at 25 and 50 cm below MHHW to increase inundation. Plants were harvested after a short growing season to determine above- and below-ground biomass. Shoot and root production declined for all species with increasing inundation. Growth also varied by site, with the lowest rates in the most saline wetland. We combined water-level and salinity measurements at our sites to estimate a salinity exposure index for each treatment. Higher values of the index were correlated with lower productivity for all species and with declines in root versus shoot production. Species tolerances to inundation and salinity stress varied, but even species common to lower, more saline marshes declined in productivity. Our results suggest that relative SLR in Pacific Northwest tidal marshes may reduce above-ground production for consumers and possibly reduce wetland accretion potential because of reduced root growth.
Jarvis, M.A.*, Shanks, A.L.
FRONTS CONCENTRATE LARVAE IN THE VERY NEARSHORE
Oregon Institute of Marine Biology
Prior research in our lab suggests that many of the foam lines visible in the nearshore may be surface manifestations of fronts. A front is a boundary between two different water masses, and is often accompanied by a surface convergence that may favor concentration of particles such as detritus and foam. During north winds, a topographical front is commonly present at the mouth of Sunset Bay, near Charleston, Oregon. I hypothesized that the foam line at Sunset Bay is a surface convergence that concentrates larvae and other zooplankton. To test this, I released drifters and took plankton tows across the foam line of the front at Sunset Bay during the summers of 2011 and 2012. Drifter data suggest that the foam line is indeed a surface convergence, and preliminary zooplankton samples provide evidence for the concentration of many taxa of larvae, including crabs, barnacles, and bivalves, in the front-associated surface foam line. Nevertheless, the concentration of larvae in the foam line was not always consistent, suggesting the interaction of other variables in nearshore larval distribution, including wind intensity and direction as well as stability of the front and strength of the resulting surface convergence.
Jenkinson, R.S. 1,2*, Hovel, K.A.1
GEOGRPAHIC PATTERNS OF PREDATION ON SUBTIDAL REEFS OF THE SOUTHERN CALIFORNIA BIGHT
1- San Diego State University, 2- University of California Davis
The trophic role of predators often varies within similar habitat over geographic space. Mechanisms leading to latitudinal variation in species interaction strength and type can include site-specific levels of predator abundance, the sizes of predator and prey species, and variation in oceanographic conditions. Within subtidal reefs of the Southern California Bight (SCB), predators such as sunflower stars, spiny lobster, and sheephead may control sea urchin populations, but studies testing for strong top-down control of urchins are lacking at broad spatial scales. We conducted surveys and tethering experiments at 19 sites spanning over 1700 km to assess the generality, mechanisms, and strength of potential trophic cascades induced by these predators. Across all study sites there was a significant negative correlation between the abundance of predators and urchins. However, this relationship appears to be site specific with many sites harboring high densities both of predators and urchins. Predator size, which is correlated to harvest pressure at a given site, is also negatively correlated with urchin abundance. Tethering experiments suggest that predation rates depend primarily on urchin behavior, rather than predator abundance. These results elucidate the complexities of species interactions and caution against oversimplifying the role predators play in these subtidal communities.
Jensen, C.M.1,2* , Rothwell, R.V.1,2 , Johnson, E.R.1,3 , Condamoor, M.1,3 , Patil, M.N.1,4 , Largier, J.5 , Schmidt, C.1,6
A GEOSPATIAL ANALYSIS OF HARMFUL ALGAL BLOOMS ALONG THE CALIFORNIA COAST
1 NASA Ames DEVELOP Program, NASA Ames Research Center, 2 California State University, San Francisco, 3 University of California, Los Angeles, 4 Monta Vista High School, 5 University of California, Davis Bodega Marina Laboratory, 6 Bay Area Environmental Research Institute
Algal blooms are natural phenomena consisting of the rapid growth of phytoplankton populations. Some blooms have negative ecological and public health effects due to toxin production and removal of oxygen from the water column.In recent years, such harmful algal blooms (HABs) have been linked to human illness, economic loss from decreased fishing, and marine life mortality due to eutrophication.A HAB event occurred along the California coast in August 2011, resulting in economic impacts of approximately $82 million. This study tracked the space-time pattern of numerous blooms during August-October 2011 using NASA Earth observing systems (EOS) to understand the structure of these recurrent bloom events. Aqua MODIS images were used to quantify surface chlorophyll- levels, and to map the extent and development of all autumn algal blooms. The relation between sea surface temperature, ocean surface topography, and algal blooms was further explored with AVHRR and Jason-2 satellite data. A Generalized Additive Model (GAM) was used to identify the environmental factors most statistically influential in algal blooms and specifically in HAB events. Results from this study will assist Californias Departments of Public Health and Fish & Game in mitigating and managing the impact of future HABs.
Jensen, M.M.*, Denny, M.W.
WHAT FACTORS AFFECT THE MAGNITUDE OF WAVE IMPACT FORCES?
Hopkins Marine Station, Stanford University
Hydrodynamic forces produced by breaking waves play a major role in shaping intertidal communities. While classical hydrodynamic forces are well-characterized, transient forces at wave impact remain largely unstudied. These force spikes — called impingement forces — are assumed to be the largest hydrodynamic forces acting on intertidal plants and animals. Despite the probable importance of impingement, factors likely to affect it — as well as the mechanism driving it — have remained a mystery. In particular, it is important to know whether impingement scales with volume or area of an organism: the former can limit size, the latter cannot. To determine how object area, volume, and drag coefficient affect impingement magnitude, rectangular prisms, cylinders, and spheres were exposed to simulated waves from a gravity-driven water cannon. Data show that impingement scales with both the area and drag coefficient of the shapes tested. Analysis of the water cannon jet shows a spike in jet velocity concomitant with measured impingement forces. These results strongly suggest that transient wave impacts are caused by brief increases in drag associated with turbulence at the wave front, rather than a separate impact force. Consequently, impingement is not likely to limit organism size.
Johansson, M.L.1*, Raimondi, P.T.2, Reed, D.C.3, Coelho, N.C.4, Serro, E.A.4, Alberto, F.A.1
LOOKING INTO THE BLACK BOX: SIMULATING THE ROLE OF SELF-FERTILIZATION AND MORTALITY IN THE GENETIC STRUCTURE OF GIANT KELP
1 University of Wisconsin, Milwaukee, 2 University of California, Santa Cruz, 3 University of California, Santa Barbara, 4 University of Algarve
The availability of hyper-variable molecular markers has led to a proliferation of studies on spatial genetic structure (SGS) of populations. SGS and ecological studies can be compared to gain additional insights, and computer simulations used to illuminate the underlying causes of mismatches. Here we report a SGS and simulation-based study on self-fertilization in Macrocystis pyrifera. We demonstrate that SGS is weaker than expected, and use simulations to identify a mating system and early mortality rates where individual heterozygosity distributions fit the observed data. Two of three populations showed no significant relationship between kinship and geographic distance. While we simulated complete inbreeding (selfing), full siblings, half siblings, and first cousins at levels ranging from 0 to 100% with and without mortality, only selfing with mortality achieved 2 values that were not significantly different from zero. Best fits were seen between 31 and 42% selfing. Inbreeding depression (increased mortality for inbred vs. outcrossed individuals) ranged from 0.6996 to 0.7244. The results suggest that density-dependent mortality in early life structures Macrocystis populations, with few highly inbred individuals surviving. This work deals exclusively with selfing, and not with lesser inbreeding. In small, isolated populations, among-population inbreeding may still pose a significant risk to persistence.
Johnson, D.W.*, Semmens, B.X.
THE RECRUITMENT PROBLEM REVISITED: ANALYZING PHENOTYPE- AND DENSITY-DEPENDENT RECRUITMENT
Scripps Institution of Oceanography
Relationships between adult spawning stock and the abundance of recruits can be notoriously variable. Indeed, for decades, fisheries scientists referred to the difficulty of predicting the number of surviving juveniles as the recruitment problem. One source of dissatisfaction is that although many stock-recruit relationships show signs of density dependence, simple, density-dependent models often provide little explanatory power, suggesting that other factors may play a large role in driving recruitment variability.
A growing body of research has focused on the roles of phenotypic variation and selective mortality as sources of variability in recruitment. Emerging patterns indicate that mortality is often extremely selective, but it is unclear how selective mortality within cohorts translates to survival differences among cohorts, especially when survival is density dependent. Here, we show how phenotypic selection analyses can be integrated with analyses of density-dependent survival to improve our understanding of recruitment variability. We then apply these techniques to studies of recruitment in salmonids and reef fishes. Analyses that combine phenotype- and density-dependent survival can vastly improve explanatory power of stock-recruitment relationships. Moreover, these analyses reveal that phenotypic characteristics of fish (e.g., variation in average size) can substantially affect recruitment, even in the presence of strong density dependence.
Johnson, M.D.*, Price, N.N., Smith, J.E.
EFFECTS OF ELEVATED CO2 ON GROWTH AND PHYSIOLOGY OF SOME TROPICAL AND TEMPERATE MACROALGAE: IMPLICATIONS FOR OCEAN ACIDIFICATION
Scripps Institution of Oceanography
Despite the heightened awareness to ocean acidification (OA) effects on marine organisms, few studies have explored the implications for fleshy and calcified algae. CO2 enrichment experiments were conducted to elucidate the physiological effects of OA on fleshy and calcified algae from tropical and temperate ecosystems. Algal growth/calcification, pigment content, and activity of carbonic anhydrase, an enzyme used as a carbon concentrating mechanism (CCM) were measured in algae exposed to control and CO2 treatments for two weeks. Although the magnitude of response to CO2 enrichment varied by species, there was a consistent negative impact of OA on calcified algae and a positive impact on some fleshy algae, irrespective of ecosystem. The response of pigment content and CA activity to OA varied by species, with lower pigment concentrations after exposure to CO2 treatments for tropical fleshy and calcified species. For temperate species, pigment concentration was higher in fleshy algae exposed to CO2enrichment but was lower in the calcified species. CO2 enrichment effects on CA activity was highly species dependent, with upregulation of CA activity at high CO2 in two fleshy species and one calcified species. This study provides insight into potential physiological mechanisms that underlie organismal response to future ocean acidification.
Jones, C.L.1, Deza, A.A.1*, Hoesterey, J.C.1, Patonai, K.1, Hubbard, D.2, Lehman, P.3, Page, H.M.1, Schroeter. S.C.1
ASSESSING BIRD ABUNDANCE AND ASSEMBLAGE STRUCTURE IN TIDAL WETLANDS: IMPLICATIONS FOR RESTORATION SUCCESS
1 Marine Science Institute, University of California, Santa Barbara, 2 Coastal Restoration Consultants, Inc., 3 11192 Portobelo Drive, San Diego, CA 92124
Bird communities are a critical component of tidal wetlands and constitute an important measure of the success of coastal wetland restoration. We present a statistical design to examine how bird assemblages might vary among both natural and restored tidal wetlands. Our study focused on a newly constructed wetland, San Dieguito Lagoon (SDL), and compared it to three natural reference wetlands spanning the Southern California Bight. Bird count data was taken from all four wetlands during winter and spring of 2011 and 2012 using sample survey data. Shortly after its construction, total bird density and species richness at SDL was within the range observed at the reference wetlands. In contrast to these univariate measures, multivariate analyses indicated much greater differences in assemblage structure between SDL and the reference wetlands than among the reference wetlands. Further multivariate analyses were done by partitioning assemblages into guilds (e.g. waterfowl, shorebirds) revealed that the abundance of waterfowl in SDL contributed to the differences in bird assemblages between the restored and natural wetlands. SDL has a considerable amount of open water habitat compared to the reference wetlands, which is likely driving the differences we observed.
Jorgensen, S.J.1,2, Estess, E.E.1,2*, Arnoldi, N.S.2, Chapple, T.K.2, Rckert, M.3, Anderson, S.D.4, Block, B.B.2
EATING OR MEETING? DIVE PATTERNS IN THE WHITE SHARK CAF
1 – Monterey Bay Aquarium, 2- Hopkins Marine Station, Stanford University, 3 – Universit Paris VI, 4 –Point Reyes National Seashore
Determining how mobile ocean predators utilize the pelagic environment is vital to understanding the dynamics of oceanic species and ecosystems. Northeastern Pacific white sharks (Carcharodon carcharias) gather seasonally in an oligotrophic region of the Pacific known as the white shark caf, but the purpose of this annual congregation remains unclear. We developed a clustering analysis to distinguish between white shark diving patterns recorded from electronic tags. We found four dominant and distinctive behavioral clusters matching previously described behavioral patterns, including two distinctive offshore diving modes. Once validated, we mapped the occurrence of these behavior modes in space and time. Our results demonstrated spatial, temporal, and sex-based structure, previously unrecognized, and provide new insights for testing competing hypotheses for the purpose of the caf.
Jurgens, L.J.*, Gaylord, B.
Mass mortality of purple urchins over a 100 km swath of north-central California coastline
Bodega Marine Laboratory, University of California Davis
Large-scale mass mortalities have the potential to drive dramatic and persistent ecosystem changes, and may be increasing in frequency. However, due to challenges in detecting and responding to these unpredictable events, many are inadequately documented. In late August 2011, a harmful algal bloom (HAB) along the north-central California coast coincided with widespread invertebrate mortality across multiple taxa. Here we report on the severity and spatial pattern of shoreline mortality related to this bloom. In particular, previously abundant intertidal populations of purple sea urchins, Strongylocentrotus purpuratus, suffered over 99.9% mortality across a 100 km stretch of coast within a prime portion of the species range.
Kanive, P.E.1*, Jorgensen, S.J.2, Chapple, T.K.3, Anderson, S.4, Block, B.A.3, Rotella, J.J.1
USING MARK-RECAPTURE METHODS TO ESTIMATE APPARENT SURVIVAL OF WHITE SHARKS (Carcharodon carcharias) OFF CENTRAL CALIFORNIA
1 Montana State University, 2 Monterey Bay Aquarium, 3 Hopkins Marine Station of Stanford University, 4 Inverness, Ca
Though understanding species vital rates is imperative for developing reasonable conservation strategies, unbiased determination of these rates can be challenging, especially with marine species. Initial estimates of white shark (Carcharodon carcharias) abundance in the northearstern Pacific have indicated relatively low numbers of sub-adult and adults, however, nothing is known about their vital rates. Our goal was to estimate annual apparent survival for white sharks off central California and to test for differences in sex-specific survival using mark-recapture methods. We used photography and video to identify or mark individual sharks based on unique dorsal fin morphology . From these data we determined apparent survival and detection probability using the software program LOLASURVIV. We found a lower detection probability for females and a sex ratio skewed towards males. Annual apparent survival did not differ between sexes and was time invariant. This is an important step towards understanding the status of the population of white sharks off Central California.
Kashef, N.S1,2*, Sogard, S.M.2, Fisher, R. 2, Largier, J.L.3
ONTOGENY OF CRITICAL SWIMMING SPEED OF LARVAL AND PELAGIC JUVENILE ROCKFISHES (SEBASTES SPP.)
1 – Moss Landing Marine Laboratories 2 – NOAA Fisheries, SWFSC Fisheries Ecology Division, 3- Bodega Marine Laboratory, University of California Davis
Understanding the mechanisms that affect larval dispersal is critical to the management of marine populations. Rockfishes (Sebastes spp.) do not settle to demersal habitats immediately after metamorphosis, but instead remain in the water column for an additional period of weeks to months. It is traditionally thought that young rockfishes are planktonic, moving at the mercy of ocean currents, but this assumption is unverified. In this study critical swimming capabilities of larval and pelagic juvenile stages of six rockfish species are evaluated to determine their ability to behaviorally influence dispersal. Rockfish larvae have critical swimming speeds of 0.5 1.8 cm s-1 (1-3 body lengths per second (bl s-1)) at parturition, whereas newly settled juveniles are capable of swimming 8.6 53.5 cms-1 (5-9 bl s-1). Sebastesspp. critical swimming speeds are substantially lower than those obtained from larvae and juveniles of tropical species at similar body sizes. Rockfishes, however, have comparable swimming speeds to some tropical species at settlement, since rockfishes settle at larger sizes. The increasing ability of rockfishes to out swim current velocities throughout their pelagic life history phase, acting as nekton rather than plankton, enhances both retention and dispersal potential and has important implications for survival and distribution.
Keeling, B.E. *S, Salomon, A.K., Hessing-Lewis, M.L.
QUANTIFYING THE MAGNITUDE OF PACIFIC HERRING (CLUPEA PALLASI) EGG LOSS FOLLOWING ANNUAL SPAWN EVENTS
Simon Fraser University
Pacific herring (Clupea pallasi) are an integral component of marine ecosystems from Southeast Alaska to Northern California, providing a key source of food for marine predators, and supporting commercial and subsistence fisheries for coastal communities. Despite annual fishing closures, herring catch in British Columbia has declined over the past 50 years. In order to improve future stock management, we quantified herring egg loss rates post spawn events, a key source of uncertainty in current stock assessment models. We conducted visual dive surveys at herring spawn locations on the Central Coast of BC to estimate herring egg loss rates and the biological and physical factors driving egg loss. We monitored egg abundance at 9 sites throughout the incubation period, and found an average egg loss rate of 4.25% per day. Cumulative estimated egg loss over the incubation period was an average of 79.43%. Using model selection, we are also determining the relative impacts of various factors such as depth, predator abundance, and wave exposure on egg loss. Adjusting spawn survey estimates with a daily egg loss rate further strengthens the current herring stock assessment model, and our analysis demonstrates key ecological factors governing herring populations.
Kim, J.-H.1*, Kim, K.Y. 1, Kang, E.J.1, Kong, B.J.1, Kim, K.1
RESPONSE OF EELGRASS (ZOSTERA MARINA L.) TO OCEAN ACIDIFICATION DURING THE WINTER: A MESOCOSM STUDY
Chonnam National University
A mesocosm study was conducted to evaluate the effects of ocean acidification on Zostera marina(marine flowering plant) over winter period (5 Jan-30 Mar). The mesocosm system was consisted with 9 cylindrical tanks (ca. 1.35 m3), and Z. marina was transplanted into the mesocosm tanks (25-individual in each tank). Target CO2 concentration seawater (ambient: ca. 220 ppm, 2: ca. 440 ppm, 3: ca. 650 ppm) was provided into the tanks with 8 L min-1 water flow rate. Chlorophyll a fluorescence, photosynthesis/respiration, individual production, and growth were obtained after 2 months exposure on each condition. Although the PSII quantum efficiency was not changed under experimental conditions, maximum quantum yield was decreased along the increased CO2 conditions. Photosynthesis and growth rate were slightly increased at 2 CO2 treatment, but Z. marina that grew in 3 CO2 condition was not shown any difference to ambient condition with highest respiration rate. We suggest the Z. marinarequired optimal CO2 concentration for positive responses on photosynthesis and growth, however they could spend more energy to activate photosynthetic apparatus over optimal CO2 concentration.
Kim, T. W.*, Taylor, J., Lovera, C., Barry, J. P.
Ocean acidification impairs olfactory functions in deep sea hermitcrabs but the effects vary between individuals
Monterey Bay Aquarium Research Institute
Future ocean pH is projected to drop considerably at all depths as surface water continues to absorb rising levels of atmospheric CO2 and pH of deep sea water is expected to be lowered by 0.2-0.4 units by the end of this century. Still the possibility if organisms may have an ability to adapt to lower pH has far less explored in deep water species than shallow water species. To test the effect of deep sea acidification on deep sea animals, we compared behavioral and physiological features of the deep-sea (~900m) hermit crab Pagurus tanneri between pH 7.6 (ambient control) and pH 7.1 (low-pH experimental) lab conditions. No significant difference was detected between treatments for some parameters, such as oxygen consumption and the boldness of the crabs, measured as time withdrawn into shell after attack by a potential predator (octopus). At lower pH, however, hermit crabs decreased their rates of antennular flicking (sniffing) and also tended to have a slower speed for prey detection, indicating that lower pH can impair olfactory function. Furthermore, hermit crabs at lower pH showed higher individual variation in antennular flicking rates, prey detection speeds, and respiration rates. This pattern suggests that, although ocean acidification influences some abilities linked to survival in the deep sea environment, the ability to cope with lower pH appears to vary considerably among individuals, potentially promoting population survival by natural selection.
Kindinger, T.L.*, Hixon, M.A.
TO GRAZE, OR NOT TO GRAZE: IT DEPENDS, IS A LIONFISH THERE?
Department of Zoology, Oregon State University
Invasive Pacific lionfish (Pterois volitans) have spread rapidly and abundantly throughout the tropical western Atlantic and Caribbean. These highly efficient predators greatly reduce recruitment of native coral-reef fishes, including juveniles of species important for reef resilience. While invasive lionfish significantly reduce herbivorous fish populations, whether this will have indirect effects on the macroalgal community remains unknown. To address this question, I performed a field experiment in the Bahamas on the effects of lionfish on grazing fishes. At 10 large reefs with low and high lionfish densities regularly maintained since 2009, I observed grazing on replicate algal-covered substrata transplanted from damselfish gardens and measured the following: lionfish presence, grazer abundance, grazing rate, and resulting loss in algal cover. The presence of lionfish had significant effects on both grazer abundance and grazing rates, depending on lionfish treatment as well as the immediate presence or absence of lionfish during observation. However, the resulting loss in algal cover was significantly different only between reef lionfish treatments (and not on immediate lionfish presence). This inconsistent trend could be explained by observed differences in grazer identity, in that lionfish affected the abundance and grazing behavior of parrotfishes more than surgeonfishes, which were distributed differentially among reefs.
Kram, S. L.1*, Donham, E.2, Neu, A. T.3, Hamilton, S. L.2, Price, N. N.1, Smith, J. E.1
OCEAN ACIDIFICATION: CHANGING THE MARINE LANDSCAPE
1 – Scripps Institution of Oceanography, 2- Moss Landing Marine Laboratories, 3- California State University Monterey Bay
Declining oceanic pH associated with Ocean Acidification (OA) is expected to negatively affect growth of calcified algae, but it is unclear how these conditions will impact non-calcifying algae. We conducted a CO2 bubbling experiment with 4 species of common southern California calcifying and fleshy seaweeds. We determined how CO2 enrichment affected algal growth, photosynthetic capacity, carbonic anhydrase activity, pigment concentration, and secondary metabolite bulk chemistry. Ambient seawater conditions were compared to treatment conditions where pH was reduced by 0.2 0.05 units via a constantly bubbling CO2-air blend in continuous flow aquaria. Jania adhaerens, a calcified red alga, had a non-significant slower growth trend in lowered pH treatment (27 days, n=10, p=0.1310) while Dictyopteris undulata, a non-calcified brown alga, grew significantly faster (17 days, n=10, p=.0393). The growth rate of Sargassum filicinum (invasive, non-calcified brown) was not affected (17 days, n=10, p=.5720). Elevated CO2 did not have a significant effect on pigment (Chlorophyll a, Chlorophyll b, carotenoid) content or on the photosynthetic capacities of either Sargassum filicinum or Dictyopteris undulata. Our observations suggest that calcified algae may be less competitive under more acidic oceanic conditions but inter-specific responses among non-calcified algae may vary.
Kroeker, K. J.1*, Gambi, M. C.2, Micheli, F. 3
VOLCANIC CO2 VENTS REVEAL ALTERED RECOVERY DYNAMICS AND VARIABILITY OF BENTHIC COMMUNITIES TO IN SITU OCEAN ACIDIFICATION
1 – Bodega Marine Lab, UC Davis, 2 – Stazione Zoologica Anton Dohrn, 3 – Hopkins Marine Station, Stanford University
Ocean acidification represents a pervasive environmental change that could cause a reorganization of ecological communities, yet little is known about the consequences for ecosystem function. Here, we examine the recovery patterns following a physical disturbance (clearings) of benthic assemblages in ambient, low, and extreme low pH regimes associated with natural, shallow water, volcanic carbon dioxide vents. Our results illustrate how ocean acidification decreases the spatial and temporal variability in community structure at a landscape scale. While the recovery patterns in ambient pH were highly variable and resulted in a range of assemblages, recovery was canalized with acidification, and consistently resulted in very similar algal-dominated assemblages. Reduced disturbance regimes (primarily sea urchin grazing) and increased recovery rates typified the recovery dynamics in low pH. Together, our results suggest that ocean acidification could cause reductions in the habitat patchiness of benthic rocky reef communities in the near future, with cascading impacts on diversity and ecosystem function.
Lee, L.C.*, Salomon, A. K.
TO RUN, HIDE, HOLD ON OR OUT-RUN SLOWER PREY? ESCAPE RESPONSES OF NORTHERN ABALONE TO ALTERED PREDATOR GUILDS
Coastal Marine Ecology and Conservation Lab, Simon Fraser University
Dramatic ecological change has accompanied elimination and subsequent reintroduction of top predators in many marine and terrestrial ecosystems. In relatively exposed temperate rocky reefs of BC, benthic community structure differs remarkably in areas with and without sea otters, a top predator that can drive trophic cascades and influence behaviour of prey species. Natural history observations from three regions of British Columbia highlight varying survival strategies of abalone in response to a suite of coastal and marine predators. Observations suggest that cryptic habitat for hiding is important for abalone when sea otters are present, but that fleeing is a preferred strategy when dealing with sunflower stars, a ubiquitous mesopredator. Laboratory predation experiments suggest that neither the presence of crevice habitat nor slower-moving alternative prey mitigates predation impacts on abalone by sunflower stars on small spatial scales. Understanding how northern abalone respond to altered predator guilds can inform conservation efforts for northern abalone, a species recently uplisted to endangered in Canada.
Lenz, E.A.*, Edmunds, P.J.
THE ROLE OF CORALLUM MORPHOLOGY AND LIGHT MEDIATING THE RESPONSE OF THE CORAL PORITES RUSTO OCEAN ACIDIFICATION
California State University Northridge
Evaluating coral response to ocean acidification (OA) is crucial to understanding how coral reefs will change with reduced pH, yet factors affecting coral susceptibility to OA remain poorly known. Skeletal morphology might be of importance as it affects mass transfer characteristics, modulating the ion flux into tissue necessary for calcification. Theory predicts that corals with dissimilar morphologies exhibit differential calcification responses to mass transfer limitation, potentially occurring at high pCO2. In this study, light-induced morphological plasticity of the coral Porites rus was used to test the role of branching versus plating morphologies in determining susceptibility to elevated pCO2. Following 21d exposure to ambient (40.5Pa) and elevated (81.1Pa) pCO2 at 28C under two light intensities (251 and 1013 mol photons m-2s-1), calcification was similar in branches and plates. However, morphology affected the response to light: for branches, biomass-normalized net calcification increased with light intensity, but plates were unaffected. These results suggest morphological plasticity does not affect the response of corals to OA, presumably because mass transfer did not limit calcification at the high pCO2 and flow conditions we employed. Under high light intensities, morphology might play a stronger role in determining access to soluble metabolites, thereby favoring faster calcification in branches.
Levin, P.S., Rehr, A., Williams, G., Harvey, C.
SETTING TARGETS FOR ECOSYSTEM-BASED MANAGEMENT: A SOCIO-ECOLOGICAL APPROACH
NOAA Fisheries, Northwest Fisheries Science Center
EBM will remain a good idea that is not really implemented until management targets exist. Because targets are an expression of the desired state of the ecosystem, establishing targets must include ecological understanding and societal values. Here, we report on an approach for identifying scientifically rigorous ecosystem targets that explicitly consider social perspectives. Focusing on Puget Sound Partnership, we used a food web model to examine changes to ecosystem attributes that result from simulated changes in nearshore habitat and water quality. We then conducted social norm analyses in which stakeholders were asked to rate the desirability of a range of potential ecosystem futures. By explicating linking trade-offs inherent in socio-ecological systems with societal values, we provide a transparent means for identifying management targets for EBM.
Lewis, J.L.*, Boyer, K.E.
PRESENCE OF A NATIVE ISOPOD REDUCES THE IMPACT OF INVASIVE AMPHIPOD HERBIVORY ON EELGRASS
Romberg Tiburon Center, San Francisco State University
Ampithoe valida is a gammarid amphipod which has invaded San Francisco Bay eelgrass beds. We found this species to have a severe negative impact on eelgrass in both mesocosm studies and field observation. To examine the potential for other species within the eelgrass grazer community to reduce the impacts ofA. valida, we conducted a series of mesocosm experiments. Mesocosm tanks initially contained three eelgrass shoots and a population of one initial grazer species. Initial grazer species were Idotea resecata,Phyllaplysia taylori, Illyanassa obsoleta, and Caprella drepanochir. After 15 days, one eelgrass shoot was collected. Initial species had differing effects on eelgrass mass, mass of epiphytic algae, and chemical composition of eelgrass as compared to the controls. Tanks were then invaded with A. valida and the experiment ran for another 35 days. Tanks containing I. resecata as the initial grazer had significantly greater final eelgrass mass than controls and tanks containing other initial grazers. This reduction in A. valida herbivory impact was not accompanied by a reduction in A. valida numbers, indicating that this is probably an indirect interaction.
Logan, C.A.1*, Dunne, J.2, Eakin, C.M.3 Donner S.D.4
Physiologically derived coral bleaching prediction methods provide a more hopeful outlook for coralS under projected warming
1 California State University, Monterey Bay, 2 NOAA/GFDL, 3 NOAA/Coral Reef Watch, 4 University of British Columbia
Climate warming threatens to increase the frequency of mass coral bleaching events. Using future sea surface warming scenarios from global climate models, previous studies estimated that corals will experience biannual bleaching events by mid-century unless they are able to acclimatize or adapt at a rate of ~0.21.0C per decade. Recent evidence shows that corals have a variety of mechanisms by which they may be able respond to changes in their thermal environment (e.g. symbiont reshuffling, increased thermal tolerance in more variable thermal environments). Whether the magnitude of such responses will match the projected increases in sea surface temperatures is still unknown. Building on previous modeling work and recent studies on the physiology of coral bleaching, we develop several bleaching thresholds, each based on an alternative underlying adaptive mechanism. We use bias-corrected global SST output from the NOAA/GFDL Earth System Model to evaluate the new emissions scenarios for the 5th IPCC Assessment on coral bleaching trajectories. Results provide a range of future bleaching frequencies, some of which dramatically improve the outlook for corals. Physiologically derived bleaching prediction methods refine future bleaching projections, advance population and community modeling efforts, and provide better real-time bleaching alerts to reef managers.
SHORT TERM VARIATIONS IN VERTICAL DISTRIBUTIONS: IMPLICATIONS FOR DETECTING CLIMATE CHANGE
University of California, Santa Cruz
One of the predicted consequences of global climate change, rising sea level, is expected to impact the vertical distribution of intertidal species along the shore. Since 2000, the vertical distribution of the several intertidal species have been monitored along permanent vertical transect lines at several sites in the vicinity of Monterey Bay. Two different methods have been developed to monitor this phenomenon. The first utilizes a series of overlapping pictures taken along the transects to create a visual record of species distributions. The second documents both the region of the shore where each species is spatially common (i.e. zonation patterns), as well as its upper and lower distributional limits. The results show that over the last decade distributions have shifted from tens of centimeters to several meters along the transects. Utilizing topographical measurements of the shore, this translates into vertical shifts that match or exceed the expected magnitude of sea level rise by 2050. This suggests that over the short term, natural variation in species vertical distributions could mask the longer term effects of rising sea level. The effects of local topography will also be discussed.
Longo, C.S.1*, Scarborough, C. 1, Halpern, B.S. 1, Hardy, D. 1, Best, B.D. 1,2, Samhouri, J.F. 3, Doney, S.C. 4, McLeod, K.L. 5
An Ocean Health Index for the California Current
1 – National Center for Ecological Analysis and Synthesis, 2 – Duke University, 3 – National Oceanic and Atmospheric Administration, 4 – Woods Hole Oceanographic Institution, 5 – Oregon State University
Though the California Current is one of the best-studied Large Marine Ecosystems in the world, with a wealth of ecological and socio-economic data sets and routine assessments of fisheries, water quality, iconic species, etc., it still lacks a holistic assessment incorporating all this information. Yet, a synthetic understanding of overlapping human uses and conflicting objectives is the cornerstone of ecosystem-based management. Recently, a new integrated framework, the Ocean Health Index, was used to obtain a global map of the state of all Economic Exclusive Zones. This approach measures the ocean’s ability to provide benefits that people care about both now and in the future. We applied it in the California Current, providing the first data-rich case-study exploring the Index’s potential at smaller scales.
We found relatively high scores, with differences between sub-regions due mainly to habitat condition, fishing pressure and coastal access. Despite being regarded as a data-rich area, we identified key knowledge gaps, such as the lack of regular long-term monitoring of habitats and of other system components needed to accurately describe targets and trends. We also show examples of how different societal objectives, by changing the reference points, can result in different scores.
THE EFFECTS OF SHORE CRABS ON THE MORTALITY, BEHAVIOR, GROWTH, AND DENSITIES OF CALIFORNIA HORN SNAILS (CERITHIDEA CALIFORNICA)
Ecology, Evolution, and Marine Biology, University of California, Santa Barbara
The California horn snail, Cerithidea californica, and the shore crabs, Pachygrapsus crassipes andHemigrapsus oregonensis, are among the most abundant animal species in California and Baja California estuaries. The snail and crabs compete for epibenthic microalgae, whereas crabs can also eat snails and other food items. These trophic interactions are known as intraguild predation and are common in nature despite models predicting that they should be unstable. Using laboratory and field experiments as well as observations on the field we found negative effects of crabs on the population of snails. In the laboratory, we found crabs selected snail eggs and small snails over adult snails. In the field experiments, exploitative competition with crabs, as well as behavioral responses against perceived predation risk (interference competition) caused snails to seek interstitial refugia and reduced snail growth rates. Finally, we found a negative relationship between crab and snail abundances across several estuaries in California and Baja California.
Lowe, A.T1*, Galloway, A.W.E1,2, Sosik E.A.2, Duggins, D.O. 1
Whats in the POM? Variation in biomarkers REFLECTS community composition in suspended particulate organic matter
1-Friday Harbor Labs, 2-School of Aquatic and Fisheries Sciences, University of Washington
Particulate organic matter is the primary food source of marine suspension feeders. In nearshore environments, POM is a complex mixture of many potential sources including living and dead phytoplankton, microzooplankton, terrestrial and macrophyte detritus. However, the composition of POM and use of these disparate components by nearshore consumers is debated. We used a combination of visual quantification of phytoplankton and detritus (20 190 m range), multiple stable isotopes (d13C, d15N and d34S; MSI), and fatty acid (FA) analyses to investigate seasonal and spatial variation of POM in the Salish Sea, Washington. Community composition, MSI and FA were significantly different among seasons, with greater diatom or dinoflagellate abundance in spring and summer, and dominance by detritus in winter. Significant differences existed in community composition, MSI and FA among sampling days within season, but not among sites. d13C and d34S were significantly correlated to temperature, salinity, and chlorophyll concentration (an indicator of phytoplankton biomass). We observed high variability at hourly to seasonal scales; yet in all cases, variation in MSI and FA signatures was related to POM composition. MSI and FA biomarkers thus offer clear potential for describing the POM community and tracking disparate basal energy sources from the POM to consumers.
Lummis, S.C.*, Litvin, S. Y., Micheli, F.
TROPHIC ECOLOGY OF INTERTIDAL INVERTEBRATES IN A SEAGRASS COMMUNITY: SPATIAL AND FUNCTIONAL VARIABILITY
Stanford University, Hopkins Marine Station
Seagrasses provide both structural habitat and an important food resource to a wide variety of marine organisms. However, previous studies have demonstrated that epiphytic algal assemblages residing on seagrasses may be the primary food resources for the organisms residing in these habitats, rather than seagrasses or the detritus they produce. We utilized stable isotope analysis to characterize the importance of food resources for invertebrates residing within intertidal seagrass beds (Phyllospadix scouleri), and to determine how species-specific feeding ecology and wave-exposure mediate the relative importance of these producers. Primary producer 13C values varied between wave protected and wave exposed sites: Phyllospadix scouleri (-13.20 v. -15.42), epiphytic algae (-19.93 v. -21.30), and intertidal algae (-14.72 v. -13.72). All six invertebrate species were isotopically distinct. Certain invertebrates, such as the limpet Tectura paleacea, showed clear differences in isotopic signature between the sites (-14.18 v. -18.60) while the signatures of others, such as the polychaete Lumbrinereis singularisetis, did not vary significantly across the two sites (-17.12 v. -17.24). Differences in signatures among sites and species likely derive from a combination of the differences in wave exposure and changes in the bioavailability of organic matter among sites, along with differences in feeding ecology among species.
Lydon, A.M.1*, Moline, M.A. 1, 2
NEWLY IDENTIFIED ALGA TO THE SVALBARD ARCHIPELAGO: ASSESSING BIOGEOGRAPHIC DISTRIBUTION OFSACCHARINA GROENLANDICA AROUND SVALBARD
1 – California Polytechnic State University (SLO), 2 – University of Delaware
Historical warming events and climate-change in the Arctic have resulted in intermittent colonization of the Svalbard Archipelago (Norway) by organisms from lower latitudes: leading to ecosystem changes. To understand the impacts that species range shifts may have on marine ecosystems, it is essential to establish accurate baseline biodiversity measurements and species distribution patterns. Due to phenotypic plasticity exhibited by many kelp species, identification of algal specimens can be difficult when based solely on morphological characteristics. In this study, we performed DNA barcoding using the ITS and COI-5P (5 end of cytochrome c oxidase 1) sequences to identify algal specimens collected at representative locations around the Svalbard Archipelago. DNA sequence results indicate that many of the samples identified as Laminaria digitata based on morphology are in fact Saccharina groenlandica. This study is the first recorded presence of S. groenlandica in this region of the Arctic. Our further analysis focuses on assessing biogeographic distribution of S. groenlandica around the Svalbard Archipelago and identification of population structuring of S. groenlandica. These results are an important contribution to understanding the distribution of S. groenlandica and future kelp biodiversity assessments in the Arctic.
SHARING IS CARING: IN SHRIMP-GOBY ASSOCIATION, FACULTATIVE MUTUALISTS SHARE PARTNERS BUT OBLIGATE MUTUALISTS DO NOT
Stony Brook University
Mutualist species often compete intra and inter-specifically for the resources provided by their partners. Obligate mutualists rely on these resources more than facultative mutualists do and are consequently expected to compete more strongly for them. Here, I examined interference competition in two goby fishes: Nes longus (an obligate mutualist) and Ctenogobius saepepallens (a facultative mutualist). Both gobies associate with the shrimp, Alpheus floridanus. Shrimp provide gobies with refuge from predators (a burrow in the sand), and gobies provide shrimp with a warning signal when predators are near. With an aquarium experiment, I demonstrated that large N. longus individuals prevented smaller heterospecific and conspecific gobies from using shrimp burrows. In contrast, large C. saepepallens did not exclude smaller gobies of either species. That only N. longus engaged in interference competition is probably due to its greater reliance on shrimp burrows for refuge from predators. Additionally, N. longus maintains guard of shrimp more regularly than C. saepepallens and consequently, forages only in the area immediately outside burrows. In contrast, C. saepepallens forages over a broad area. Thus, differences in competitive ability in the two gobies is probably also related to their different foraging modes.
TEMPERATE REEF FISH DIET AS A FUNCTIN OF SPATIAL AND TEMPORAL VARIABILITY IN BIOGENIC HABITAT AND INVERTEBRATE PREY
University of California, Santa Cruz
Mechanisms that operate across spatial and temporal scales regulate distribution and abundance of available habitat and can influence abundance and diversity of associated fauna. The understory algal community in a kelp forest provides important habitat to a diverse community of small, mobile invertebrates that are important food sources for reef fishes. Morphological complexity of algae can influence the composition and abundance of associated fauna and higher trophic levels. I conducted spatial and temporal surveys of algal habitat and associated invertebrate communities at reefs along the Monterey Bay Peninsula, CA from 2011-2012. Results show matched spatial patterns of both algal and invertebrate communities that are temporally variable. For example, statistically significant relationships exist between communities but only for some months indicating that local drivers may have pronounced effects on the interactions between availability of habitat and structure of associated communities. Habitat-related variability in prey abundance and distribution is known to affect abundance and condition of reef fishes. Gut content analysis was conducted on Oxylebius pictus in summer 2012 to examine variability of diet within a reef. These fish have small home ranges, which will allow for within reef and among reef comparison of diet as a function of foraging habitat availability.
Malm, P.D.*, Nielsen, K.J.
sand grain size and macrophyte wrack: A balancing act between habitat and food for talitrid amphipods?
Sonoma State University, Department of Biology
Natural historians have long observed that the relative abundances of talitrid amphipod species vary predictably among beaches with wave energy and sand grain size. Researchers in southern California have documented that talitrid amphipods are more abundant on beaches with higher abundances of macrophyte wrack. In northern California talitrid amphipod abundance varied by 2 orders of magnitude across 4 beaches within 10 km of Bodega Head. They were most abundant on beaches with finer sand dominated by relatively unpalatable eelgrass and less abundant on coarse sand beaches with abundant kelp wrack. We hypothesized that Megalorchestia burrowing behavior and feeding rates were influenced by the average sand grain size of their habitat, and ultimately influence amphipod population sizes among beaches. We used laboratory experiments to assess burrowing behavior and feeding rates ofMegalorchestia on kelp wrack on 5 different sand grain sizes representative of our study sites. Amphipods unambiguously preferred burrowing and remained inside their burrows longer in finer grained sand. In contrast, they consumed 4 times as much kelp wrack on coarse sand than fine sand. These results suggest there may be high energetic costs to living on beaches with coarse sand that limit the population sizes of talitrid amphipods.
Marks, C. I.1,2*, Foley, M.M.2
CAN BROAD-SCALE HUMAN IMPACT MODELS PREDICT MARINE ECOSYSTEM CONDITION ALONG THE CENTRAL CALIFORNIA COAST?
1 California State University, Monterey Bay, 2 Center for Ocean Solutions Stanford University
Human activities can alter the structure and functioning of marine and coastal ecosystems. To identify the extent and intensity of human uses, cumulative impact models have been produced for a handful of ocean spaces. In 2009 Halpern et al. published the results of a cumulative impact model for the California Current using data on 25 human impacts and 19 marine ecosystems. To examine the feasibility of using this impact mapping approach to inform management decisions, we conducted a groundtruthing study of the model results in two habitats: kelp forests and rocky intertidal. We analyzed ecological monitoring data collected along the Central California Coast to study the relationship between predetermined ecosystem indicators, impact intensity, and cumulative impact score. Our results suggest that sites that had similar abundances of indicator species were also exposed to similar suites of human impacts. We found significant relationships between the percent cover of Corallina spp. and impact score in rocky intertidal areas and density of Sebastes spp. and impact score in kelp forests. Further groundtruthing of this model in additional habitats is necessary to determine the applicability of cumulative impact models to management actions and to predicting changes in marine communities.
Marraffini, M.L.1*, Hamilton, S.L.1, Ruiz, G.M.2., Geller, J. B.1
PROTECTIONS OF NATIVE BIODIVERSITY AGAINST INVASIONS OF SESSILE INVERTEBRATES ON ARTIFICIAL STRUCTURES
1-Moss Landing Marine Laboratories 2-Smithsonian Environmental Research Center
In the face of increasing human population growth, anthropogenic disturbance and climate change, it is important to understand how native communities will be affected by introduced species? Recent surveys have identified over 300 non-native species in California coastal waters, many of which are known to have strong negative impacts on shipping, recreational and commercial fishing, native habitats, and local species. The relative importance of different factors in regulating the success of non-indigenous species are of interest to scientists and managers, yet few multi-factor experiments have been conducted in the marine realm. To examine whether invasion success is more strongly influenced by native biodiversity, available free space, or the presence of other invaders, we manipulated community structure on artificial hard substrates in Monterey Harbor by varying these three factors and tracking changes in recruitment and community structure over a period of several months. Initial results suggest that free space is the most influential factor in the success of introduced species and that biodiversity was not as influential as previously believed. Ultimately, an improved understanding the relationship between native and introduced species is essential to protect ecosystem functioning and native biodiversity.
Marshall, K.N., Kaplan, I.C., Levin, P.S.
VARIABLE IMPACTS OF FUTURE FISHERIES DEVELOPMENT IN THE CALIFORNIA CURRENT ON ECOSYSTEM STABILITY AND BIOMASS DISTRIBUTIONS
NOAA Fisheries, Northwest Fishery Science Center
Demands on coastal oceans continue to rise with the global population. Increasingly, lower trophic level species are targeted for removal because they have been historically under-utilized and form a large proportion of the biomass in food webs. Studies have demonstrated the importance of large biomass forage groups in model food webs, but small biomass contributors are often overlooked. Here, we predict impacts of three potential fisheries targeting relatively low biomass species in the California Current: grenadier (Macrouridae), white croaker (Genyonemus lineatus), and shortbelly rockfish (Sebastes jordani). Using a spatially explicit ecosystem model, Atlantis, we explored fishing scenarios for these groups that resulted in depletion levels of 75, 40, and 25 percent. We evaluated the effects of fishing on ecosystem-wide biomass and spatial distribution of biomass. Results indicate that developing fisheries on the proposed targets would have low impacts on coast-wide biomass of other species. The spatial distribution of impacted functional groups was patchy, and concentrated in the central California region of the model. This work provides a framework for evaluating impacts of new fisheries with varying spatial distributions and suggests that regional effects should be evaluated within a larger management context.
Martone, R.G., Coyle, T.A.*, Nelson, J.C., Demes, K.W., Markel, R.W.
INDIRECT EFFECTS OF SEA OTTERS ON BENTHIC BIODIVERSITY
University of British Columbia
Sea otters (Enhydra lutris) are keystone predators in nearshore kelp forest ecosystems that consume sea urchins and other marine invertebrates, indirectly altering kelp density via urchin abundance. While this trophic cascade is well-documented, less understood are the indirect effects of these changes in kelp, otter and urchin biomass on rocky-reef benthic communities. We investigated the ecosystem-level effects of this trophic cascade by collecting and measuring the biomass and diversity of benthic micro-invertebrates and algae in the kelp forest understory in regions differing in sea otter occupation time along the west coast of Vancouver Island, British Columbia. We found significant differences in seaweed community structure between Kyuquot Sound, where sea otters have been present for more than 20 years and Barkley Sound, where sea otter populations have not yet recovered. Seaweed biomass and species richness were significantly greater in Kyuquot Sound. Invertebrate biomass was three times greater in Kyuquot Sound, but richness did not significantly differ between the two regions. However, invertebrate diversity as measured by the Shannon-Weiner index was significantly greater in Kyuquot Sound. Our results highlight the importance of indirect species interactions in coastal ecosystems, as well as the potential for far-reaching effects in trophic cascades.
Matthews, J.A.1, Jones, C.L.1, Schroeter, S.C.1, Hentschel, B.T. 2
Growth rates of a spionid polychaete vary among sites in a restored wetland
1 – Marine Science Institute, University of California, Santa Barbara, 2 – Coastal and Marine Institute Laboratory, San Diego State University
Many spionid polychaetes readily colonize disturbed sediments and provide trophic support for shorebirds, bottom-feeding fishes, and larger invertebrates. In-situ growth rates can provide valuable knowledge about the population dynamics of spionids as well as help gauge benthic ecosystem functioning. To date, variability in spionid growth rates has been measured in relation to temporal variability, tidal elevation, water flow, and sublethal predation. Spionids in the genus Polydora are a common invertebrate in the newly restored San Dieguito Lagoon, CA (SDL). Within this wetland, tidal inundation, temperature, and salinity vary on a gradient relative to the distance from the tidal inlet. We measured variability in the growth rates of Polydora individuals in relation to these abiotic gradients by transplanting premeasured juveniles on two intertidal mudflats in SDL. Site W1 is a basin in close proximity to the river mouth and site TC7 is a tidal creek located in the rear of the lagoon. Polydora recovered from W1 grew significantly faster than those from TC7. The decreased tidal exchange caused TC7 to have increased water temperatures and highly variable salinity relative to W1. Although a mechanistic understanding requires additional experiments, the data suggest the harsher abiotic conditions at TC7 result in slower growth.
Defending the Castle: The role of diversity in a defensive mutualism
1 Smithsonian Marine Science Network
In 2007-2008, Acanthaster planci ate the fore-reef coral community of Moorea, French Polynesia. We used a series of experiments to determine the efficacy of defense provided by mutualists in response toAcanthaster and two other common corallivores. The Trapeziacoral mutualism protected the host corals through the presence of a diverse and complementary assemblage of crab symbionts. Species frequently differed in their defensive efficacy, but species in similar size classes shared similar abilities. SmallerTrapezia species, which were previously thought to be ineffective guards, play important defensive roles against small corallivores. We measured the benefits of this mutualism to nearby coral species in the midst of an Acanthaster outbreak that reduced the live coral cover on the fore reef to less than 4%. The mutualism positively affects the reef coral demography and potential for recovery during adverse predation events through shelter of multiple species of small corals near the host coral. Our results show that some Trapezia species may be functionally equivalent within the same size class, decreasing the threat of gaps in coral protection caused by absence or replacement of any single Trapezia species.
McPeek, K.C.1*, VanBlaricom, G.R.1,2, McDonald, P.S.1,3, Beauchamp, D.A.1,2
PATTERNS OF UTILIZATION OF GEODUCK AQUACULTURE SITES BY PACIFIC STAGHORN SCULPIN IN PUGET SOUND, WASHINGTON
1 – School of Aquatic and Fishery Sciences, University of Washington, 2 United States Geological Survey, 3 Program on the Environment, University of Washington
Aquaculture operations are a frequent and prominent cause of anthropogenic disturbance to marine and estuarine communities. In Puget Sound, Washington aquaculture of the Pacific geoduck clam (Panopea generosa) is on the rise, however little is currently known about impacts of the industry on ecological communities. Our study took place during the initial phase of geoduck aquaculture that utilizes nets and PVC tubes to protect immature geoducks from predators. We examined the site fidelity, growth and stable isotope signatures of a local ubiquitous predator, Pacific staghorn sculpin (Leptocottus armatus) at geoduck aquaculture sites and nearby reference areas. A mark-recapture study indicated that staghorn sculpin show fidelity to their site of initial capture and grow at different rates in cultured and reference sites. Prior research on sculpin diet showed that types of prey consumed differed by site type. Preliminary results from carbon and nitrogen stable isotope data suggested that sculpin consumption was chemically similar at cultured and reference areas. Future research efforts will focus on improved understanding of predator-prey relationships and growth rates of L. armatus at geoduck aquaculture sites.
Menge, B. A.1*, Menge, D. N. L.2
DYNAMICS OF COASTAL META-ECOSYSTEMS: THE INTERMITTENT UPWELLING HYPOTHESIS AND A TEST IN ROCKY INTERTIDAL REGIONS
1 – Oregon State University, 2 – Princeton University
Meta-ecosystems are defined as ecosystems that are linked by flows of propagules and materials, and offer a conceptual context for global-scale models of ecosystem dynamics. The intermittent upwelling hypothesis (IUH) predicts that the strength of ecological subsidies, organismal growth responses, and species interactions will vary unimodally along a gradient of upwelling from persistent downwelling to persistent upwelling, with maximal levels at an intermediate or intermittent state of upwelling. To test this model, we employed the comparative-experimental method to investigate these processes at 24 wave-exposed rocky intertidal sites in Oregon, California, and New Zealand along a downwelling-upwelling gradient. As predicted, ecological subsidies, prey responses, and species interactions were unimodally related to upwelling, explaining ~53% of the variance in the various processes. These results suggest the IUH has geographic generality, and are also consistent with earlier arguments that bottom-up effects and propagule subsidies are strongly linked to the dynamics of higher trophic levels, or top-down effects, as well as to non-trophic interactions. The ~47 to 53% of the variance not explained by upwelling is likely due to more regional to local influences on the processes examined, and future efforts should focus on incorporating such effects into the IUH.
MOTIVATIONS, MISCONCEPTIONS, AND MANAGEMENT OF COASTAL FISHERIES: A CASE STUDY FROM THE NEOTROPICAL WESTERN ATLANTIC
1 – California Ocean Science Trust, 2 – University of California Berkeley
An understanding of the socioeconomic motivations for harvesting a species and details about its biology are required for effective fishery management. Cittarium pica (West Indian top snail) is a conspicuous, rocky intertidal species that is harvested throughout the Neotropical Western Atlantic. The objectives of this research are to evaluate economic motivations driving the fishery, determine habitat preferences and distribution, and evaluate management policies and misconceptions. I also provide the first detailed documentation of C. pica reintroduction and recovery in Bermuda, from where it was extirpated in <250 years. Results from motivation analyses suggest that high fishing pressure is correlated with: high unemployment and human population density, low GDP and urbanization, high coverage of marine protected areas (MPAs), and lack of enforcement. Evaluation of C. pica habitat preference reveals that, contrary to previous assumptions, it does not exhibit size-specific zonation. Remote sensing of intertidal habitats in Bermuda indicates that accurate habitat mapping requires high-resolution imagery and is scale-dependent. The results of these studies demonstrate that current management practices are generally insufficient to ensure the future of this important fishery. Based on these data, I propose local-scale management strategies for the conservation of C. pica that comprise fishing regulations and targeted MPAs.
Miller, E.F.1, Erisman, B.E. 2*
SPATIAL AND TEMPORAL DEPLETION OF SOUTHERN CALIFORNIA PARALABRAX FISHERIES
1-MBC Applied Environmental Sciences, 2 Scripps Institution of Oceanography
Recreational fisheries for kelp bass (Paralabrax clathratus) and barred sand
bass (P. nebulifer) in southern California have declined substantially to the point of collapse or near-collapse; fisheries landings trends and fishery-independent population data from multiple sources synonymously indicate this. Both fisheries show evidence of serial depletion but at differing spatial and temporal scales. Kelp bass catch per unit effort (CPUE) declined earlier off Los Angeles than San Diego, and CPUE remained high at the Channel Islands long after the mainland areas had declined. For barred sand bass, the spatial contraction of areas supporting intense fishing activity began prior to observed declines in regional catch and CPUE. Year-class strength for kelp bass has been poor since 1982 while the barred sand bass fishery has likely been sustained by the large 1994 and 1997 year-classes. These patterns predicted future fishery success at a 7-9 year lag, consistent with a 5-6 year age at recruitment into the mixed-age fisheries. Our results signify the importance of accounting for spatial and temporal trends in both fisheries and population abundance metrics, especially among pre-recruit age classes.
Miller, S.H.1*, Gaylord, B.1,2, Sanford, E.1,2, Hill, T.M.1,3, Hosfelt, J.1, Russell, A.D.3, K. Laughlin, K.1
RESPONSE TO OCEAN ACIDIFICATION BY A HABITAT-FORMING SPECIES ACROSS A LATITUDINAL GRADIENT
1 Bodega Marine Laboratory, UC Davis, 2 Department of Evolution and Ecology, UC Davis, 3 Department of Geology, UC Davis
Many species worldwide have evolved across large geographic areas, thus exposing distant populations of the same species to a range of diverse environments. In the northeast Pacific, the mussel Mytilus californianus experiences a latitudinal gradient in coastal upwelling. Northern populations have evolved with persistent seasonal upwelling events that bring low pH waters to the surface, while southern populations have evolved under less corrosive conditions. However, these populations are connected to some degree through larval dispersal, leaving open the question of whether local adaptation to acidification stress could have arisen. To test whether populations across this latitudinal gradient might respond differently to ocean acidification, we spawned adults from seven sites along the west coast of the U.S. and raised their larvae in common garden experiments representing current (385ppm) and projected future (1000ppm) pCO2 levels. Measurements of larval shell surface area, tissue mass, and survivorship revealed that larvae from multiple sites responded negatively to decreases in ocean pH. These similarities in response across a latitudinal gradient suggest that populations in regions with periodic corrosive events will not necessarily be more resilient to ocean acidification than nave populations, showing that future decreases in ocean pH could have dramatic consequences across species ranges.
Moen, D.*, M. Stakes, K.J.Sorenson, J. Burnett
SURVIVAL AND MORTALITY OF A REINTRODUCED CALIFORNIA CONDOR
POPULATION IN BIG SUR, CALIFORNIA.
Ventana Wildlife Society
The California Condor (Gymnogyps californianus) population historically experienced severe losses, prompting the complete removal of the species from the wild in 1987. A successful captive breeding effort allowed reintroduction of captive-born condors in southern California starting in 1992. Starting in 1997, Ventana Wildlife Society released 47 condors in Big Sur, California. Seventeen (36%) released condors died in the wild in 1997-2010. We calculated an overall annual survival of 93.3%; slightly higher than survival reported for condors in Arizona in 1996-2005. Annual survival was 83.5% for condors in the first year following release and 97.0% for condors 5 years following release. Power lines and lead were the leading sources of mortality, although mitigation efforts have reduced the power line threat in recent years. Six condors were treated by chelation therapy for lead levels 100 g/dL. Under a hypothetical scenario of fatality at lead levels 100 g/dL, annual survival dropped to 89.9%. Treatments may have improved survival, and the 2008 ban of lead ammunition in Californias condor range is expected to reduce future risk of lead exposure. Establishment of a viable, self-sustaining population will depend on a low level of exposure to lead.
PARAMETERIZING A DYNAMIC ENERGY BUDGET MODEL FOR THE KEYSTONE PREDATOR PISASTER OCHRACEUS
University of South Carolina
By driving prey dynamics, keystone predators can define the structure and functioning of entire communities. Mechanistic studies have shown that the relative importance of predator species on their communities is largely determined by their sensitivity to varying body temperature and food conditions. Despite widespread recognition of keystone predators critical ecological role, few predictive frameworks have been developed that account for interactive effects of varying prey availability and temperature on their physiological condition. Pure experimental studies are usually unable to capture the interaction of multiple environmental variables. Pure theoretical approaches, in turn, consider inherently complex environments, but are often criticized for lacking realism. By merging these approaches, current efforts are providing a deeper understanding of the ways in which individuals physiological condition varies under constantly fluctuating environmental signals. Dynamic Energy Budget (DEB) models rise as powerful tools, capable of integrating such signals to shed light on the organisms fitness throughout its life-history. I show work-in-progress aimed towards estimating standard DEB parameters for the keystone predator Pisaster ochraceus. Besides relying on computer simulations and literature surveys, the model parameterization is strongly supported by empirical observations. Preliminary outputs are shown, where Pisasters foraging behavior and fitness are contrasted under different temperature and food conditions.
Montgomery, E. M., Palmer, A. R.
EFFECTS OF BODY SIZE ON LOCMOTION OF NORTHEAST PACIFIC SEA STARS
University of Alberta, Bamfield Marine Sciences Center
Larger animals tend to move faster in most animal taxa independent of mode of locomotion. Increased body size allows a greater surface for muscle attachment and increased stride length as longer limbs can move farther in each step or stroke. Within the class Asteroidea (sea stars), however, this trend is not as clear. This group uses highly conserved, hydraulic tube feet for propulsion yet not all species examined thus far exhibit the general trend that larger bodied animals move at faster speeds: the blue star Linckia laevigata crawls the same speed independent of body size and larger individuals of the bat star Patiria miniata actually crawl slower than smaller ones. Why larger sea stars move more slowly remains a puzzle, so further study of the tube feet / crawling mechanism is needed. Preliminary crawling data for the striped sun star Solaster stimpsoni, the leather star Dermasterias imbricata, and the sun star Pycnopodia helianthoides extend our counterintuitive results to sea stars from three different orders.
Morgan, S.G.1, Shanks, A.2, MacMahan, J.3, Reniers, A.4, Brown, J.3 Griesemer, C. 1
DIFFERENTIAL TRANSPORT ACROSS THE SURF ZONE OF REFLECTIVE AND DISSIPATIVE SHORES AS A DETERMINANT OF LARVAL SUPPLY
1 – Bodega Marine Laboratory, 2 – Oregon Institute of Marine Biology, 3 Naval Postgraduate School, 4 – University of Miami, 3 Naval Postgraduate School
We determined whether differences in water exchange across the surf zone on dissipative and reflective shores regulates larval supply to intertidal populations. We surveyed zooplankton daily for one month relative to physical conditions inside and outside the surf zone at a dissipative and reflective beach near Monterey, California. Larvae of some species completed development nearshore while larvae of other species migrated offshore and back. Concentrations of zooplankters were much greater outside than inside the surfzone at the reflective beach, indicating that the surf zone may block onshore transport. Barnacle cyprids were an exception, suggesting that ontogenetic changes in larval behavior may facilitate penetration of the surf zone. In contrast, zooplankters were 1 to 2 orders of magnitude more concentrated inside the surf zone of the dissipative beach. Settlement of barnacles on rocks at both beaches was low, and settlement of sand crabs, Emerita analoga, was abundant only on the dissipative beach. Different hydrodynamics of surf zones at dissipative and reflective beaches together with larval behavior may play a major role in regulating larval supply along the West Coast.
Morrison, R.A.* Sandin, S.A.
TRENDS IN CORAL REEF HEALTH IN A NEW SOUTH PACIFIC MARINE PARK
Scripps Institution of Oceanography, UCSD
The newly declared 1.1 million km2 Cook Islands Marine Park in the south Pacific, covering approximately 60% of the Cook Islands Exclusive Economic Zone (EEZ), sets a precedent for the establishment of large marine protected areas in remote Pacific island nations. The collection of ongoing monitoring data is critical in evaluating the success of such areas. However, many of the coral reef systems of the Cook Islands are relatively little-studied. To address this research gap, I conducted preliminary surveys of reef fish and benthic community structure at three of the Cook Islands (Rarotonga, Aitutaki, Penrhyn) prior to the establishment of the marine park. Here, I evaluate trends in coral reef ecosystem health at each of these islands in the context of variations in local human population and proposed zoning of the marine park. As seen in other remote Pacific island systems such as the Line Islands, indicators of reef health, such as higher fish biomass and higher percent cover of calcifying organisms, were related to lower human population levels. These baseline data can provide a dynamic indicator of reef condition, which can be used to inform management of both the Cook Islands Marine Park and other protected areas.
Morton, D.N.1,2*, Shima, J.S.1
Habitat configuration and availability influences the settlement of temperate reef fishes (Tripterygiidae)
1 – Victoria University of Wellington, 2 – University of California, Santa Barbara
Temperate marine macroalgal systems are naturally dynamic, and are also subject to anthropogenic fragmentation and habitat loss. Relatively little is known about the role of landscape structure in these systems, and observational studies are typically unable to distinguish between habitat loss and fragmentation per se. We examined the role of habitat configuration and availability in the settlement of New Zealand triplefins (Triterygiidae) in a field experiment utilizing artificial habitat units. Three treatments were constructed, which allowed us to separate the effects of habitat loss and fragmentation. Addition of habitat resulted in higher total settlement at the level of the entire habitat patch, but the magnitude of increase depended on the landscape configuration: the highest settlement occurred to continuous habitat patches. Fragmented, patchy habitat received lower settlement per unit area than both large continuous patches and small isolated patches, suggesting potential local limitation of settlement stage larvae. Continuous patches may provide a stronger settlement cue, or may represent a higher quality habitat for recently settled triplefins. Our findings provide some evidence for habitat limitation, but it appears that the landscape architecture, in addition to the total amount of available habitat, is an important determinant of settlement success for triplefins.
Moskal, S.M.1,2*, Takekawa, J.Y.1, Brand, L.A.1, Shaffer, S.A.2
if you build it, will they come? Wintering and Migrating Shorebird Responses to Enhancement Efforts in a wetland habitat
1 – U.S. Geological Survey, Western Ecological Research Center, San Francisco Bay Estuary Field Station, 2 – Department of Biological Sciences, San Jose State University
The salt ponds of the San Francisco Bay are important to large numbers of migrating and wintering waterbirds. The South Bay Salt Pond Restoration Project proposes to convert 50 to 90% of the 6100 ha of former salt ponds to tidal marsh. A major challenge is to maintain the abundance of non-breeding waterbirds in a smaller footprint of managed ponds. Possible ways to maintain abundance are through pond enhancements such as water control structures and island construction. During 2009-2010, Pond SF2 was enhanced with 30 islands and restored to tidal flow regulated through water control structures. To assess how non-breeding waterbirds responded to these enhancements, we surveyed birds weekly from October 2010 May 2012. Preliminary results indicate that 14% of non-breeding waterbirds observed in the pond used the islands. Foraging guilds used the islands unequally: 50% of piscivores and 10% of small shorebirds were observed on islands. However, if pond bottom was exposed via water level manipulations when high tides covered the mud flats, 19% of all small shorebirds were observed foraging and 34% were roosting on the pond bottom. Thus, exposure of the pond bottom may be more important for non-breeding shorebirds than is the availability of islands.
Munday, E.S.1*, Heidel, J.R.2, Miller-Morgan3, T., Tissot, B.N.1
EFFECTS OF COLLECTION, TRANSPORT, AND HOLDING PRACTICES ON YELLOW TANG (Z. FLAVESCENS) HEALTH, STRESS, AND LONG-TERM SURVIVAL
1- Washington State University Vancouver 2- Oregon State University Veterinary Diagnostic Laboratory 3- Oregon State University Hatfield Marine Science Center
We conducted an experiment in cooperation with fishers and exporters in West Hawaii to determine the effects of collection, transport, and holding practices on mortality and sublethal effects in live ornamental aquarium fish. Yellow tangs were subjected to two different decompression rates (fast: 0.5ms-1, intermediate: 45min. at 6m) and venting treatments (yes, no) in a blocked orthogonal design, held in an export facility for the standard industry duration, transported by air from Kona, HI to Portland, OR, and held for 6 mos. at the Hatfield Marine Science Center in Newport, OR. We recorded fish mortality and examined sublethal effects using histology, bacteriology, and plasma cortisol (a proxy for stress). Water quality was monitored in the experimental export facility, as well as in other local export facilities. Our findings indicate that practices implemented by aquarium fishers and exporters in West Hawaii do not cause significant rates of mortality, or produce significant sublethal effects that could lead to delayed mortality in this species. These results may guide management decisions in West Hawaii, and the effective methods may be applied in regions where aquarium fish collection has been documented to incur high fish mortality.
Muthukrishnan, R., Lloyd-Smith, J.O., Fong, P.
INTEGRATION OF EMPIRICAL AND SIMULATION METHODS TO EVALUATE ALTERNATE STABLE STATES ON TROPICAL REEFS
University of California Los Angeles
Recent attention has been placed on the idea that dramatic community shifts represent shifts between alternative stable states (ASS), though robust evidence is lacking. We tested ASS theory on two Panamanian reefs by identifying positive feedback processes that could produce ASS. Using in situ assays of algal consumption, growth and nutrient limitation we identified two mechanisms (coral facilitation of herbivory and algal facilitation of nutrient availability) that showed positive feedbacks with community composition. In a coral-dominated state herbivory rates were higher, algal growth was lower and nutrient limitation was stronger than in an algal-dominated state. Using these mechanisms we developed a spatially explicit simulation model of competition for space between coral and algae. The presence of positive feedback mechanisms alone drove rapid shifts between community states and generated hysteresis in the model by producing separate basins of attraction around coral-dominated and algal-dominated community states under a range of intermediate environmental conditions. Each state persisted over long timescales, indicating positive feedbacks can be sufficient to stabilize each state. In addition, with positive feedbacks, coral and algae in the model would segregate to separate regions of the model space producing sharp boundaries. This accorded with previous theory and observational surveys of benthic community composition that showed reefs were segregated into distinct patches dominated by either coral or algae. As our model results show that positive feedbacks can be sufficient to produce and stabilize alternate community states, identifying such mechanisms should be considered a valuable initial diagnostic criterion for identifying possible ASS dynamics.
Nelson, J.C.1*, Harley, C.D.G.1, Therriault, T.W. 2
ENVIRONMENTAL CONDITIONS AND SPECIES INVASION INTERACT TO AFFECT THE NATIVE FOULING COMMUNITY
1 – University of British Columbia, 2 – Fisheries and Oceans Canada
Species invasion and climate change are two of the most important threats to the environment, and the interaction of these stressors may have serious consequences for native biodiversity. We surveyed 24 ports that differ in temperature and salinity, but that are otherwise similar, along the coast of British Columbia. In order to evaluate their ecological effect, half of the ports were selected for presence of botryllid tunicates while other half were selected for absence. The natural gradients in temperature and salinity informed a prediction of the effect that climate change will have on biodiversity. The percent cover of native species on settlement plates did not predict the presence of non-indigenous species (NIS). However, when NIS were present, NIS and native species cover were negatively correlated. Higher NIS cover was found in areas with higher, more stable salinity and temperature. The cover of native species was only affected by salinity range when botryllid tunicates were present. The presence of botryllid tunicates also reversed the relationship between native cover and minimum temperature. Our study provides an understanding of multiple stressors on a regional scale using field data, while gathering information on important NIS that could have greater impact as climate change progresses.
Newcomb, L.A.1,2*, Carrington, E.1,2, George, M.N.1,2, ODonnell, M.1
EFFECTS OF SHORT-TERM EXPOSURE TO ELEVATED TEMPERATURE AND pCO2 ON MUSSEL BYSSAL THREAD STRENGTH
1 Friday Harbor Laboratories, 2 University of Washington, Department of Biology
Mussels tether themselves to rocky substrates with extracellular collagenous byssal threads to resist dislodgement from waves and predators. Previous studies show seasonal trends in thread strength, where thread weakening in summer/fall leads to increased mussel dislodgement. We have identified elevated temperature and pCO2 as two of the many potential environmental factors that weaken threads. These two stressors affect different regions of the threads, with temperature weakening the proximal region and pCO2 the plaque. Because these thread regions act in series, the effects of elevated temperature and pCO2 will not be additive, but rather one factor will be dominant. We tested the hypothesis that at high temperatures, temperature is responsible for thread weakening with minimal effects of pCO2, but that at cooler temperatures, high pCO2 conditions will weaken threads. Field collected mussels (Mytilus trossulus) were acclimated to their temperature conditions prior to producing threads in temperature and pCO2 controlled aquaria for three days. Mussels in 25C took longer to, and produced fewer threads than mussels at cooler temperatures. These threads were half as strong as threads in cooler temperatures and more likely to fail at the proximal region. There were no measurable effects of pCO2 on thread strength, number, or hours to attach. Short-term temperature changes may be a factor causing dislodgement whereas short-term pCO2 changes are not.
Newsom A*, Scianni, C., Brown, C., Dobroski, N., Nedelcheva, R., Falkner, M.
Geographic patterns of ballast water exchange and discharge to San Francisco Bay-Delta region
California State Lands Commission, Marine Invasive Species Program
Under current regulations, the California State Lands Commission (Commission) collects and manages ballast water reporting forms from vessels arriving in California. These forms contain a rich data source regarding ballast water management practices, including ballast water exchange locations for vessels arriving to the San Francisco Bay region, which is an area of particular interest as it is among the most invaded estuaries in the world.
This presentation comprises an analysis of ballast water discharged to San Francisco Bay and the Sacramento-San Joaquin River Delta region for the past two years, in the context of a changing regulatory landscape, using the Commissions ballast water management form database. Where and when ballast water has been taken up, exchanged, and discharged within the waters of San Francisco Bay and Delta, and trends in vessel compliance with exchange requirements will be presented. This information is a powerful tool for retrospective and predictive analyses of marine invasion patterns in the San Francisco Bay region.
Nickols, K.J.1*, White J.W.2, Malone, D.P.3, Carr, M.H.3, Botsford, L.W.1, Barnett, L.A.K.1, Baskett, M.L.1, Hastings, A.1
DETECTING EFFECTS OF MARINE PROTECTED AREAS ON FISHED SPECIES: AN INTEGRATED APPROACH USING POPULATION MODELS AND MONITORING DATA
1 University of California, Davis, 2 University of North Carolina, Wilmington, 3 University of California, Santa Cruz
Marine Protected Areas (MPAs) are often designed to increase abundance and size of fished species. These effects may take years to manifest, and initial responses may differ from long-term outcomes, which should be taken into account when evaluating MPAs using short-term (e.g., 5 years) monitoring data. We expect MPAs to produce changes in the size distribution (as older, larger fish survive longer) and later, in total abundance (as new recruits enter the population). We analyzed size-frequency distributions of blue rockfish from monitoring data from Central California to assess short-term responses to MPAs implemented in 2007. For most years, there was no difference in total abundance of fish greater than the minimum length fished, nor was there a difference in mean size, between sites inside and outside reserves. This suggests that either (a) MPAs did not reduce fishing inside boundaries, (b) there was little fishing at sites before MPA implementation, or (c) there is too much variability in the dataset to detect MPA effects. We evaluated these possibilities using an Integral Projection Model fitted to size-structured data. Our analysis reveals the potential limitations of monitoring data and the need for spatially explicit information on fishery effort when evaluating MPA performance.
Nielsen, K.J.1*, Gouhier, T.C.2, Menge, B.A.2, Chan, F. T.2, McPhee-Shaw E.E.3, Largier J.L.4, Raimondi, P.T.5
Synoptic forcing and local scale dynamics of surfzone phytoplankton in the northern California Current Ecosystem
1 – Sonoma State University, 2 – Oregon State University, 3 – Moss Landing Marine Laboratories, 4 – Bodega Marine Laboratory, 5 – University of California, Santa Cruz
We used 9 years of daily fluorometer-based chlorophyll-a measurements at 14 sites in Oregon and California spanning 8 degrees of latitude to investigate coupling between offshore (remotely sensed) and surfzone chlorophyll-a, and variation across large spatial domains and years of varying climatic conditions as indexed by SST, indices for local upwelling, MEI, PDO and NPGO. We assessed intra-annual variability, phenology and larger spatio-temporal patterns using time-series and multivariate statistical tools. We found strong gradients in chlorophyll-a concentration and variability with distance from shore (negative) and latitude (positive). Surfzone and remotely sensed chlorophyll-a were correlated among years, but the relationship changed with distance from shore. Local-scale physical forcing explained more variance in surfzone chlorophyll-a at northern sites, while ocean-scale forcing had more explanatory power for southern sites. Bloom phenology varied: a single high chlorophyll-a period in mid-late summer characterized northern sites, while southern sites had a bimodal or single early peak. Our results highlight the role of ocean-scale physical forcing in the surfzone, but also its variable expression among regions. High surfzone chlorophyll-a relative to shelf waters across this domain reflects a growing body of evidence that nearshore waters are characterized by distinct physical and biological properties that challenge existing paradigms.
FINDING NEMO USING CITIZEN SCIENCE: DISTRIBUTION AND HOST SPECIFICITY OF ANEMONEFISHES
University of California Santa Cruz
Understanding the distribution of species and species interactions is a central goal of ecology and evolutionary biology. However, comprehensive accounts of species distributions are often time and cost prohibitive. As online social networking and photo sharing becomes increasingly pervasive, users are providing a large amount of information which can be harvested and used by scientists. I used the Flickr API to gather thousands of geo-tagged photos of anemonefishes from across the range of all species. I then identified the fish in each photograph, along with the anemone with which it was associated. These records were overlaid onto a GIS database of coral reef distributions, allowing the estimation of habitat availability and distribution for each species. I found that range size, habitat availability, and host use varied greatly across species, and that patterns of host use varied within species across the geographic range. These results provide evidence of vast variation in range size across a recent radiation of species, support a geographic mosaic model of interaction between the fish and host species, and demonstrate the utility of this method of data collection.
Paddack, M.J.1,2*,Crane, N.L.1,3, Bernardi, G.4, Abelson, A.5, Crosman, K.6, Nelson, P.7, Precoda, K.1
INITIAL ecological assessment of shallow reefs of Ulithi Atoll, Federated States of Micronesia
1-Oceanic Society, 2-Santa Barbara City College, 3-Cabrillo College, 4-University of California Santa Cruz, 5- Tel Aviv University, 6-University of Michigan, 7-CFR-West
On Ulithi Atoll, Micronesia, concern with declining fisheries and coral reef health led the Chiefs of Falalop to invite our team to survey their reefs and help craft a sustainable marine resource use plan. By incorporating social science, quantitative ecological assessments, and community education, we are working in close partnership with the islanders to create a plan that fits into their needs and customs. Our first visit (July 2012) revealed strong differences among Ulithian reefs. Despite their remoteness and limited development, most sites had <20% live coral cover dominated by small colonies. A few had >60% cover, but with unprecedented overgrowths of a single coral species. Initial findings suggest that these outbreaks may limit habitat and food for key reef organisms. Additionally, we found 100x difference in fish biomass among some reefs, driven by high variation in herbivorous and predatory fishes. Interview results suggest that fishing practices may be strong drivers of changes in both benthic and fish communities. The community of Falalop has incorporated these findings into an initial reef management plan which was immediately implemented. We continue our work with these island communities to determine major drivers of declines and evaluate the effectiveness of changes in resource use.
Perini, V.C. *, Bracken, M. E. S.
CO-LIMITATION ON NEW ENGLAND ROCKY SHORES: THE IMPACT OF NUTRIENT ENRICHMENT ON SEAWEED GROWTH, TISSUE QUALITY AND UPTAKE KINETICS
Northeastern University Marine Science Center
Variation in access to and availability of nutrients can mediate ecological processes on rocky shores. In the Gulf of Maine, seasonal fluctuations and weather related events create variation in ambient nutrient levels, which can influence seaweed growth and transfer of nutrients to higher trophic levels. Observations of tissue nutrient content, of the seaweed Fucus vesiculosus, revealed that this seaweed may not be able to absorb available phosphorus without sufficient nitrogen. To test these observations, we performed an enrichment experiment from July to August of 2012, in outdoor water tables with flowing seawater. F. vesiculosus were enriched with N, P, N&P (or given no added nutrients as a control treatment) for 6 weeks, and seaweed growth was measured weekly throughout the experiment. Enrichment treatments did not impact seaweed growth, indicating that seaweed were not nutrient limited at the start of this experiment, despite low ambient nutrient levels. In fact, seaweed enriched with N alone grew less than other treatments, although this difference in growth was not significant. These results highlight the context-dependency of nutrient limitation in marine systems and emphasize the need to consider multiple factors when assessing the impacts of nutrient availability on rates of primary productivity.
Picard, M.1*, Harley, C.D.G.1, McClelland, E.K.2, Miller, K.M.2
THE EFFECTS OF INCREASED pCO2 ON EARLY DEVELOPMENT OF OYSTER, (CRASSOSTREA GIGAS): CRITICAL THRESHOLD AND ACCLIMATION
1 – University of British Columbia, 2 – Fisheries & Oceans Canada
Ocean acidification has many negative effects on marine organisms especially on calcifying species. Due to the economicimportance of the latter, research has already been undertaken to determine the extent of the effects however, little is known about the effects at early developmental stages. Therefore, we investigated which early developmental stage of oyster (Crassostrea gigas) is most vulnerable to highpCO2 levels and whether larvae grown in high pCO2 demonstrate signs of acclimation. Conducting this study under aquaculture setting, we measured growth, feeding rate as well as shell strength and condition of the individuals at low (350-450 ppm) and high (650-750 ppm) pCO2 levels. Our study could provide hatcheries with a better yield by determining the pH levels at which chemical interventions must be employed. In the long term, a better insight in the effects of ocean acidification in the development of shellfish could provide managers with a tool for restoring stocks that are negatively impacted in the wild.
Pinheiro, H.T.1*, Martins, A.S.2, Joyeux, J.C.2
The importance of small-scale environment factors to community structure patterns of tropical rocky reef fishes
1 University of California Santa Cruz, 2 Universidade Federal do Esprito Santo
Understanding the spatial distribution of fish species and fish trophic guilds in reef environments may help improve our knowledge of ecological relationships and therefore favouring sound strategies for sampling, coastal management and conservation policy. To verify if small-scale changes are important in structuring the fish community structure at a tropical rocky coastal island, we assessed the depth, structural complexity and wave exposure gradients. The community structure changed along all gradients analysed. The trophic guilds found on the sheltered, low and intermediate exposure zones, in the deepest areas and in areas of highest structural complexity showed significant differences when compared with the general assemblage. Rocky reefs, even of narrow (transversal) extension, can show great changes in fish community structure at so small a scale that these changes are generally overlooked. The relationships evidenced between community and environment provide strong support for the importance of considering a wide array of such distinct environmental conditions when determining the structure patterns of the community.
Porturas L.D.*, Long J.D.
SIZE DOESNT MATTER: SMALL HERBIVORE HAS LARGE IMPACT ON PERFORMANCE OF SOUTHERN CALIFORNIA SALT MARSH CORDGRASS, SPARTINA FOLIOSA
Coastal and Marine Institute Laboratory, San Diego State University
In contrast to Atlantic salt marshes, top-down control of primary production is rare in Pacific marshes suggesting that either the ecology of these systems differs dramatically with geography or that top-down control may have been underestimated because key herbivores have been overlooked due to their size. We investigated the influence of a tiny (<3mm), yet common, herbivorous scale insect on the performance of Pacific cordgrass (Spartina foliosa) – a dominant salt marsh plant. We conducted a 20-week field experiment in South San Diego Bay where Spartina stems were maintained as Scale or No Scale treatments by manual scale insect removals and Spartina performance characteristics such as growth, survivorship, and seed production were monitored. Presence of scale insects reduced plant growth (e.g. total leaf length and biomass) and survivorship but had no significant impact on seed production, although a negative trend was present. Our results suggest scale insects have the potential to be important players in Southern California salt marsh community structure. Such a discovery is timely given that the distribution of these herbivores has recently expanded throughout southern California marshes and scales may impede the success of salt marsh restoration strategies that rely on high survivorship of cordgrass transplants.
Price, N. N.1*, Rohwer, F. L.2, Sandin, S. A.1, Andersson, A.1, Smith, J. E. 1
BENTHIC METABOLIC FEEDBACKS TO CARBONATE CHEMISTRY ON CORAL REEFS: IMPLICATIONS FOR OCEAN ACIDIFICATION
1 – Scripps Institution of Oceanography, 2 – San Diego State University
The metabolic activity of resident reef organisms contributes to spatio-temporal variability in carbonate chemistry and thus can potentially buffer against ocean acidification. We encapsulated replicate areas (~3m<sup>2</sup>) of reef across six Northern Line Islands in the central Pacific for 24 hrs to quantify feedbacks to carbonate chemistry from benthic assemblages. We coupled high temporal resolution time-series data for pH, dissolved oxygen, salinity, and temperature (using autonomous sensors) with resident organisms net community calcification and productivity rates (using the total alkalinity anomaly method). These reefs experienced large ranges in pH (> 0.2 amplitude) each day, similar to the magnitude of acidification expected over the next century. Diurnal amplitude in pH, pCO<sub>2</sub>, and <sub>aragonite</sub> at each island was related to the biomass, productivity, and calcification rate ofHalimeda. Net primary productivity of fleshy algae (algal turfs and Lobophora spp.) predominated on degraded, inhabited islands where net community calcification was negligible. In contrast, the chemistry over reefs on pristine, uninhabited islands was driven largely by positive net calcification of calcareous algae and stony corals. Knowledge about relative abundances of key taxa whose metabolism significantly alters carbonate chemistry may give insight to the ability for a reef to buffer against or exacerbate ocean acidification.
Putnam, H.M.*, Gates, R.D.
CLIMATE CHANGE AND PARENTAL EFFECTS IN SPAWNING CORALS
Hawaii Institute of Marine Biology
Coral reefs are highly productive and diverse ecosystems under threat both locally and globally. Increasing seawater temperatures and ocean acidification (decreased pH and altered carbonate chemistry) have detrimental effects on corals, and the severity of these stressors is predicted to increase in the future. It is possible, however, that corals may exhibit parental effects, thereby influencing the trajectory of their offspring. To examine the simultaneous effect of these stressors on reproductively active corals and their eggs, adult Montipora capitata fragments (n=48) from Kaneohe Bay, Hawaii were exposed to ambient (26C, ~460atm), or high (29C, ~855atm) treatments for one month prior to spawning. Following the exposure, adult corals were assessed for spawning activity, time of release, egg size, number of eggs and egg biomass per coral. Reproductive timing was shifted, with a higher proportion of colonies releasing egg-sperm bundles earlier under high treatment. Egg size was reduced by ~25% in the high treatment, however, total reproductive biomass was maintained at statistically equal levels with higher numbers of smaller eggs released under high treatment, and fewer larger eggs released under ambient treatment. Together, these results suggest increased temperature and ocean acidification drive parental effects that will modulate offspring fitness.
QUASARS TO SEA STARS GIVING TEENS THE INSIDE SCOOP ON WHAT IT TAKES TO BE SCIENTIST
Santa Barbara Museum of Natural History
Science education excels when hands-on experiences and field excursions are included to expand typical lecture based education. At the Santa Barbara Museum of Natural History we have taken it a step further and involve selected teens in every aspect of our Natural History Museum. The Quasars to Sea Stars program is a four-year teen science program that takes public school students with an interest in the natural world and immerses them in natural history and Museum life. The teens take summer courses at the Museum, work alongside Museum staff, and are employees that work in all departments of the Museum. Teens learn about science and collections by participating in science discovery, curatorial tasks, and gain understanding of the importance of collections. But their science experience doesnt stop at collections. The teens are engaged in exhibit design, public education, development, marketing, and public relations. This program is presented to inspire scientists and educators to include their students in multiple aspects of their science and become involved in educational programs outside of their school districts.
Reeve, L.D.*, Hovel, K.A.
CAN EELGRASS SERVE AS A NURSERY HABITAT FOR CALIFORNIA HALIBUT?
San Diego State University Coastal and Marine Institute Laboratory
Structured habitats such as seagrasses provide juvenile fishes with refuge from predation and support high densities of their prey. Studies of juvenile fishes in seagrass have primarily focused on canopy-dwelling species, whereas few studies have considered nursery requirements for commercially important benthic flatfishes such as halibut that may have different predator avoidance and foraging strategies than non-flatfishes. We conducted field experiments to determine (i) whether juvenile California halibut (Paralichthys californicus) prefer eelgrass (Zostera marina) to unvegetated sediment, and (ii) how relative survival of juvenile halibut varies between unvegetated sediment and eelgrass and with proximity to the eelgrass edge. Juvenile halibut displayed a strong preference for eelgrass habitat in predator exclusion cages spanning an eelgrass-unvegetated sediment interface. Our tethering experiments compared relative survival among four sub-habitats: (i) unvegetated sediment, (ii) eelgrass patch edge, (iii) eelgrass patch interior, and (iv) eelgrass patch interior with eelgrass shoots thinned to a density comparable to the low shoot density characteristic of the edge. Halibut survival was lowest at the eelgrass patch edge and highest in the low-density eelgrass patch interior. However, survival was higher in unvegetated sediment than in high-density eelgrass. Our preliminary results suggest a complex relationship exists between juvenile halibut and eelgrass habitat.
Reimer, J. N. *, Hacker, S.D., Menge, B.A.
DRIFT ALGAE AS AN ECOLOGICAL SUBSIDY ON SANDY SHORES: VARIATION ALONG THE UPWELLING GRADIENT OF THE OREGON COAST
Oregon State University
Drift macroalgae and seagrass, also known as wrack, which wash into coastal habitats may be important contributors of nutrients, organic matter and physical structure for coastal communities. These ecological subsidies seem to be especially important on sandy beaches, where there is otherwise little in situprimary productivity to fuel higher trophic levels. Since stronger upwelling should deliver more nutrients to algal dominated rocky habitats, macrophyte primary production could potentially be higher in areas of more intense upwelling, and thereby provide higher wrack input to nearby sandy shores. We tested this hypothesis by conducting surveys to measure macrophyte percent cover and biomass at three sites that differ in upwelling intensity along the Oregon coast. Preliminary analyses indicate that sandy beaches with strong upwelling (Cape Blanco, OR) receive a greater amount of wrack than beaches with intermittent upwelling (Boiler Bay, OR and Strawberry Hill, OR). This suggests that regional differences in productivity due to ocean upwelling and the proximity to rocky intertidal habitat can influence the amount of wrack delivered to beaches. Given this pattern, future research will explore how far wrack subsidies penetrate inland, the mechanism of transfer, and the ultimate influence that these subsidies have on coastal food web dynamics.
Rose, J.M. 1*, Blanchette, C.M. 2, Raimondi, P.T. 3, Sanford, E. 4, Williams, R.C. 3, Menge, B.A. 1
THE RELATIVE INFLUENCE OF UPWELLING-DRIVEN OCEAN ACIDIFICATION ON IN SITU GROWTH OF THE CALIFORNIA MUSSEL, MYTILUS CALIFORNIANUS
1 Oregon State University, 2 – University of California Santa Barbara, 3 – University of California Santa Cruz, 4 University of California Davis
Coastal upwelling systems can serve as natural laboratories for assessing biological responses to future global ocean acidification projections. These systems, including the California Current Large Marine Ecosystem (CCLME), are characterized by seasonal shoaling of carbon-dioxide-rich waters that bathe nearshore communities in low-pH conditions. The goal of this study was to quantify the relative influence of pH among a suite of other monitored environmental factors on growth of the adult California musselMytilus californianus at 8 sites along the CCLME from central Oregon to southern California during the 2011 upwelling season. To assess the potential underlying influence of genetic or persistent phenotypic differences (e.g. age or prior exposure), mussels were transplanted to each site from both the local site population and a common population originating in Oregon. Our study reveals both local and regional-scale variations in mussel growth. These variations support the hypothesis that growth is reduced in alongshore low-pH regions and confirm the previously documented importance of temperature and primary productivity. Growth did not differ between local-site and common-site mussels, suggesting that prior exposure does not influence the effects of further exposure. We suggest that, despite a history of exposure to low-pH waters, mussel growth will be increasingly suppressed under forecasted ocean acidification.
Ruttenberg, B.I.1,3*, Bohnsack, J.A.1, Ault, J.S.2, Smith, S.G.2, McClellan, D.B.1, Javech, J.1, Serafy, J.1
DISTURBANCE AND RECOVERY OF REEF FISH COMMUNITIES IN THE FLORIDA KEYS: INSIGHTS FROM A 30 YEAR MONITORING PROGRAM
1 NOAA National Marine Fisheries Service, Miami, FL, 2 – Rosenstiel School for Marine and Atmospheric Sciences, University of Miami, Miami, FL, 3 – California Polytechnic State University San Luis Obispo
The diverse coral reef ecosystems of the Florida Keys have been dramatically altered by human activities. Historical data documented declines in fishery species that occurred 30-60 years ago, but these datasets lack spatial and temporal resolution. We use data from the Florida Keys long-term reef fish monitoring program, one of the longest continuous monitoring programs in marine systems, to examine changes in reef fish communities over the past 30+ years. While we found different trajectories for different species and functional groups, multivariate analyses show that reef fish communities have been changing in a consistent manner for 30 years. The timing of changes in single-species patterns suggests that multiple factors are driving community change. These include loss of live coral and species associated with coral habitats, and slight recovery of some heavily targeted fishery species, likely resulting from increased regulations and implementation of small MPAs in the Keys and larval export from large MPAs in the Dry Tortugas region, ~100 km upstream. Despite the increase in abundance of some fishery species, community metrics suggest that the Florida Keys is still a heavily exploited ecosystem that will require additional management and a long time frame to restore reef fish communities.
PUT YOUR TIPS OUT: HOW CORALLINES MAY DOMINATE SHALLOW NEARSHORE ENVIRONMENTS
Moss Landing Marine Laboratories
Coralline algae are ubiquitous in nearshore marine environments. In particular, geniculate corallines occur in intertidal and subtidal habitats with abundances typically higher in the shallows. Observations along the Monterey Peninsula have shown that abundances and morphology differ with depth. To further understand this pattern, this study was conducted to examine the effect of depth on morphology and physiology in the geniculate coralline, Calliarthron tuberculosum. Populations from 3 and 10 m depths were sampled at two sites to examine morphometric variables including total length, total width, and number of branch tips. Steady-state incubations and pigment profiles were conducted to compare physiological differences between the two populations. Preliminary results from incubations suggest that physiological parameters follow expected patterns with depth. Interestingly, the number of branch tips found on shallow individuals was double that of the individuals found at the deeper site while there are no apparent differences in total length and total width with depth. The density of branch tips may facilitate coralline dominance at shallower depths and have implications on the ecology of these nearshore environments.
OBSERVATION AND ECOLOGY: BROADENING THE SCOPE OF SCIENCE TO UNDERSTAND A COMPLEX WORLD
Institute of the Environment, University of Arizona
Ecology has entered into a dynamic period, characterized by a renewed reliance upon observational methods where the units of study are not manipulated in planned experiments. This shift has been driven by threats to life on Earth which occur across many scales, making them difficult to study with pre-determined hypotheses in isolated manipulations. Given this challenge, natural history, traditional and local ecological knowledge, and advanced observational technologies (e.g., remote sensing, animal borne sensors, genetics) are playing a growing role in ecology. Observation-based ecology increasingly relies on data collected outside of academic settings such as citizen science programs, and is far more integrated with the social sciences than ever before. The resulting mosaic of interrelated observations can provide unprecedented ecological understanding, but because these methods often rely on correlation, inductive inference, and narrative ways of knowing, they challenge us to question fundamental dogma about scientific method and inference.
Sanchez, A.S.*, Virtue, S.V., Hovel, K.A.
CAN SEAGRASS EPIPHYTES ALTER MESOGRAZER VULNERABILITY TO PREDATORS?
San Diego State University Coastal and Marine Institute Laboratory
In seagrasses, top-down control of crustacean mesograzers is receiving increasing attention because mesograzers consume epiphytes that grow on seagrass, potentially regulating seagrass growth. Though epiphytes provide food for mesograzers, they also add structural complexity and therefore may influence mesograzer vulnerability to predators. We conducted laboratory and field experiments to determine (i) whether epiphytic algae affects predator (fish) foraging efficiency and behavior when feeding on a common seagrass mesograzer (grass shrimp), and (ii) whether mesograzer abundance in the field is enhanced by the presence of epiphytes via habitat preference or reduced mortality. In laboratory mesocosms, the presence of epiphytes had an equivalent effect as increasing seagrass shoot density on reducing fish hunting activity and prey detection efficiency. However, after detecting prey, fish were more successful at capturing prey as structural complexity increased, possibly due to fewer escape attempts by grass shrimp, resulting in similar rates of prey capture across treatments. In the field, grass shrimp preferred seagrass plots with simulated epiphytes over seagrass plots with equivalent and higher shoot densities, but epiphytes did not reduce grass shrimp vulnerability to predators. We conclude that epiphytes affect prey and predator behavior, but do not reduce the vulnerability of grass shrimp mesograzers to predators.
Saunders, M.I.1, Foley, M.M.2*, Febria, C.M.3, Albright, R.4, Mehling, M.5, Burfeind, D.6, Kavanaugh, M.T.7, Brown, C.J.2
HUMAN INFLUENCES ON CONNECTIVITY NETWORKS IN MARINE AND FRESHWATER ECOSYSTEMS
1 Global Change Institute, University of Queensland, 2 Center for Ocean Solutions, Stanford University, 3 University of Maryland, 4 Australian Institute of Marine Science, 5 Chatham University, 6 Australian Rivers Institute, Griffith University, 7 Oregon State University
Connectivity has emerged as a critical driver of ecosystem structure and functioning in aquatic systems, influencing a range of ecological processes including population persistence, recovery, and maintenance of biodiversity. However, human activities are rapidly altering the structural, hydrologic, and functional processes that link organisms within and across habitats and populations, which are likely to affect the robustness, resilience, and persistence of ecological networks. We applied concepts from graph theory to examine how four major human stressorshabitat alteration, invasive species, overfishing, and climate changeinfluence properties of spatial ecological networks in marine and freshwater ecosystems. Using nodes (habitats/populations) and links (dispersal/migration) from the graph theory framework, we identified three generalities. First, habitat loss, overfishing and invasive species tend to act directly on nodes by removing individuals, populations, or habitats with secondary effects on links through diminished capacity for dispersal. Second, human movements and habitat addition contribute new links and nodes, which can increase the size and clustering of the network. Third, climate change affects both nodes and links in multiple and complex ways. Using this generalized framework to predict changes in connectivity as a result of human activities can guide management plans by helping to prioritize actions given limited resources.
Schiel, D. R.1, Zeldis, J.2, Barr, N.2
Cataclysmic earthquake-driven changes to an estuary in southern New Zealand
1 Canterbury University, Christchurch, New Zealand, 2 National Institute of Water & Atmospheric Research, New Zealand
Beginning on 4 September 2010, a series of earthquakes of magnitudes up to 7.1 struck the Canterbury region of southern New Zealand over several months. The central area of the city of Christchurch was largely destroyed and massive upheaval and liquefaction occurred throughout the area. The floor of the highly eutrophic Avon-Heathcote estuary was tilted by up to 1m, up to 60% of the benthic surface was covered by liquefaction, and large amounts of raw effluent flowed into the estuary from damaged wastewater pipes. The estuarine ecosystem was dramatically changed with different micro- and macro-algal dynamics, sediment structure and food web dynamics. Furthermore, there had been a diversion of Christchurchs treated wastewater from the estuary to an ocean outfall in early 2010 to reduce anthropogenic nutrient input, and so earthquake-driven effects were overlaid on this remediation. The ongoing effects and changes to estuarine dynamics over the past year are discussed.
Schmidt, K.T.*, Starr, R.M., Hamilton, S.L., Cailliet, G. M.
LIFE HISTORY CHANGES IN BLUE ROCKFISH, SEBASTES MYSTINUS SPP., AFTER HEAVY FISHING
Moss Landing Marine Laboratories
Changes in life history traits have been observed in some wild fish stocks following fisheries removals, especially in growth rate, fecundity, and size and age at maturation. Studies of biological characteristics of Blue Rockfish, Sebastes mystinus, occurred off central CA in the 1960s and 1980s, prior to the onset of heavy fishing. I collected Blue Rockfish from 2010 2012 to establish current estimates of fecundity, growth, and length and age at maturity, and compared these to the earlier studies. Also, differences between the life histories of the two Blue Rockfish species will be illustrated. The importance of the maturity changes of Blue Rockfish in regard to stock resilience and management policies, and the differences in the life histories of the two species, will be discussed.
Schoenrock, K.M.1, Amsler, C.D. 1, McClintock, J.B. 1, Baker, B.J.2
AN INVESTIGATION OF ENDOPHYTE EFFECTS ON MACROPHYTE HOST PHYSIOLOGY ALONG THE WESTERN ANTARCTIC PENINSULA
1 – University of Alabama at Birmingham, 2 – University of South Florida
Filamentous endophytic algae are commonly found within macrophyte hosts along the western Antarctic Peninsula. The impact of endophytes on their macrophyte hosts has been shown to vary between species. Previously, filamentous endophytes were shown to negatively impact host growth rates in two species of Antarctic algae. This study investigates the impact of endophytic algae on three aspects of host physiology: photosynthetic capacity, palatability and thallus toughness. These parameters were measured in a variety of common Antarctic macrophytes from the Austral winter of 2010 through 2012. Host species varied in their response to infection; however most were not negatively impacted by endophyte presence. The benign presence of these endophytic algae and host tolerance of a photosynthetic endosymbiont are indicative of a commensalism in many Antarctic species.
Schultz, J.A.*, Anderson, K. M., Harley, C. D. G., McCoy, S.
NUTRITION AND OCEAN ACIDIFICATION IN THE BLACK TURBAN SNAIL, CHLOROSTOMA (TEGULA) FUNEBRALIS (ADAMS)
Department of Zoology, University of British Columbia
Extreme variation in both pH and food availability is common in intertidal areas, and global climate change may exacerbate this variation. While many previous studies have addressed the impact of ocean acidification on intertidal organisms, few have considered how food availability may alter these impacts. In this study, we investigated the effects of nutritional status on acidification tolerance in the black turban snail, Chlorostoma funebralis. Snails were subjected to one of two feeding regimes: fed or not fed, and either control or elevated CO2 seawater. After three months, we measured the changes in both shell mass and activity levels. Snails grew faster when fed than when starved, and at ambient pH relative to reduced pH. Activity levels were higher in fed snails than in starved snails, but the effect of CO2treatment on activity level was non-significant. Our lab-based demonstration of reduced Chlorostomagrowth in acidified water corroborates field-based measurements of reduced growth in this species during a period of falling nearshore pH. These results provide some insight into the role energy budgets in calcification mechanisms, and help unravel some of the complexity of ecosystem interactions in response to climate change.
Selden, R.L.*, Gaines, S.D., Warner, R.R.
THE CONSEQUENCES OF FISHING-INDUCED CHANGES IN SIZE ON PREDATOR-PREY INTERACTIONS
University of California, Santa Barbara
Even without selecting for large fish, the added mortality of fishing means fewer fish make it to larger sizes, leading to distributions shifted towards smaller individuals. The consequences of these shifts for single-species management have long been recognized. Because body size limits the sizes of prey a predator can eat, truncated size distributions may cause equally dramatic changes in predator-prey interactions. As a result, multispecies models based on biomass alone, without considering changes in size distributions, may over- or under-estimate predation rates. The potential trophic effects have largely been ignored when managing these fisheries, but will be critical to fulfilling the mandate for multispecies management. I developed a size-structured predator-prey model to evaluate how fisheries-induced changes in predator size distributions affect prey population dynamics. I parameterized this model within California kelp forests using observations of size-specific predation of California sheephead (Semicossyphus pulcher) on urchins (Stronglyocentrotus spp.). When predation success varied with predator size, and predators were size-selective, shifts in size distributions toward smaller predator sizes decreased overall prey mortality rates, with disproportionate reductions for larger prey, and increased prey densities. These patterns suggest changes in predator size structure will lead to previously unexpected changes in prey size structure and abundance.
Shanks, A.L.1, Morgan, S.G.2, Macmahan, J.3, Reniers, A.J.H.M.4, Jarvis, M.1, Brown, J.3, Fujimura, A.4, Griesemer, C.2
SURF ZONE HYDRODYNAMICS AND THE DELIVERY OF LARVAE TO THE SHORE
1-Oregon Institute of Marine Biology, 2-Bodega Marine Laboratory, 3-Naval Postgraduate School, 4-Rosenstiel School of Marine and Atmospheric Science
Larvae of intertidal organisms developing in coastal waters must return to shore to complete their life cycle; they must migrate across the surf zone. Depending on hydrodynamics, the surf zone may be a barrier to shoreward migration. Surf zones associated with rocky shores are reflective and, while the surf zone is narrow, because they lack rip currents, water is less readily exchanged and the surf zone may act as a barrier to larval transport. At a sampled reflective shore, the surf zone acts like a leaky pipe (flow along the pipe = the alongshore current); the pipe was leakier during larger waves and longer period seas, but it was less leaky during longer period swells. The effect of waves on surf zone exchange was apparent in the concentration of phytoplankton in the surf zone. Competent larvae in the surf zone were significantly correlated with the concentration of detritus and competent larvae and detritus were more abundant during periods of smaller waves suggesting that larvae enter the surf zone during these periods and that migration into the surf zone is somehow analogous to the movement of detritus. Surf zone hydrodynamics does effect the ability of larvae to migrate to shore.
Shen, C.1*, Nielsen, K.J.2, Chan, F.1, Hacker, S.D.1, B.A. Menge, B.A.1
INVERTEBRATE DIVERSITY IN INTERTIDAL TURF ALGAE
1 Oregon State University, 2 Sonoma State University
Articulated coralline algae are characteristic habitat-formers in intertidal environments, fostering diverse invertebrate communities. Due to their high demand for calcium carbonate, their role in the ecosystem is vulnerable to climate-related changes in oceanic carbon chemistry. A reduction in the competitive ability of corallines suggests floristic shifts favoring non-calcified, or fleshy, algae. If fleshy algae become more dominant, what will be the implications for invertebrate diversity? In this study, coralline and fleshy turf samples were collected in summer 2012 at four sites ranging across 600 km along the Oregon-California coast. Invertebrate diversity was found to be higher in fleshy algae than in coralline algae, but taxon richness did not differ between the two. These results suggest that higher diversity in fleshy algae is explained by greater taxon evenness. While a shift from coralline algae to fleshy algae is not expected to reduce the diversity of turf-dwelling invertebrates, species composition and relative abundances may be altered.
Shippey, A.C., Whitcraft, C. R.
EFFECTS OF ALTERED PRECIPITATION AND INCREASED TEMPERATURE ON A RESTORED SOUTHERN CALIFORNIA SALT MARSH
California State University Long Beach
Salt marshes provide many critical ecosystem functions; several of which are threatened by human activities such as urban development and climate change. Restoration is one strategy utilized to deal with these threats. Under current climate conditions, restorations are known to be effective; yet, the success of these restorations is unknown under altered climate regimes. Southern California has a Mediterranean climate characterized by rain in the winter and dry conditions in the summer. Climate change projections for this region include increased frequency of severe storms, longer periods of drought, and increases in temperature. To understand these effects I am evaluating how altered precipitation and increased temperature will affect a restored high marsh berm in southern California. Structures made of PVC pipe and greenhouse plastic mimic these environmental changes and have been placed along the berm in a randomized block design. Continuous data loggers placed within each experimental plot indicate treatments are effective. There has been an overall decrease in plant cover for the increased temperature/decreased precipitation treatment. Microalgae abundance has increased in decreased precipitation treatment due to greater access to sunlight. Our results can assist managers with restoration planning under different climate change scenarios.
Simmonds, S.E.1*, Rachmawati, R.1, Cheng, S.1, Calumpong, N.2, Mahardika, N.3, Barber, P.H.1
Host-specificity and ecological speciation in corallivorous gastropods
1-University of California, Los Angeles; 2-Silliman University; 3-Udayana University
While studies of ecological speciation in the ocean are still in their infancy, there are several reasons to believe that this process may occur in the sea. Absolute dispersal barriers are exceedingly rare therefore speciation may proceed with varying levels of gene flow and this process is aided by divergent selection. Strong interspecific interactions (e.g., host-parasite) believed to promote ecological speciation in terrestrial species are ubiquitous in the marine realm. Our research seeks to reevaluate the importance of allopatric speciation in generating marine biodiversity by examining the speciation process in a group of corallivorous gastropods (Coralliophila neritoidea, Drupella spp.) found throughout the tropical Indo-Pacific. Reproductive isolation via host preference in coral-eating snails could promote population divergence, even in sympatry. By examining the population genetic and phylogeographic patterns across known breaks in the Coral Triangle and among sympatric populations of snails inhabiting different species of host coral, we compare the roles of geography and host specificity as isolating mechanisms in driving divergence.
Simonsen, C.M.*, Brito, M., Sandin, S.A.
CONTEXT SPECIFIC BITE RATE OF HERBIVOROUS FISH CORRELATE TO BENTHIC COMPOSITION
Scripps Institution of Oceanography, University of California, San Diego
The removal of algae by herbivorous fish has significant impact on coral reef dynamics and functioning. Specifically scarids (parrotfish) and acanthurids (surgeonfish) have the ability to remove a significant amount of turf and erect algae from a coral reef. However, in the past decade there has been a change in reef states from coral to algae in numerous Caribbean regions, suggesting an increase in algal growth rate or decrease in herbivory, or most likely both. We know that different species of herbivores have distinct food preferences and varying removal rates, however it is unclear if these removal rates are context-specific. By observing fish foraging behavior, we investigated the variability of fish foraging behaviors, specifically testing for links between fish rate and local benthic composition. By using observational methods and community assays, we found that herbivores have dynamic and context-specific foraging behavior across the island of Curacao. Fish had a bite rate twice as high on reefs with higher coral cover than sites with low coral cover. Further, the target of herbivory shifted, with fishes favoring the more abundant algal taxa across sites. Further observations and analysis will help us to understand how ecosystem diversity and distribution affect species behavior, and how herbivorous fish help maintain a healthy reef.
Siple, M.C.1,2 *, Donahue, M.J.1
RECOVERY OF BENTHIC COMMUNITIES FOLLOWING MANGROVE REMOVAL
1Hawaii Institute of Marine Biology, 2University of Washington
Red mangrove (Rhizophora mangle) was introduced to Hawaii in 1902 and has since overgrown many coastal areas in Hawaii, transforming nearshore sandy habitat into heavily vegetated areas with low water velocity, high sedimentation rates, and anoxic sediments. Mangrove forests provide habitat for exotic species, including burrowing predators, which can exert top-down effects on benthic communities. Removal of mangrove overstory is a popular management technique; here we use infauna community structure, crab catch data, and a cage experiment performed over a chronosequence of removals from 2007-2010 to show that overstory removal causes gradual changes in community composition, that community shifts are concurrent with a slow decomposition of sedimentary mangrove biomass (k = 5.6 10-4 0.9 10-4 d-1), and that burrowing predators do not exert significant effects on the infaunal community where R. mangle is intact or where it has been removed. Changes over time after removal include an increase in total infaunal abundance, as well as trophic guilds that are more abundant in uninvaded areas. Burrowing crabs do not affect infaunal communities as they do in native mangroves. These results show that recovery from invasion and removal occurs gradually and is not governed by top-down effects.
Sogin, E.M.1*, Putnam, H.M.1, Anderson, P.2, Gates, R.D.1
Is exposure to Global climate change stressors reflected in metabolite profiles of the coral Pocillopora damicornis?
1 – Hawaii Institute of Marine Biology, 2 – College of Charleston
Global climate change (GCC) is threatening coral reef ecosystems by increasing ocean acidification and sea-surface temperatures. These stressors can manifest in declines in coral calcification and increased coral bleaching and mortality. We examined coral physiology and metabolite profiles in corals exposed to a combination of these stressors. Replicate nubbins of Pocillopora damicornis were exposed to ambient (417 atm; 26.5C) and high (805 atm; 28.9C) levels of temperature and pCO2 for 1.5 months. High treatments negatively affected coral physiology. Specifically, photochemical efficiency of PSII, photosynthetic rates and the ratio of photosynthesis to respiration declined in high versus ambient treated corals, suggesting the high treatments caused photo-inhibition and reduced metabolic scope. Proton-Nuclear Magnetic Resonance metabolite profiles were obtained for the same coral nubbins. Metabolite profiles were binned and analyzed using multivariate statistics to compare treatments. Our results show a clear difference in metabolite profiles with increased GCC stress, with high variability in coral profiles from high conditions, and tighter groupings in ambient conditions. The increased variability in the metabolite profiles suggests that the high treatments influences and potentially reduces regulatory capacities in corals. The identification of specific metabolites responsible for these patterns will clarify key processes involved in coral response to GCC.
Sosik E.A.*, Simenstad C.A.
MICROBIAL TROPHIC LEVELS: EVIDENCE AND CONSEQUENCES IN ISOTOPE-BASED COASTAL ECOLOGY
University of Washington, School of Aquatic and Fishery Science
An expanding body of research suggests that subsidies of detritus from allochthonous sources are a critical carbon source in certain food webs, especially in interconnected ecosystems such as coastal zones. However, the role of microbial decomposition in detritus-based food webs has been poorly quantified and frequently overlooked, most especially among studies that rely heavily on tools such as multiple stable isotope (MSI) mixing models. The isotopic effect of microbial colonization on detritus is commonly assumed to be insignificant; however, in earlier experiments I determined that microbial decomposition may significantly shift the isotopic content of macroalgae detritus. In this analysis, I expand on that evidence to examine the methodological consequences of excluding microbial factors from MSI mixing models. I applied a microbial shift to the diet of a theoretical consumer, and used a Bayesian mixing model to test the outcome of scenarios which simulated different food-source sampling methods. To verify that the isotopic shifts associated with microbial decomposition can affect higher trophic levels, I also conducted a feeding experiment. The results suggest that microbial biofilms may significantly affect the isotopic composition of organisms that ingest it, and can introduce a significant amount of error to MSI mixing models if left unquantified.
THE COEVOLUTIONARY ARMS RACE BETWEEN SEAWEED DEFENSES AND HERBIVORE OFFENSES ON TROPICAL REEFS
College of Charleston
In tropical habitats, sea urchins and fishes are the principal consumers of seaweeds, and many of these seaweeds produce chemical defenses that minimize the impact of consumers. While it is possible that seaweed chemical defenses and herbivore feeding responses coevolve, there remains little evidence. Our laboratory tested two predictions that emerge from a coevolutionary arms-race. First, I review seaweed natural products and found that tropical genera are twice as likely as temperate genera to produce terpenes, the structural class of lipophilic secondary metabolites that is most commonly cited as a feeding deterrent in seaweeds. Second, I used 126 feeding preference assays to test whether tropical sea urchins have greater feeding resistance to lipophilic extracts from tropical seaweeds than do temperate urchins. Tropical Diadema and Echinometra species more readily consumed extract-laden foods than did temperate Strongylocentrotus species. In addition, populations of the urchin Arbacia punctulata from tropical reefs consumed significantly more extract from two Dictyota species and a Stypopodium species than did the temperate population. Our data are consistent with a diffuse coevolutionary arms race between herbivores and seaweeds within tropical habitats, and reinforce the roles that phylogenetic lineage and geographic origin have in the feeding responses of generalist herbivores.
Stachowicz, J.J.1, Kamel, S.J.2, Hughes, A.R.3, Grosberg, R.K.1
GENETIC RELATEDNESS VS. FUNCTIONAL DIVERSITY AS PREDICTORS OF BIOMASS ACCUMULATION IN EELGRASS (ZOSTERA MARINA)
1-University of California, Davis; 2-Princeton University; 3-Florida State University
In multispecies assemblages, phylogenetic relatedness predicts total community biomass. In assemblages dominated by a single species, increasing the number of genotypes increases total production, but the role of genetic relatedness is unknown. We used data from three published experiments and a field survey of eelgrass (Zostera marina), a habitat-forming marine angiosperm, to examine the strength and direction of the relationship between genetic relatedness and plant biomass. The genetic relatedness of an assemblage was a strong predictor of its biomass, more so than the number of genotypes. But contrary to the pattern in multispecies assemblages, greatest biomass was achieved in assemblages of more closely related individuals. The mechanisms underlying this pattern are still unclear, but our data support a role for trait differentiation and cooperation among kin. Many habitat forming species interact intensely with conspecifics of varying relatedness, thus genetic relatedness could influence the functioning of ecosystems dominated by such species.
Stanfield, E.R.*, Sreenivasan, A., Los Huertos, M.
ENVIRONMENTAL FACTORS ASSOCIATED WITH TOXIC CYANOBACTERIA IN PINTO LAKE, A COASTAL LAKE IN THE MONTEREY BAY AREA
California State University Monterey Bay
Cyanobacterial harmful algal blooms (CHABs) dominate and disrupt aquatic ecosystems by virtue of their rapidly expanding biomass and the production of potent toxins. Since 2007, CHABs and the cyanotoxin microcystin have been documented in freshwater bodies draining into the Monterey Bay National Marine Sanctuary (MBNMS) on the California Central Coast. In this study, we combined freshwater ecology and molecular biology approaches to characterize the abundance of potentially toxic cyanobacteria, intracellular microcystin levels, and presence of microcystin synthesis genes in association with environmental factors in Pinto Lake, a natural freshwater body seasonally draining into the MBNMS. We observed cyanobacteria abundance and microcystin levels increasing in 2009 through 2011 in association with temperature, water column stratification, organic carbon and decreasing dissolved nitrate. The presence of the microcystin synthesis gene mcyB correlated with potentially toxic cyanobacteria abundance and increasing intracellular microcystins. This research will contribute to more effective management strategy for reduction, remediation and prevention of toxic CHABs in shallow Mediterranean lakes, while providing baseline data on ecological dynamics and proliferation of toxic CHABs in the Monterey Bay region.
Sullivan, C.J.*, Zgliczynski, B.J., Price, N.N., Palaretti, C., Zerofski, P., Sandin, S.A.
SUB-LETHAL PREDATOR EFFECTS ON PREY GROWTH IN THE GENUS SEBASTES
Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography
The study of predator effects is typically focused on the finalistic aspect of such interactions. Although direct predation is undoubtedly important, there is a far less studied realm that is equally, if not, more important than the direct effects of predation. Here we examine the indirect growth effects of predator and prey interactions by using predator stimuli experimentation. Juvenile rockfishes of the genus Sebasteswere introduced to predation stimuli and within generation effects on growth were measured. Multiple experiments were run while manipulating visual and chemical stimuli. It was discovered that the existence of predation stimuli resulted in a consistent negative growth effect on both body length and height in juvenile rockfish. Although sub-lethal predator effects significantly stunted growth in both mean body length and height, weight was not affected. It has been seen that juvenile survivorship can differentiate based on size relationships, and therefore stunted growth of juvenile fish by predation presence may lead to changes in survivorship. This study also reinforces the theory that energy allocation and metabolism may play key role in the way that fish are affected by predation.
Taylor, A.W., Gravem, S.A., Morgan, S.G.
LIGHTS, CAMERA, ACTION! STUDYING THE EFFECTS OF WAVE ACTION ON INTERTIDAL SNAIL CHLOROSTOMA (TEGULA) FUNEBRALIS BEHAVIOR WITH UNDERWATER CAMERAS.
University of California, Davis. Bodega Marine Laboratory
Nearly all of our understanding of rocky intertidal ecology comes from studies conducted at low tide, but we have little understanding of processes occurring during high tide. We used a waterproof camera (GoPro) anchored in a wave-exposed intertidal environment to film the movements of the black turban snail Chlorostoma funebralis throughout the tidal cycle. ImageJ software was used to calculate average speed and vertical movement of snails. C. funebralis increased activity and moved in an upward direction for one hour surrounding the first wave of flood tide, which could suggest a chronobiological phenomena. Activity levels are low during high tide, probably to avoid dislodgment by waves. Snails may also be entering and leaving pools at high tide. No marked changes in activity occurred after the last wave of ebb tide; but snails tended to move downward, perhaps to avoid high temperature and salinity at the tidepool surface. Activity levels further decreased as low tide progressed, perhaps in response to physiological stress. This is one of the first projects to record activity of organisms in the wave-exposed intertidal at high tide, and the inexpensive methods used here are easily transferable for recording high tide activities of intertidal organisms.
Taylor, D.I. .1,*, McNabb, P. .1, Ogilvie, S.C. .1, Wood, S.A. .1,2, Cary, C.2
ALIEN INVASIONS, ZOMBIES, AND TOXIC SCAVANGERS: FACILITATION EFFECTS ON POPULATION EXPLOSIONS IN PLEUROBRANCHAEA MACULATA
1 – Cawthron Institute, 2 – University of Waikato
Facilitation of native species by invasive species often occurs through habitat modification, particularly when invasive species increase habitat complexity and provide a limiting resource. These processes were highlighted after a series of dog deaths on New Zealand beaches, where the deadly neurotoxin, tetrodotoxin (TTX), was identified as the causative agent. Populations of sea-slugs, Pleurobranchaea maculata, were found to contain high levels of TTX in the range of 5-2450 mg kg-1, with the toxin found in egg sacs, juveniles and adults. Diver surveys, at the beaches where dog deaths had occurred found P. maculata abundances reached 0.9 per m2 on beds of the invasive Asian Date (or Bag) mussel, Musculista senhousia. Large non-toxic populations of P. maculata have subsequently been found on offshore mussel farms (growing native Greenshell mussels, Perna canaliculus) in another part of the country. Results of field experiments and Q-PCR assays suggest that both invasive and indigenous mussel beds facilitate population explosions of P. maculata by providing novel egg-laying habitat, ideal settlement and recruitment substrata and an on-going food source for this scavenging species.
Teck, S.J.* 1, Cornejo-Donoso, J. 2, Rathbone, S. 2, Shears, N.T. 3, Hamilton, S.L. 4, Caselle, J.E. 2, Gaines, S. D. 1,2,5
CALIFORNIA’S GOLD: REPRODUCTIVE VARIABILITY OF RED SEA URCHINS, STRONGYLOCENTROTUS FRANCISCANUS, AT THE NORTHERN CHANNEL ISLANDS
1 – Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, 2 – Marine Science Institute, University of California, Santa Barbara, 3 – Department of Statistics, University of Auckland, 4 – Moss Landing Marine Laboratories, 5 – Bren School of Environmental Sciences, University of California, Santa Barbara,
For the roe-based red sea urchin (Strongylocentrotus franciscanus) fishery, the gonads of harvested individuals must be the proper size, texture, color and freshness in order to be profitable in the competitive international and domestic markets. For the past decade the red sea urchin fishery has been the fifth largest fishery in California, and all urchins are collected by hand. In order to properly manage this fishery for optimal profits and sustainability, researchers must examine not only temporal and spatial variability in sea urchin density and size frequency across the management area but also gonad quality. We find that gonad quality as reflected in sea urchin price per pound is highly correlated with gonadosomatic index (GSI; percent gonad of whole body weight). We find that GSI varies across the islands and peaks in winter months in accordance with the annual spawning cycle. In general red urchin biomass and reproductive output are higher inside reserves than outside of reserves and higher in the northwestern Channel Islands than the northeastern Channel Islands and mainland sites. Understanding reproductive patterns in red sea urchin populations can not only inform managers and fisheries biologists but also contribute to more detailed population dynamic and bioeconomic models.
Tenggardjaja, K.A.1*, Bowen, B.W.2, Bernardi, G.1
INVESTIGATING GENETIC CONNECTIVITY IN A HAWAIIAN DAMSELFISH FOUND ON SHALLOW AND MESOPHOTIC CORAL REEFS
1 University of California Santa Cruz, 2 Hawaii Institute of Marine Biology
Mesophotic coral ecosystems (MCEs) characterize the largely unexplored 30-150 m depth range of coral reef systems. Since MCEs are well-protected from storm damage and thermal stress, they have been hypothesized to act as: 1) a source to replenish populations on shallow reefs after a disturbance or 2) refugia, where shallow populations can weather out adverse conditions. Because MCEs are still a relatively new study system, there are few studies that have evaluated connectivity between shallow and mesophotic reefs, but mesophotic populations of corals have been found to be significantly differentiated from shallower populations. This study utilizes two mitochondrial markers to investigate vertical connectivity in Chromis verater, a Hawaiian endemic damselfish. Levels of genetic differentiation will be compared between specimens collected on shallow (< 30 m) and mesophotic (> 30 m) reefs at several sites throughout the Hawaiian Archipelago. Since macroalgal beds in MCEs have been implicated as potential nursery habitat for juvenile fish, data on the degree of connectivity in fish species found on both shallow and mesophotic reefs may yield significant conservation implications.
Tepolt, C.K.*, Somero, G.N.
INTRASPECIFIC VARIATION IN CARDIAC PHYSIOLOGY IN THE INVASIVE GREEN CRAB, CARCINUS MAENAS, IN NORTH AMERICA
Hopkins Marine Station
Invasive species are, by definition, able to survive and thrive in environments novel to them. This quality makes invasion biology an ideal framework in which to examine the physiological characteristics of species likely to succeed under a climate change regime. One particularly successful invader is the European green crab (Carcinus maenas), which has established non-native populations on five continents. In North America, the species has become established along broad environmental gradients on both the east and west coasts. We characterized high and low temperature tolerance and acclimatory plasticity at five sites spanning this North American range. We find that C. maenas maintains exceptional thermal tolerance while retaining significant acclimatory plasticity at many sites. We see little evidence for post-introduction adaptation, but do see indirect evidence for thermal differences between populations derived from different native range sources. Finally, we note that tolerance and plasticity remain high in the west coast relative to its east coast source, despite a loss of neutral genetic diversity in the west due to a founding bottleneck. Overall, C. maenas appears to succeed in the short term through its exceptional eurythermality, with potential adaptation to local conditions over longer time scales.
TinHan, T.C.1, Erisman, B.E.2, Aburto-Oropeza, O.2, Weaver, A.H.3, Hernndez, D.X.4, Vzquez Arce, D.I.3, Lowe, C.G. 1
LONG TERM HORIZONTAL AND VERTICAL MOVEMENTS OF YELLOW SNAPPER AND LEOPARD GROUPER AT THE LOS ISLOTES RESERVE, GULF OF CALIFORNIA
1 California State University Long Beach, 2 Scripps Institution of Oceanography, 3 Sociedad de Historia Natural Niparaja AC, 4 Universidad Autonoma de Baja California Sur
Gulf of California coastal fisheries heavily target species during seasonal spawning aggregations, and this is thought to negatively affect populations. Marine reserves have been proposed to mitigate losses resulting from this practice, but it is difficult to implement effective reserves without information about the movement patterns of populations. Between August 2010 and Sept 2012, we used acoustic telemetry to continuously monitor movements of 31 yellow snapper and 25 leopard grouper at the Los Islotes reserve, a small rocky reef and reported spawning site for both species in the southwest Gulf of California. Overall, both species exhibited site fidelity to Los Islotes (grouper: present 64 30 % of days; snapper: 49 30 %). Site fidelity did not differ significantly between spawning/non-spawning periods. Snapper used less of the available reserve area, exhibited greater site attachment to specific portions of the reserve, and occupied a shallower range of depths than grouper (snapper: 6.5 3.5 m; grouper: 9.3 4.1 m). For both species, horizontal and vertical rates of movement peaked during crepuscular periods. The overall patterns of residence to Los Islotes and lack of spawning-related emigration suggests these species may benefit from the year-round protection afforded by a permanent reserve.
Tissot, B. N.
SUSTAINABILITY IN THE MARINE AQUARIUM TRADE
Washington State University Vancouver
Sustainability is the challenge of our time. Because the global trade in marine ornamentals for aquaria is large and can result in severe impacts to coral reef ecosystems, sustainability in the trade is a challenging concept. However, twenty years of community-based management in Hawaii has resulted in a unique situation that has shown persistence and resilience during periods of ecological and social change that provide important insights into the key elements underlying sustainability. Using an integral perspective I redefine sustainability as it is traditionally used and examine Hawaii for the required elements of the new model. These elements require effective adaptive management has access to adequate levels of scientific data to understand dynamic changes in resources and a well-networked community that is engaged in co-management with a strong and supportive government.
Thompson, A.R.1, Adam, T.C.2, Hultgren, K.M.3*, Thacker, C.E.4
Ecology and evolutionary history affect network structure of a tropical shrimp-goby mutualism
1-National Marine Fisheries Service, 2-University of California Santa Barbara, 3- Seattle University, 4- Natural History Museum of Los Angeles County
Mutualistic interactions are ubiquitous across marine ecosystems, yet most research on mutualistic networks has been conducted in terrestrial systems. Recent meta-analyses suggest that in terrestrial mutualistic networks, species involved in more intimate, obligate mutualistic relationships tend to be more specialized than species in more facultative relationships. However, the degree of specialization and the factors that constrain partner interactions in marine mutualist networks are largely unknown. We present the first analysis of degree of specialization (H2) for marine mutualistic networks, using gobies and shrimps that are obligate associates on coral reefs. Mean specialization in these goby-shrimp networksacross eight Indo-Pacific regionswas statistically indistinguishable from comparably obligate terrestrial mutualisms, and significantly higher than more facultative terrestrial mutualisms. Specialization was affected by variability in habitat use for both gobies and shrimps; in addition, phylogenetic history influenced partner choice for shrimps (even after factoring out effects of habitat), but not for gobies. This asymmetry appears to result from evolutionary constraints on partner use by the shrimps, as well as convergence among distantly-related gobies to use burrows provided by multiple shrimp species. These results suggest that that similar processes influence the ecology and evolution of mutualisms in both terrestrial and marine environments.
Toews, S. 1, Garza, C.2
A GEOSPATIAL APPROACH TO MODELING HABITAT COMPLEXITY AND COMPOSITION ASSOCIATIONS IN THE NEARSHORE ROCKY SUBTIDAL
1 California Ocean Protection Council, 2 California State University Monterey Bay
The structural complexity of the seafloor plays an important role in the distribution of benthic communities. In California, the California State Mapping Project (CSMP) has provided a comprehensive dataset of high resolution seafloor bathymetry and derived products for its state waters. In this study we consider the role that habitat complexity (three dimensional structure of the seafloor) may play on habitat composition (abundance and distribution of benthic communities), in the nearshore along the Monterey Peninsula.
Habitat complexity was estimated using derived products from the seafloor mapping data while habitat composition was estimated from georeferenced photoquadrats, calculating percent cover of four habitat classes (red, articulated coralline, and laminarial algae, and biogenic cover). We used a spatially explicit model comparison approach to describe the linkage between the physical and biological variables. Habitat complexity measures were useful for describing both red and articulated coralline algal habitats but not for laminarial and biogenic habitats.
This study demonstrates that landscape based metrics of habitat complexity can provide descriptive and predictive estimates of habitat composition in nearshore ecosystems. There is great potential for managers to estimate habitat availability using physical qualities of nearshore areas using complexity measures from seafloor mapping data, available for the coastal waters of California.
Tompkins, P.T.1,2*, Wolff, M.1, Ruiz, D.J.1
ROLE OF MACROALGE IN THE MARINE TROPHIC WEB OF THE GALAPAGOS ARCHIPELAGO
1 – Leibniz Center for Tropical Marine Ecology, 2 Charles Darwin Foundation
The dynamic oceanographic setting of the Galapagos archipelago (confluences of cold and warm water masses) has allowed for the development of a uniquely diverse, abundant, and biogeographically segregated marine community. Given its protected status and multiple stakeholders, the trophic structure and function of the marine ecosystem are of particular importance. Relevant stakeholders of the Galapagos – Tourism, fishing, research, and conservation, hinge on the biodiversity and productivity of the waters around the islands, which are greatly influenced by oceanographic cycles (e.g. ENSO). Small-scale trophic models have been created for subsystems of the archipelago to describe food web structure and energy flow, and to model the importance of physical and biological drivers of observed ecological dynamics. With >300 species described, macroalgal communities are highly diverse, and are locally abundant. Detailed information on Galapagos macroalgal ecology is currently lacking. Since spatio-temporal changes in primary production greatly control energy flow and community structure, a closer look at the macroalgal clade of the archipelago is needed. This work seeks to address this knowledge gap in the context of understanding the importance of bottom-up control of the energy flow in the archipelago under conditions of anticipated future environmental changes, specifically ocean acidification and rising temperatures.
Tootell, J.S.*, Steele, M.A.
HOW STRUCTURE, AGONISM, AND VERMETID GASTROPODS AFFECT HERBIVORY ON A CORAL REEF, AND IMPLICATIONS FOR RESILIENCE
California State University Northridge
Herbivory is essential to the resilience and recovery of coral reef ecosystems. This study examined how foraging of herbivorous fishes around Moorea French, Polynesia may be altered by three processes: habitat structure, interference competition, and negative indirect effects of a vermetid gastropod (Dendropoma maximum). Foraging was assessed using timed observations of bite rates on algal-turf covered substrata. Foraging rate was compared among five microhabitat types in an observational study; and then differences among microhabitats were evaluated more rigorously with a turf transplant experiment that crossed microhabitat source of turf with microhabitat destination. Vermetid mucous nets were removed to test their effect on foraging. Foraging intensity (bites m-2 min-1) and biomass-adjusted foraging (bites*biomass m-2 min-1) differed among five microhabitats (high, mid, and low bommies, pavement, and rubble), suggesting that fishes preferred to graze in certain areas. Algal transplants corroborated preferential grazing, showing the same patterns despite altered origin of turf. Vermetid mucus nets deterred grazing. Removal of vermetid mucous increased foraging intensity by about 220%; but the magnitude of this effect varied among microhabitats. These interactions have the potential to alter grazing in shallow reef systems, resulting in increased algal proliferation, and potentially altering the resilience and recovery of these systems.
Turner, C.R. 1,2,3*,, Stillman, J.H. 2,3, Dorfman, R.E. 2,3, Page, T.M. 2,3
THERMAL SENSITIVITY OF HEAT SHOCK PROTEIN GENE EXPRESSION IN NEWLY SETTLED PORCELAIN CRABS
1 California State University Monterey Bay, 2- San Francisco State University, 3 Romberg-Tiburon Center
Intertidal zone organisms are adapted to thermal extremes, and upper vertical zonation limits are set by thermal tolerance limits. While much is known of thermal tolerance in adults, there are fewer studies that have examined the impact of heat waves on juveniles. In order to examine the impact of heat waves among newly settled juvenile porcelain crabs, we determined the induction temperatures for heat shock protein (hsp) gene expression in two porcelain crab species: the less heat tolerant low intertidalPetrolisthes manimaculus and the more heat tolerant mid-upper intertidal Petrolisthes cinctipes. We hypothesized that hsp gene expression will begin at lower temperatures for P. manimaculus than for P. cinctipes. To assess organismal response to heat stress, we performed qPCR using housekeeping gene -Tubulin and target genes hsp40 and hsp90. Hsp40 induction occurred between 23-25.5C in both P. manimaculus and P. cinctipes. In contrast, hsp90 induction was between 21- 23C in P. manimaculus, but >25.5C in P. cinctipes. Our initial analyses suggest that interspecific differences in thermal stress tolerance may be in part due to differences in induction temperatures of hsp90 between species. However, further work is needed to quantify ontogenetic shifts in the hsp90 induction temperature in each species.
Tuttle, L.J.*, M.A. Hixon
DO INVASIVE RED LIONFISH (PTEROIS VOLITANS) ALTER CLEANING MUTUALISMS ON BAHAMIAN CORAL REEFS?
Department of Zoology, Oregon State University
The red lionfish is an invasive species in the tropical western Atlantic that could greatly alter cleaning mutualisms, resulting in unforeseen indirect effects on coral-reef communities. I conducted an experiment on Bahamian reefs in which I observed cleaning stations after placing in random sequence clear-plastic bottles next to the station: one with a lionfish inside, one with an ecologically similar native predator (graysby grouper, Cephalopholis cruentata), and one as an empty bottle control. After nearly 50 hours of observation at 6 different cleaning stations, there was little evidence that the mere presence of a lionfish altered cleaning interactions when compared to other treatments. Cleaner fish near a lionfish spent 8.2% of their time cleaning at a rate of 6.8 cleaning events per hour, compared to 5.4% and 6.0 events/hour near a graysby, and 5.3% and 7.1 events/hour near an empty bottle. While the bottled graysby was approached many times by both cleaners and conspecifics, neither the lionfish nor the empty bottle were ever inspected by other fishes. The failure of cleaners and their clients to change their behavior in the presence of lionfish may confer some advantage to this invader hunting at cleaning stations.
Valentino, L.M. Carpenter, R.C.
EFFECTS OF OCEAN ACIDIFICATION ON BIOEROSION OF BURROWING BIVALVES IN MOOREA, FRENCH POLYNESIA
California State University, Northridge
Anthropogenic pCO2 causing ocean acidification (OA) is projected to decrease ocean surface pH by 0.140.35 units by the year 2100. Bioerosion of coral reef ecosystems is predicted to accelerate due to this unprecedented rate of decline in ocean pH. I tested the effects of ocean acidification on the boring capacity of Lithophaga laevigata living within living massive Porites. L. laevigata, a boring bivalve, is abundant within massive Porites on the back reef of Moorea. Data collected for Lithophaga abundance in massive Porites across the backreef ranged in abundance from 3 to 95 ind/m2. Size analysis of Lithophagashowed correlation of the borehole opening and valve size, which allows external quantification ofLithophaga growth. I conducted a month-long mesocosm experiment where coral cores with and withoutLithophaga, were incubated in ambient and elevated pCO2 treatments held at a constant temperature. I compared the bioerosion rate of Lithophaga in coral cores (based on changes in buoyant weight), and tested the hypothesis that the efficiency of Lithophaga bioerosion will increase in elevated pCO2conditions. A better understanding of this abundant and active bioeroder under simulated future environmental conditions can provide insight to the poorly understood effects of OA on bioerosion.
Wall, C.B.*, Edmunds, P.J.
IN SITU EFFECTS OF LOW-pH AND ELEVATED-DIC ON THE CALCIFICATION AND RESPIRATON OF JUVENILE MASSIVE PORITES SPP.
California State University Northridge
Increased atmospheric pCO2 leading to ocean acidification (OA) is predicted to negatively affect reef corals by reducing calcification rates and is hypothesized to affect rates of respiration and metabolism. In this study, juvenile massive Porites spp. were exposed to three seawater treatments of manipulated pH and [DIC] (pH8.04, DIC2.0mM; pH7.73, DIC2.2mM; pH7.69, DIC3.0mM) within sealed chambers that were maintained in situ under ecologically relevant exposures of temperatures, irradiance, and water motion. We tested the hypothesis that OA conditions (e.g., low-pH, low-arag, high-pCO2) reduce coral respiration and calcification rates and increases the metabolic expenditure concurrent with calcification (e.g., cost of calcification). Alternatively, very-high [DIC] (~3.0mM) was hypothesized to stimulate coral calcification under OA conditions by increasing the availability of carbon for calcification. Results showed calcification was affected by treatments, with coral calcification at pH7.69 DIC3.0mM increasing 58% relative to controls (pH8.04, DIC2.0mM); respiration and the energy expenditure concurrent with calcification were not affected. These findings indicate Porites spp. is resistant to short-term OA exposure under in situconditions, and that increased [DIC] (3.0mM) can increase calcification at low-pH and low-arag. Poritesspp. may therefore be DIC-limited an ambient DIC conditions (2.0mM).
The failed introduction of Sagartia elegans in Salem Harbor, MA
University of New Hampshire
Introduced species are becoming increasingly recognized as a serious problem as invasions are becoming more common and have been well documented to alter population, community, and ecosystem structure and function. Many studies have reported the arrival and subsequent range expansion of foreign species within the marine ecosystems, but few studies have documented a species that arrives and fails to establish. In 2000, the sea anemone Sagartia elegans was first found in Salem, MA on a rapid-assessment survey. The population rises seasonally in late summer and by early winter disappears. It persisted in Salem Harbor until the winter of 2010-2011 after which it has not been found. In both laboratory and field based temperature growth studies, S. elegans began regressing around 11C, stopped asexually reproducing at 9C, and died by 4C; these temperatures are far above the average winter sea surface temperature in the Gulf of Maine. Abiotic factors such as temperature or salinity are most likely the main cause of the collapse of the population.
Wells, E.H.* Grosholz, E.D.
FLIGHT, BURIAL, ARMOR: TWO INVASIVE SNAILS EXHIBIT DIFFERENT ANTIPREDATOR RESPONSES TO THE EUROPEAN GREEN CRAB CARCINUS MAENAS
University of California Davis
Non-native species in a new community may have predatory interactions that were not shaped by a shared evolutionary history. We studied antipredator responses of two introduced gastropods, the Western Atlantic mud snail Ilyanassa obsoleta and the Asian horn snail Batillaria attramentaria, to predation by the introduced European green crab Carcinus maenas. Using behavioral experiments that compared the flight, burrowing, and shell-thickening responses of the two snails in response to a variety of olfactory predation cues, we found that the two snails respond differently to crab predation cues. While Batillariaresponded to crushed conspecifics with increased burrowing, its shell thickened less in the presence ofCarcinus and it crawled least in response to crushed conspecifics, which may both be maladaptive responses to crab predation. Ilyanassa showed no flight or burrowing response to any crab or prey cues, and its shell-thickening responses to various prey cues were either inappropriate or beneficial through an indirect mechanism. Carcinus maenas has the potential for more density-mediated and trait-mediated effect on Batillaria than on Ilyanassa. These results emphasize that interactions between evolutionarily novel species can be difficult to predict, but are important in understanding the total impact of an invasive species and future community structure.
White, C.1*, Costello, C.1, Kendall, B.E.1, Brown, C.J.2
The value of coordinated management of interacting ecosystem Services
1 University of California, Santa Barbara, 2 – University of Queensland, St Lucia
Coordinating decisions and actions among interacting sectors is a critical component of ecosystem-based management, but uncertainty about coordinated managements effects is compromising its perceived value and use. We constructed an analytical framework for explicitly calculating how coordination affects management decisions, ecosystem state and the provision of ecosystem services in relation to ecosystem dynamics and socioeconomic objectives. The central insight is that the appropriate comparison strategy to optimal coordinated management is optimal uncoordinated management, which can be identified at the game theoretic Nash equilibrium. Using this insight we can calculate coordinations effects in relation to uncoordinated management and other reference scenarios. To illustrate how this framework can help identify ecosystem and socioeconomic conditions under which coordination is most influential and valuable, we applied it to a heuristic case study and a simulation model for the California Current Marine Ecosystem. Results indicate that coordinated management can more than double an ecosystems societal value, especially when sectors can effectively manipulate resources that interact strongly. However, societal gains from coordination will need to be reconciled with observations that it also leads to strategic simplification of the ecological food web, and generates both positive and negative impacts on individual sectors and non-target species.
Willette, D.A.1,2*, Santos, M.D.2, Weber, M.3, Carpenter,K.E. 4
CENTRIFUGAL SPECIATION IN EPIPELAGIC SARDINES: RAPID EVOLUTIONARY DIFFERENTIATION DRIVEN BY LOCAL ADAPTATION AND CLIMATE CHANGE
1 University of California Los Angeles, 2 Philippines National Fisheries Research and Development Institute, 3 University of California Merced, 4 Old Dominion University
Allopatric speciation models are the basis for phylogeographic tests of hypotheses regarding the origin of the extreme biodiversity of the Coral Triangle. Centrifugal speciation, a special form of allopatric speciation, differentiates between an ancestral population and derived remnant populations which evolved in isolation after changing environmental conditions retracted the species range. Here we investigated the evolutionary origin of the worlds only freshwater sardinella, Sardinella tawilis. We combined molecular and morphological data with geologic and oceanographic history to evaluate the hypothesis that Sardinella hualiensis and S. tawilis evolved by centrifugal speciation. Molecular cladistics inferred five clades for the two species from three sampling sites with a minimum of ten mutational steps distinguished the groups. A strict molecular clock model placed the beginning of lineage divergence during the late Pleistocene, prior to published dates of separation of the freshwater environment from the marine habitat. Changing climate and oceanographic features likely influencing the isolation and divergence of the Sardinella lineages. These data challenge the assumption that species with broad geographic ranges and large effective population sizes require large periods of time or distance to become isolated, and provides original evidence that centrifugal speciation may contribute to the Coral Triangle regions extraordinary biodiversity.
Wolfe, B.W.*, Lowe, C.G.
BEHAVIORAL CLASSIFICATION AND ANALYSIS OF FISH MOVEMENTS: HOW WHITE CROAKER USE THE PALOS VERDES SHELF, CALIFORNIA
California State University Long Beach
The search for and exploitation of food resources, or foraging, is among the most important behaviors fish engage in. Studying foraging related movements can provide insight into the characterization of core feeding areas, patch switching dynamics and other decision making behaviors used by fishes. We used a VPS acoustic telemetry array to study the fine-scale movements of 97 white croaker (WC) in an eight km2 area on the Palos Verdes Shelf (PVS) from July 2010 April 2012. WC position data were rendered into regular time-step movement trajectories with a continuous-time correlated random-walk model. A Bayesian partitioning algorithm was used to classify individual WC movement trajectories into several pseudo-behavioral modes, including a potentially foraging-related area-restricted behavior (ARB) mode characterized by high turning angles, and a more directed, linear transit mode. The temporal and spatial distributions of these pseudo-behaviors were analyzed with regard to proportion of time potentially spent foraging, location of important foraging areas, and habitat-specific interactions of WC while engaged in different modes. When used in conjunction with sediment contamination data, this approach may elucidate which areas of the PV shelf potentially contribute to organochlorine uptake in WC.
Wrubel, K.R.1*, Tissot, B.N.1, Bowlby, E.2, Brenkman, K.2, and J. Bright2
FISH-HABITAT ASSOCIATIONS WITHIN THE OLYMPIC COAST NATIONAL MARINE SANCTUARY
1- Washington State University Vancouver, 2- Olympic Coast National Marine Sanctuary
Populations and sizes of many commercially important groundfish species have been declining for decades along the west coast. This fishery stock decline, in association with the reauthorization of the Magnuson-Stevens Fishery Conservation and Management Act of 2006 resulted in the need to identify and protect essential fish habitat (EFH) for all commercially targeted fish species. To define a species EFH, an understanding of its utilization of habitat is required. Our project used remotely operated vehicles to conduct surveys in the Olympic Coast National Marine Sanctuary (OCNMS) to identify areas with deep-sea corals and sponges and quantify fishs interactions with these biogenic structures. Using video transects, fish were identified and their associations with the physical habitat and deep-sea corals and sponges were observed and quantified. Rockfish accounted for the majority of all fish observed (~70%). Boulder habitats had the highest density of fish, accounting for one-third of all rockfish species, even though boulders accounted for only 7% of available the habitat. This research will improve our understanding of how groundfish utilize physical and biogenic habitats within the OCNMS and help inform ongoing management efforts regarding the identification and conservation of EFH.
Aiken, E.A.*, Lonhart, S.I., Lindholm, J.B.
NATIVE CRAB, CANCER GRACILIS, MAY AFFECT THE SPREAD OF THE INVASIVE BRYOZOAN WATERSIPORA SUBTORQUATA
1 Institute for Applied Marine Ecology, California State University Monterey Bay, 2 Monterey Bay National Marine Sanctuary, NOAA
Invasive species continue to affect marine systems by altering community structure and function. The hull-fouling bryozoan Watersipora subtorquata was unintentionally introduced to the central coast of California in the 1990s and subsequently spread and monopolized several harbor ecosystems. While conducting a research diving project on the dispersal potential of Watersipora bryoliths in the Monterey Harbor, we observed native cancer crabs Cancer gracilis demolishing bryoliths used in our experiments. We then began a series of experiments to determine if the crabs were feeding on the bryolith itself or destroying the bryolith to gain access to the numerous invertebrates (e.g., shrimp, annelids, flatworms) that use the bryolith as habitat. Preliminary data indicate the crabs are focusing on the inhabitants rather than the bryozoan. Since bryoliths may contribute to the spread of Watersipora, destruction of bryoliths by crabs may serve as a natural impediment to dispersal and slow the rate of spread within the harbor.
Anderson, S.S. *, Kvitek, R., Walker, S., Boross, L., Craig, J., Geist, Z.1, Hansen, L., Jones, L., Lashly, E., McCandless, J., Migdli, M., OMalley, K., Posekian, K., Rodriguez, D., Vegos, P.
HIGH-RESOLUTION MAPPING OF SOUTHERN CALIFORNIA ESTUARIES FOR IMPROVED MANAGEMENT I: SANTA CLARA RIVER ESTUARY
1California State University Channel Islands, 2California State University Monterey Bay
High-resolution bathymetry is lacking for almost all of Californias coastal estuaries and lagoons. These ecosystems have historically been difficult do map owing to a combination of logistical and practical factors. In September of 2012, we used the new Kelp Fly (a highly modified 160hp Yamaha Waverunner equipped with GPS sub-meter mapping technology) to create the first high-resolution benthic map of the Santa Clara River Estuary (Ventura County, CA). The Santa Clara River Estuary is seasonally-closed with a complex hydrogeomorphology; the river is frequently dewatered for 14 river miles above the estuary by agricultural diversions and so the bulk of inflows during closed-mouth conditions come from direct effluent discharge via the City of Venturas Sewage Treatment Plant. Our new map will prove central to current discussions surrounding the contentious re-permitting of that treatment plant. We are using our new bathymetry to predict the effect of alternative discharge scenarios upon the estuary, articulate potential habitat for endangered steelhead (Oncorhynchus mykiss) and tidewater goby (Gobius newberryi), and explore potential longer-term changes in hydrogeomorphology.
Anderson, S.S.*, Kvitek, R., Walker, S., Boross, L., Craig, J., Geist, Z., Hansen, L., Jones, L., Lashly, E., McCandless, J., Migdli, M., OMalley, K., Posekian, K., Rodriguez, D., Vegos, P.
HIGH-RESOLUTION MAPPING OF SOUTHERN CALIFORNIA ESTUARIES FOR IMPROVED MANAGEMENT II: MUGU LAGOON
1 – California State University Channel Islands, 2- California State University Monterey Bay
High-resolution bathymetry is lacking for almost all of Californias coastal estuaries and lagoons. These ecosystems have historically been difficult do map owing to a combination of logistical and practical factors. In September of 2012, we used the new Kelp Fly (a highly modified 160hp Yamaha Waverunner equipped with GPS sub-meter mapping technology) to create the first high-resolution benthic map of Mugu Lagoon (Ventura County, CA). Mugu Lagoon is home to one of southern Californias largest remnant salt marshes at the base of Calleguas Creek. Calleguas Creek is a highly dynamic system cutting through highly friable soils. This watershed and lagoon have experienced a range of sediment management over time and as such has fostered a very poor understanding of the sedimentation dynamics within Mugu Lagoon. We are using these new benthic maps to begin to understand the depositional history of the estuary and assist with the designation of new sediment TMDLs for this watershed.
Aquilino, K.M.*, McGinn, N.A., Catton, C.A., Rogers-Bennett, L., Moore, J.D., and G.N. Cherr
WHITE ABALONE (HALIOTIS SORENSENI) CAPTIVE BREEDING PROGRAM
1 – Bodega Marine Laboratory, University of California, Davis, 2 – California Department of Fish and Game
Efforts at the Bodega Marine Laboratory and partner institutions have yielded the first successful captive production of juvenile white abalone (Haliotis sorenseni) in nearly a decade. As wild populations of this federally endangered species continue to decline, captive breeding and outplanting become more critical to its recovery. Water-borne pathogens and difficulties in conditioning broodstock have created challenges for captive breeding programs. Maintaining abalone health through treatment of infected animals as well as measures to prevent abalone exposure to pathogens and shell boring organisms has improved the health of captive broodstock at multiple facilities. Reliable reproductive conditioning of adults will increase the chance of successful future breeding efforts. We are manipulating light regimes and temperatures in broodstock holding tanks in order to increase our understanding of environmental parameters responsible for reproductive triggers, which is essential for improvement of captive breeding approaches for this critically endangered mollusk.
Beas-Luna, R1*., Black, A.2, Novak, M.1,3, Carr, M.1, Caselle, J.2, Estes, J.1,4, Levin, P. 5, Tinker, T.1,4
THE KELP FOREST ECOLOGICAL ONLINE DATABASE.
1- University of California, Santa Cruz (UCSC), 2- University of California Santa Barbara (UCSB), 3 – Oregon State University, 4 – USGS Western Ecological Research Center, 5 – Northwest Fisheries Science Center, NOAA Fisheries Service
Knowledge about spatial and temporally explicit life history traits of organisms that interact in a community is crucial for understanding the structure and function of natural ecosystems. Ecology is increasingly becoming a data intensive science, relying on amazing amounts of information collected from field and laboratory experiments as well as monitoring programs. Thus, identifying critical information to help answer ecological questions is becoming more and more challenging. Here, we review, integrate, and organize: Identities, life histories and interactions between the species present in the near shore kelp forest ecosystems of the North Eastern Pacific. This information has been made available in an online database that serves as a clearinghouse for information of this ecosystem. At present, this online database consists of five modules: 1) MySQL database hosted at UCSC, 2) Online data entry interface, 3) Discussion Forum, 4) Dynamic data visualization and 5) Data export function. Species information in the database is temporally and geographically referenced and citation-based to better understand variation in life history, demographic and species interactions. This information will serve as the basis for constructing and parameterizing mathematical models of these species rich communities. Collaborate with us athttp://kelpforest.ucsc.edu/
Beets, J.*, Adolf, J., Colbert, S., Wiegner, T.
COMMUNITY RESPONSES TO NUTRIENT CONCENTRATIONS IN SUBMARINE GROUNDWATER DISCHARGE ON THE KONA COAST, HAWAII
University of Hawaii at Hilo
Groundwater can deliver nutrients to coastal areas essential for coastal production, however, the natural concentrations can be greatly altered by anthropogenic activities causing nuisance algal growth and even phase shifts. On the dry, leeward (Kona) coast of Hawaii island, we have documented pelagic and benthic ecosystem responses to groundwater-delivered nutrient concentrations in two watersheds with greatly different levels of anthropogenic influences and submarine groundwater discharge (SGD). Although groundwater plumes may extent over 1 km offshore and along the coast in a thin layer, greater plankton densities and community metabolism within groundwater plumes extent only a few hundred meters from shore. Benthic algal biomass was not significantly greater within plume zones than in adjacent zones. Benthic grazing activity is intense within the study areas and regulates algal growth and community structure. Coastal development and nutrient concentrations have increased in recent years along with reports of nuisance algal growth at sites along the Kona coast. We recommend enhanced monitoring programs to provide data for management actions in order to avoid deteriorated coastal and reef conditions observed on other islands.
DOES CATCH DATA SUPPORT ANECDOTAL REPORTS THAT MATURE YELLOWTAIL (SERIOLA LALANDI) OVERWINTER IN THE SOUTHERN CALIFORNIA BIGHT?
Scripps Institution of Oceanography – University of California, San Diego
Yellowtail (Seriola lalandi) are highly mobile, predatory jacks found along the Pacific coast of southern California and Baja California, Mexico and are intensely targeted by both Mexican and United States recreational fisheries. Although management of internationally shared resources requires information on migration patterns and essential habitat, this information is largely unavailable for yellowtail.
The Southern California Bight (SCB) is the northern extent of their typical geographic range with peak abundance during May-October. However, fishermen suggest that some of the largest (13 kg) individuals inhabit near-shore waters of the SCB year-round.
To test this, all instances of recreational yellowtail capture in southern California between 1993-2010 were retrieved from existing fishing databases (MRFSS, CRFS), and analyzed by size, season, location, and sea-surface temperature. Catch was bi-modally distributed with peaks at both immature and mature sizes, larger fish were caught inshore (<3 mi) while smaller fish were caught offshore (>3 mi). Additionally, fish caught during winter months were significantly larger than fish caught during the remainder of the year. These differences in geographic distribution and habitat utilization may be a result of differences in life history stages. Elucidating these behavioral differences will greatly assist future management efforts.
Berriman, J.S.1*, Kay, M.C.2, Reed, D.C.3, Wright, W.G.4
PREY DEPLETION IN MARINE RESERVES CONSISTENTLY BROADENS PREDATOR DIET
1 – Dept. Biological Sciences, California State University Los Angeles, 2 – Bren School of Environmental Science and Management, University of California, Santa Barbara, California 3 – Marine Science Institute, University of California at Santa Barbara, Santa Barbara, 4 – School of Earth and Environmental Sciences, Chapman University
By minimizing human impacts, marine reserves can increase the biomass of predators, consequently reducing the biomass of their prey. We hypothesize that these circumstances increase competition and broaden predator diet. One California kelp-forest predator, the spiny lobster Panulirus interruptus, is widely reported to eschew the chemically protected sea hare, Aplysia californica. However, field observations (Goldstein et al., WSN 2009) inside a reserve documented lobsters consuming Aplysia. Here we test (1) the prediction that prey availability is lower inside reserves and (2) whether lobsters consumeAplysia inside three reserves (northern and southern Channel Islands). First, density of the dominant urchin species was significantly depleted inside both southern (Centrostephanus coronatus, 0.0m-2 0 inside, 0.9m-2 0.3 outside, P = 0.0007) and northern (Strongylocentrotus purpuratus, 2.6m-2 0.8 inside, 133.9 m-2 15.2 outside, P < 0.0001) Channel Islands reserves. Second, attacks on Aplysia were observed in all three reserves [% attack sem (number dives): 37% 2 (12), 18% 5 (5), and 16% 2 (5)] but were absent in adjacent off-reserve sites (0 attacks; P1 = 0.0001, P2 = 0.027, P3= 0.0008). These results support our hypothesis that reserves can prompt diet expansion in an important kelp-forest predator.
Blackwell, A.*, Verga-Lagier, A. and Logan, C.A.
FINE-SCALE THERMAL TOLERANCE DIFFERENCES IN MYTILUS CALIFORNIANUS CARDIAC FUNCTION
California State University, Monterey Bay
California ribbed mussels (Mytilus californianus) are a dominant intertidal species ranging from Alaska to Baja California. The species is thought to be genetically homogenous, and yet populations exhibit differences in thermal tolerance across broad latitudinal gradients, even after common garden acclimation. Differences could be due to undetected genetic differentiation, developmental plasticity, maternal effects, or within-site thermal heterogeneity. Given recent evidence that fine-scale thermal heterogeneity in mussel body temperature can rival variation across latitudes, we tested whether mussels living in hotter microsites had higher thermal tolerance than mussels living a few meters away in cooler microsites. Critical heart rate temperature (Hcrit), a sublethal thermal tolerance indicator, was determined for field-acclimatized mussels collected from three 1m2 microhabitats (a low intertidal, and two upper intertidal sites with sunny and shady exposures) at Hopkins Marine Station (Pacific Grove, CA). Mussels were heated (air ramp rate = 8C/hr) to determine the temperature at which cardiac failure occurred (Hcrit). Preliminary data shows significant differences among microsites (ANOVA, df=22, F=6.93, p=0.005), with low intertidal mussels exhibiting lower Hcrits than mid-intertidal mussels (which are not different from each other). Subsequent common-garden acclimation studies will determine whether these differences are due to phenotypic plasticity or another mechanism.
Boles, S1, A. Hettinger2, B. Gaylord2, E. Sanford2, Todgham, A.1
PHYSIOLOGICAL COST OF FUTURE OCEAN CONDITIONS ON LARVAL DEVELOPMENT IN THE NATIVE OLYMPIA OYSTER, OSTREA LURIDA
1 – Department of Biology, San Francisco State University, 2 – Bodega Marine Laboratory, University of California Davis
Since the Industrial Revolution, roughly 48% of anthropogenic CO2 has been absorbed by the oceans, causing a reduction in pH of 0.1 units, and a further decrease of 0.3-0.4 pH units is expected by the end of this century. A great deal of research has been done to predict the future impacts of ocean acidification (OA) on calcifying organisms; however, studies examining the synergistic effects of OA and global warming on the physiological and biochemical processes during early development of calcifying animals are unclear and require further analysis. We reared larvae of the native Olympia oyster, Ostrea lurida, under a factorial combination of CO2 (control, 385ppm vs. elevated, 1000ppm) and water temperature (control, 20C vs. elevated, 24C). To evaluate the energetic costs associated with growth and development under these treatments, we assessed enzyme activity of the Krebs cycle, a proxy for aerobic metabolism. To further investigate cellular transcriptional activity under experimental conditions, RNA to DNA ratios were measured. Larvae reared under conditions of elevated CO2 could face higher energetic demands, leaving less energy available for biomineralization and growth. This in turn could leave less energy available for coping with thermal stress (e.g. ocean warming as well as highly variable thermal habitat of the intertidal zone), possibly impeding survival and settlement of O. lurida. With global climate change, a number of environmental factors are projected to undergo relatively rapid changes; therefore, if we are to predict how contemporary organisms will fair under future ocean conditions, it is pertinent to understand the impacts of climate change from a multi-stressor perspective.
Bonsell, C.E.*, Dayton, P.K.
INVESTIGATING MULTIDECADAL CHANGE IN SAN DIEGO ROCKY INTERTIDAL COMMUNITIES
Scripps Institution of Oceanography
Episodic events often structure ecosystems for long periods and occur across multiple time scales. Community dynamics can change dramatically as a result of large climactic drivers, as seen in ENSO and PDO variability. Trend prediction and ecosystem management are therefore limited for natural systems without the support of observations over such timescales.
This project replicates two earlier baseline rocky intertidal surveys: 1) surveys done in 1961 and 1963 in La Jolla; and 2) surveys done in Ocean Beach, San Diego from 1975-1978. These studies are notable as they precede the PDO regime shift of the late 1970s. By investigating sampling sites examined in the prior studies, we will be able to discern changes to local intertidal community density and tidal zonation. I hope to integrate changes observed with ongoing, but more recent, monitoring by Cabrillo National Monument into slightly deeper time.
BAR-BUILT ESTUARIES IN CALIFORNIA STATE PARKS: ECOLOGY AND RESEARCH NEEDS
California State Parks
A summary of the ecology, key management issues, and the scientific research needs in California State Park estuaries will be presented.
Numerous bar-built or seasonal estuaries occur along Californias coast. Despite the importance of these habitats for steelhead, tidewater gobies, resident and migratory birds, and other species, they are understudied. A summary of the ecology of bar-built estuaries in California State Parks will be presented, including seasonal and geographic variation in habitat characteristics and human alteration.
Are you a researcher or student who wants to conduct research relevant to management? Do you need ideas for research projects or want to see your results applied to management? California State Parks manages 1/3 of Californias coast and state parks contain portions of more than 50 estuaries. Come by the poser to learn about research needs in California State Park estuaries. The poster will address key management issues and the scientific research questions needed to address these issues. Guidelines for research permit requirements and suggestions to facilitate collaboration and work in state parks will also be included.
Bradley, D.E.1, Ridlon, A.D.*2, Gentry, R.1, Mora, C.3, Gaines, S.D.1, Miller, S.J.1, Dee, L.E.1, Peavey, L.E.1, Lester, S.E.1,4
MANAGEMENT MODERATES THE EFFECT OF BIODIVERSITY IN PREDICTING FISHERIES HEALTH
1 Bren School of Environmental Science & Management, University of California, Santa Barbara, 2Department of Ecology, Evolution & Marine Biology, University of California, Santa Barbara,3Department of Geography, University of Hawaii, Honolulu, 4Marine Science Institute, University of California, Santa Barbara
Marine fisheries provide an important source of protein for billions of people globally. As human populations grow, demand for fish is expected to increase, yet reports show a decrease in fisheries production and an increase in stock collapses globally at all trophic levels. A common theme in ecology is that biodiversity stabilizes and drives ecosystem processes and services. In fact, Worm et al. (2006) found that low fish diversity was correlated with lower fisheries production, stability and recovery potential. On the other hand, Mora et al. (2009) found certain attributes of management effectiveness significantly affect differences in fisheries sustainability. Here, we examine the relationship between marine biodiversity and the effectiveness of management regimes on fisheries sustainability, which is a novel contribution. Using both fisheries dependent and independent data at the exclusive economic zone scale, we found that biodiversity consistently and significantly predicts fisheries production, status, and stability and that management often moderates this effect. Our analyses suggest that as countries develop more effective fisheries management strategies, biodiversity becomes a less important predictor of overall fisheries health. Consequently, understanding this relationship between marine biodiversity and effective fisheries management is critical to meeting the global demand for fish protein.
Brett, M.N. 1*, Walsh, K.1, Haggerty J.M.1, Spangler, J.2, Lee, C.2, Harkins, T.2, Edwards, R.1, Thompson, F. 3, Dinsdale, E. A.1
INFLUENCE OF CORAL REEF ORGANISMS ON WATER COLUMN MICROBIAL DIVERSITY
1- San Diego State University, 2- Life Technologies Carlsbad, 3-Federal University of Rio de Janeiro, Brazil
Coral reefs around the world are dying, and a major cause has been associated with a phase shift in community structure where algae outcompetes the coral as the dominant benthic life form. Algae have been demonstrated to kill corals through microbial interactions. To determine how benthic organisms are shaping the microbial communities found in the water column an experiment was performed off the Abrolhos Islands, Brazil where water column microbes were exposed to the effluence of live macro organisms. This was done with four treatments, coral (Siderastrea), crustose coralline algae, a fleshy macroalgae (Stypopodium), and a seawater control. Colony forming units of Vibrios were counted at 6-hour time intervals over a 24-hour period. Changes in the microbial community were assessed by mass sequencing a culture enriched microbial community. The results showed vibrio abundance to be highest in algae treatments. Sequence analysis showed the coral to be distinct from that of other treatments. The microbial communities surrounding the coral are distinguished by having the lowest proportion of Vibriosand the highest proportion of sulfur bacteria and Campylobacter. Benthic organisms are influencing microbial community composition in the water column having a potential negative influence on the health of coral reef systems.
Butensky, M.J. 1*, Marraffini, M. 2
PRESSURE INDUCED ECOLOGICAL EQUILIBRIUM ON THE NATANT INVERTEBRATES OF THE MONTEREY HARBOR
1 University of California Santa Cruz, 2 Moss Landing Marine Laboratories
The Organisms that thrive on the concrete substrates of Monterey Harbor are continuously exposed to pollution, highly variable tides, and maritime traffic that hinder the ecosystems potential to fully thrive. This will select for species that are more able to withstand the continued disturbance and affect the overall diversity of the community. I executed an experiment to determine the effect of different masses on the diversity of these ecosystems. I used two treatment masses, meant to mimic the physical pressure from the harbor traffic and measured changes in percent cover of recruiting invertebrates over time. Based on the literature and the Intermediate Disturbance Hypothesis, I predict that there will be the most diversity of recruited invertebrates as the masses increase. I observed recruitment of sessile invertebrates to the manipulated treatments and an effect of the masses on this recruitment. This experiment ultimately showed how disturbance to artificial structures affects the community that is able to thrive.
Callaghan, M.E.*, Verga-Lagier, A., Kibak, H.
HABITAT PREFERENCE OF THE BAY MUSSEL MYTILUS TROSSULUS IS DISTINCT FROM MYTILUS GALLOPROVINCIALIS AT MOSS LANDING HARBOR, CA
California State University, Monterey Bay
Native populations of the bay mussel Mytilus trossulus continue to decline northward along the coast of California since the arrival in Southern California of a morphologically identical invasive Mediterranean species (Mytilus galloprovincialis) early in the twentieth century. Southern California populations are now apparently entirely the invader while in Moss Landing Harbor (Central California), one can still find a mixture of the native, the invader, and even hybrids. Over the years, sampling to monitor the progress of the invasion in this hybrid zone has routinely occurred on floating docks, presumably because collecting is simplified. However, this habitat is essentially subtidal when contrasted with the intertidal, where the mussels are also found. Is the population of Mytilus spp. found on floating docks at Moss Landing different from the population found in the intertidal and other sites around the harbor? In order to test whether these sibling species exhibit a distinct habitat preference, we use PCR to compare species-specific loci from mussels at floating dock and intertidal sites around the harbor. Preliminary analysis indicates that native mussels tolerate freshwater better than the invader. Sites that are periodically inundated with freshwater may serve as refuges for the native mussel.
Catton, C.A.1*, Rogers-Bennett, L.1,2, Juhasz, C.1,2, Taniguchi, I.2
MODELLING RESTORATION OF ENDANGERED WHITE ABALONE (HALIOTIS SORENSENI) POPULATIONS
1-Bodega Marine Laboratory, University of California, Davis, 2-California Department of Fish and Game
White abalone (Haliotis sorenseni) were listed as endangered in 2001 because of severe declines throughout southern California due to overfishing. According to abundance surveys by NOAA for the last twelve years, the populations are continuing to decline even in the absence of fishing pressure since the closure in 1996. Artificial recruitment modules placed in the Channel Islands and near San Diego have yielded only one white abalone recruit in 2001. A population model fit to the abundance estimates indicates a 14% annual decline since 2000 equivalent to the adult natural mortality rate. This suggests that the populations are reproduction limited and are likely to continue to decline without restoration action. Using a population viability analysis based on the current rate of decline, we estimate that fewer than 1,000 individuals may remain within 10 20 years. Outplanting of captive-reared juveniles is considered the most viable restoration strategy for this species because of the low numbers of remaining wild adults. Researchers from the California Department of Fish and Game, the University of California Davis and Santa Barbara, NOAA, the Aquarium of the Pacific, and the Cabrillo Aquarium are collaborating to initiate a captive rearing and outplanting program in southern California.
Cooper, H.1*, Potts, D1, Paytan A.2
EFFECTS OF OCEAN ACIDIFICATION ON NORTH PACIFIC KRILL, EUPHAUSIA PACIFICA
1 – Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 2 – Institute of Marine Sciences, University of California, Santa Cruz
While many studies have demonstrated negative impacts of ocean acidification on a multitude of calcifying organisms, much less is known about its potential impacts on lightly-calcifying and non-calcifying organisms. Because krill form an important trophic link near the base of many marine food chains, their responses to changing ocean chemistry could have cascading impacts at higher trophic levels (including large fishes, marine mammals and sea birds) and on community and ecosystem dynamics. Laboratory experiments are comparing survival, growth, and molting frequency of a common Monterey Bay krill species (Euphausia pacifica) at two carbon dioxide levels (380 and1900 ppm). Experiments include two temperatures (9oC and 15 oC) to isolate and quantify both individual and synergistic effects of decreasing pH and increasing temperature on E. pacifica. Understanding the effects of future ocean chemistry and temperature changes on such keystone species as E. pacifica is essential for predicting possible ecological consequences and protecting future ecosystems.
MODELING INVASION RISK: COMBINING ENVIRONMENTAL SUITABILITY AND INTRODUCTION LIKELIHOOD
University of California Davis
Invasive species are of key concern to researchers, managers, and policy makers and can be ecologically and economically costly. Assessing invasion risk requires understanding both where a species can exist and the likelihood of that species arriving. Furthermore, future changes to global climatic and socioeconomic landscapes could modify where species are likely to invade. This research aims to develop a model to assess invasion risk for marine and estuarine species that combines species habitat modeling and the likelihood of introduction using New Zealand as a case study. This model combines the use of Maxent for species habitat modeling and the generation of an introduction likelihood landscape based on patterns of commercial shipping; ballast water moved with these ships is a primary vector for novel species entering New Zealand. In particular, methods for selecting layers for use in Maxent are evaluated, comparing a priori and forward stepwise performance methods. Eight marine and estuarine species on New Zealands Unwanted Species Register, including Carcinus maenas and Caulerpa taxifolia, were considered. This model is intended to be a method that can be applied to other locations, including western North America, and modified to reflect changing climatic and socioeconomic landscapes, which could influence invasion risk.
Cramer, A.N.1*, Lindholm, J.B.1, Starr, R.2
WHAT DOES IT MEAN TO BE A HOMEBODY? LARGE SCALE PATTERNS IN MARINE FISH SITE FIDELITY
1 Institute for Applied Marine Ecology at California State University Monterey Bay, 2 Moss Landing Marine Labs
The concept of organismal site fidelity is common throughout the ecological literature, with modifiers such as strong and high frequently added for effect. However, precisely what site fidelity means -strong, high, or otherwise greatly varies across studies. The term is frequently applied to marine fishes, where fidelity can relate either to the frequency of return to a particular location or the percent-time spent at a certain habitat feature. The growing number of studies that use acoustic telemetry to study the movement of marine fishes provides an opportunity for a large-scale investigation of site fidelity and the environmental factors that drive it. We plan to use the tools of meta-analysis to create predictive, multi-species, multi-region models of fish site fidelity using data extracted from published papers. Results from telemetry studies will be analyzed in a variety of mixed effects models and then tested using Akaike’s information criterion (AIC). The resulting models will provide insight into the general movement patterns of marine fishes as well as the underlying drivers of those patterns. Such understanding will help managers to bridge the gap between large scale policy and local management needs.
Davis, A.C.D. 1,2*, Pusack, T.J.2, Hixon, M.A.2
PREDATOR-PREY interactions between INVASIVE Red Lionfish and NATIVE Bridled Goby on Bahamian coral reefs
1 California State University, Monterey Bay, 2– Oregon State University
The Indo-Pacific red lionfish (Pterois volitans) is an invasive, highly efficient predatory species that has recently spread throughout the western tropical Atlantic, Caribbean, and Gulf of Mexico. Previous field experiments in the Bahamas had shown that lionfish can reduce recruitment of reef fishes up to 90%. However, there have been few studies of the effects of invasive lionfish on particular native species. We examined interactions between lionfish and bridled goby (Coryphopterus glaucofraenum), a primary prey of lionfish. Twenty-five lionfish between 4.5 and 23 cm TL were exposed to bridled gobies of incremental size (1, 3, 5, and 6 cm TL) in aquaria, where we recorded time until lionfish detection of the goby, successful and unsuccessful attacks on the goby, and time until full ingestion. We found no consistent size refuge for the bridled gobies from lionfish predation. Lionfish gape size did limit the maximum size of goby ingested (55% TL), yet larger lionfish nonetheless consumed the largest gobies. These results suggest that there may be no natural prey refuge for bridled goby, so that management should continue removal efforts on all sizes of lionfish.
DeBrish, A.M.1*, Magana, C.1*, Brummitt, S.A.1, Epperson, Z.M.1, Adams, N.L.1
EXPOSURE OF ADULT PURPLE SEA URCHINS, STRONGYLOCENTROTUS PURPURATUS, TO SOLAR ULTRAVIOLET RADIATION AFFECTS EMBRYO RESISTANCE
1 – Center for Coastal Marine Sciences, Department of Biological Sciences, California Polytechnic State University, San Luis Obispo
Solar ultraviolet radiation (sUVR) causes physiological stress in marine organisms. Some sea urchin species appear to provide maternal investment to protect offspring from this stress. We examined how exposure of adults to sUVR affects investment in eggs of the purple sea urchin, Strongylocentrotus purpuratus. We exposed adults to or protected them from sUVR for 6 months using Plexiglas filters. We sampled gonads every two months to compare the gonadal index (GI: wet wt. of gonad/wet wt.) between the UV treatments, sex and time. We also compared spawned egg volume between treatments and the amount of UV-induced developmental delays in embryos from the adults exposed to or protected from UVR. There was no significant difference in the GI or volume of eggs spawned between females of the two treatments. Nevertheless, embryos from the UV-exposed mothers experienced lower amounts of UV-induced delays in development than embryos from mothers protected from UVR (P<0.05, n=4). Therefore, exposure to UVR does not affect the volume of gonads, but it alters the maternal investment, conferring greater protection to eggs from UVR. We are currently comparing proteomic profiles among batches of these eggs to identify whether specific proteins differ and contribute to differential resistance to UVR.
Dee, L.E.1,3*, Peavey, L.E.1,3*, Miller, S.J.1,3, Lester, S.E.3, Startz, D.4, Bradley, D.E. 1,2, , Ridlon, A.D. 1,3 , Gentry, R. 1,2
DOES FUNCTIONAL DIVERSITY PREDICT STABILITY AND LEVELS OF GLOBAL FISHERIES YIELDS?
1- Bren School of Environmental Science & Management,University of California, Santa Barbara, 2 – Ecology, Evolution & Marine Biology, University of California, Santa Barbara 3. Sustainable Fisheries Group, UCSB, 4. Department of Economics, UCSB
It is frequently argued that biodiversity impacts ecosystem services such as fisheries production. However, studies have found little to no effect of species richness on global fisheries landings. The relationship between biodiversity and fisheries production remains unclear, complicating attempts to manage fisheries for both production and biodiversity conservation goals. Previous studies defined biodiversity using species richness; however, other metrics like functional diversity (FD) may provide more information about ecosystem functions and services. Here, we analyze the relationship between biodiversity and fisheries yields (mean catch and catch stability) in Large Marine Ecosystems using several biodiversity metrics (e.g. species richness, functional dispersion, and Raos Quadratic Entropy) and combinations of traits (e.g. length, trophic level, depth ranges, etc.) to calculate FD. In addition, we controlled for several variables known to influence fisheries production, such as fishable area, mean annual net primary productivity, and environmental and management characteristics (e.g. sea surface temperature). We found that FD provides more information about fisheries yields than species richness alone, but the direction of the effect depends on the combination of traits considered. Supporting previous results, species richness had a significant effect on mean catch levels even after controlling for other covariates that influence fisheries production.
Desgens-Martin, V.*, Mason, A.Z.
ARE POLLUTANTS INDUCING A CARCINOGENIC CASCADE IN CALIFORNIA SEA LIONS, ZALOPHUS CALIFORNIANUS?
California State University Long Beach
Evidence suggests that exposure of marine mammals to high levels of pollutants might be inducing a carcinogenic cascade explaining the high incidence of cancer in certain species. The goal of this study is to determine whether stranded California sea lions with cancer will exhibit higher tissue concentrations of persistent organic pollutants (POPs), higher activity levels of xenobiotic inducible enzymes, DNA-adducts and other biomarkers of xenobiotic-induced stress than animals without cancer. In order to do so, the levels of xenobiotic pollutants such as PCBs, PAHs and DDTs in the tissues of CSLs with and without cancer, the activity level of cytochrome p450 and other enzymes that have been shown to produce xenobiotic metabolites capable of interacting with DNA molecules and whether there is an increase in the prevalence of DNA adducts in animals having high xenobiotic loading and if these are associated to a higher degree in animals with cancer will be determined. Through this study, we hope to be able to acquire data that will be useful in increasing stewardship efforts along the California coast as well as increase better waste management practices.
Donlevy, C.J.*, Nielsen, K.J.
WILL OCEAN ACIDIFICATION INCREASE THE VULNERABILITY OF ARTICULATED CORALLINE ALGAE TO INTERTIDAL HERBIVORES?
Sonoma State University, Department of Biology
Upwelling brings cold, nutrient replete, low pH waters onto the continental shelf. Shoaled, upwelled waters can have aragonite saturation states low enough to dissolve the mineral form of CaCO3 found in coralline algae. The CaCO3 content of Corallina vancouveriensis was consistently lowest at a site closest to a known upwelling center, suggesting it may already be sensitive to local-scale variation in ocean pH. We hypothesized that reduced CaCO3 content would make articulated coralline algae more vulnerable to herbivory by increasing its palatability or energetic value. We tested this hypothesis using laboratory experiments with two intertidal herbivores, Chlorostoma funebralis and Stronglyocentrotus purpuratus.We compared consumption rates of each on agar and agar with a range of ground up Corallina in it. In a second experiment we compared consumption rates on intact Corallina, decalcified Corallina and the non-calcified red alga Microcladia coulteri. Both herbivores ate more agar with Corallina in it than agar alone. In the second experiment Chorostoma consumed more decalcified-Corallina and Microcladia thanCorallina, while Strongylocentrotus tended to consume more Corallina than Microcladia. These results suggest CaCO3 content alone is not sufficient to explain herbivore consumption rates, and that reduced CaCO3 content increases vulnerability to some, but not all, herbivores.
Downey B.N.1*, Kline D.E.1, Lindholm J.B.1, Rosen D.2, Alfasso A1., Cramer A.1, Fredle M.1, Kelley H.1, Loiacono S.1, Moye J.1, Ramsay E.1, Turner C.1
HABITAT ASSOCIATIONS OF NON-AGGREGATING DEMERSAL ROCKFISHES IN THE BODEGA HEAD MPA REGION: A MULTI-SCALE VIEW
1 Institute for Applied Marine Ecology, California State University Monterey Bay, 2-Marine Applied Research and Exploration
Demersal fishes have been shown to associate with physical (e.g., rocky reefs) and biological (e.g.,structure-forming invertebrates) attributes of the seafloor which they utilize to seek refuge from currents, avoid predators, and enhance prey capture. These habitat associations are known to vary ontogenetically in marine fishes of California. In 2010, a network of Marine Protected Areas (MPA) was designated on the North Central Coast of California emphasizing Ecosystem Based Management. One of the goals was to protect and rebuild nearshore fish populations, which is dependent on an understanding of the spatial scale over which ecological processes occur and the functional relationships between fishes and their environment. By examining relationships between rockfishes and the physical and biological attributes of their habitat from a multi-scale perspective- including micro-, meso- and macro-habitats- using data extracted from remotely operated vehicle imagery and multibeam sonar we can gain a baseline understanding of the relative importance of habitat attributes on the distribution of rockfishes immediately after MPA designation. The information obtained from this study may fine-tune our ability to identify the vital habitat attributes necessary to rebuild depleted populations, as well as contribute to future monitoring plans and the evaluation of MPA efficacy.
Duncan, E. A.1, King, F.2
DO FOOD AND SPACE LIMIT THE GROWTH OR DENSITY OF LOTTIA SCABRA RIDERS ON L. GIGANTEA?
1 – California State University, Long Beach, 2 – Hopkins Marine Station of Stanford University
Along the west coast of North America, the owl limpet Lottia gigantea aggressively maintains feeding territories on rocky shores, actively removing other organisms. Nevertheless, smaller limpets often reside on shells of L. gigantea. We investigated the population structure and ecology of these riders, focusing on the rough limpet L. scabra. The density of riders was significantly higher than that of neighboring non-riders, consistent with the idea that behavioral interactions with L. gigantea may limit local distribution of other limpets. The total numbers and biomass of riders increased proportionately with L. gigantea size and riders were generally smaller than non-riders, suggesting that ridership on L. gigantea may be limited by available space or food. We tested this hypothesis by experimentally reducing shell area available to riders with copper fences. After several weeks, average microalgal biomass had significantly increased on the vacant side and decreased on the occupied side; there was also some emigration, suggesting that individual riders chose to leave in response to this manipulation. Our results suggest that while the shells of L. gigantea may function as a refuge from agonistic interactions for smaller limpets, food and space limitations may result in reduced growth.
Eisenlord, M.E.1, Galloway, A.W.E.1,2, Dethier, M.N.1
FATTY ACID SIGNATURES AND GROWTH IN JUVENILE IDOTEA WOSNESENSKII RESPOND TO DIFFERING MACROALGAL DIETS
1 University of Washington (UW) Friday Harbor Laboratories, 2 UW School of Aquatic and Fishery Sciences
Fatty acids (FA) are commonly used as biomarkers to infer contributions of different basal energy sources to consumers. However, modification, catabolism, and storage of dietary FA are poorly understood for most animals. Controlled feeding experiments are critically needed to determine the appropriate use of FA as dietary tracers. We conducted two such experiments with juvenile isopods to investigate their use as a model organism for FA signature analysis in a direct herbivore. Newly hatched Idotea wosnesenskiiwere raised for 10 weeks on five different macroalgal diets at two different temperatures. Broods were raised from hatching on a single food source. Highest growth rates were on Ulva spp., fresh Nereocystis luetkeana, and aged N. luetkeana. Animals grew significantly slower on diets with chemical (Fucus gardneri) and structural (Mazzaella splendens) anti-herbivore defenses. Temperature did not substantially affect growth rates. Preliminary analyses indicate that FA in Idotea tissues reflect those of their diets, and that FA driving the patterns include common biomarkers for the algae consumed. Juvenile Idotea are a promising model organism for FA trophic ecology because they generally thrive in a laboratory setting and can be hatched and quickly grown on a variety of diets.
Elder, K.B.*, Craig, S.F.
CONTRASTING COPPER TOLERANCE IN TWO ENCRUSTING BRYOZOANS: INVASIVE VERSUS NATIVE SPECIES
Elder, K.B.1 and Craig, S.F.2
1 – Humboldt State University, 2 – Humboldt State University
Antifouling paints are widely used to prevent sessile invertebrates from landing on ship hulls. Some marine invertebrates, however, have developed a tolerance to such paints, indicating their potential to successfully invade by hitch-hiking. This project sought to determine the effects of copper paint on the growth and survivorship of one native (Celleporella hyalina) and one exotic (Watersipora spp.) species of encrusting bryozoans. Larval release of both species was induced in the laboratory. The larvae settled onto plastic sheets which were subsequently placed centrally onto ABS panels previously painted along their borders with anti-fouling paint containing either (1) high, or (2) medium levels of copper. Panels painted with primer (no-copper) served as controls. These panels were then deployed into Humboldt Bay and individual colonies followed weekly for two months. The results showed that copper has negative effects on the growth and survivorship of both species early on, although the native was less affected by copper (in terms of reduced growth and survival) than the exotic species. This surprising result underscores the need for further studies of copper tolerance in multiple species, including surveys of multiple bays, to determine the degree to which the evolution of copper tolerance has become widespread.
Elsberry, L.A.*, Burnaford, J.L.
EFFECT OF RECOVERY TIME ON PHOTOSYNTHETIC PERFORMANCE OF ENDOCLADIA MURICATA FOLLOWING LOW TIDE EXPOSURE
California State University, Fullerton
The high intertidal alga Endocladia muricata is found along the west coast of North America. To determine how populations of Endocladia respond to low tide conditions which vary across the algas extensive range, we collected individuals from Washington and southern California at the high and low edges of the algas tidal distribution in the winter and summer of 2012. We exposed individuals to simulated low tides in which we manipulated thallus hydration state (100% vs. ~50% hydration) and temperature (winter=10oC, 20oC, 30oC; summer=20oC, 30oC, 40oC). We determined the degree of recovery after four hours of low tide exposure by comparing pre-exposure photosynthetic rates to rates measured after three and 24 hours of re-immersion. Multiple factors influenced recovery, and the effects of our treatments differed between regions. Substantial recovery occurred between three and 24 hours of re-immersion; however, because this coast experiences mixed semi-diurnal tides, individuals may be re-exposed after three hours. After 24 hours, individuals at the highest temperatures, regardless of hydration state, had not fully recovered. Understanding how individuals from different populations withinEndocladias range respond to low tide conditions can help us understand how this species may respond to a changing climate.
Epperson, Z.M.*, DeBrish, A.M., Bufo, G., Huang, M.S., Schuman, M.D., Adams, N.L.
LONG-TERM MONITORING OF sea urchin settlement at the Cal Poly Center for Coastal Marine Sciences Pier in San Luis Obispo Bay, CA
California Polytechnic State University, San Luis Obispo
Recruitment of purple and red sea urchins (Strongylocentrotus purpuratus and Strongylocentrotus franciscanus) was documented for five consecutive years by collecting bimonthly settlement samples at the Cal Poly Center for Coastal Marine Sciences (CCMS) Pier facility in San Luis Obispo Bay, California.This project works in conjunction with the statewide project monitoring the settlement of the commercially important sea urchins along the California Coast.The CCMS pierserves as an important sampling station between Fort Bragg and of Point Conception, an important biogeographically dividing line for larval transport and distribution of marine organisms.We monitored sea urchin settlement at multiple depths every two weeks starting January 2008-present. Newly settled sea urchins were counted, measured, identified to species. Settlement of both S.purpuratus and S.franciscanus was observed during each year, but the dominance of species and settlement months has been variable by year. The majority of settlement occurred in the shallow or mid-water brushes, possibly indicating that competent larvae remain higher in the water column prior to settlement than anticipated by previous monitoring efforts.
Fletcher, N.C*, Bell, C.A., Miner, C.M., Orr, D.W., Raimondi, P.T, Redfield, M.A.
BLACK ABALONE HABITAT CHARACTERIZATION AND RESTORATION ON SAN CLEMENTE ISLAND
University of California, Santa Cruz
In 2009, black abalone (Haliotis cracherodii) were listed as endangered under the Endangered Species Act. This species has experienced massive declines along the west coast of California as a result of harvesting, poaching, and the fatal disease Withering Syndrome. In areas that have been decimated by the disease, the adult populations have fallen below the threshold necessary for successful reproduction and subsequent recruitment. Without human intervention, successful recovery of this species will likely be very slow.
In 2011, we conducted a population survey of black abalone on San Clemente Island, CA. Subsequently, in exploration of species restoration strategies, we proposed and began a three tier study to assess and restore black abalone habitat on the island. First, we characterized the available abalone habitat on the island (consistent with previous mainland studies). Second, we determined to what extent adult abalone maintain habitat conditions suitable for recruitment. We compared the community composition of habitat with the presence of one or more adults to suitable abalone habitat void of adults. We found that there was a significant difference between associated communities and we proposed the third tier, restoration of recruitment habitat to conditions consistent with the habitat maintained by adults.
Frantz, D.*, Lowe, C., Young, K.
IMMUNOHISTOSTAINING OF 3B-HSD AND 17B-HSD IN TESTIS OF MALE ROUND STINGRAYS, UROBATIS HALLERI, THROUGHOUT THE REPRODUCTIVE CYCLE
California State University, Long Beach
Gonadal steroidogenesis occurs on a seasonal basis in many elasmobranchs. Because peak plasma testosterone concentrations do not coincide with the breeding season in male round stingrays (Urobatis halleri), we hypothesized that peak steroidogenesis would coincide with maximal testosterone concentrations as opposed to the maximal testis mass observed during the breeding season. As a first step in addressing this hypothesis, male round stingrays, disc width 156-215mm, were collected across the quiescent, recrudescent, and degenerative stages of the reproductive cycle, and levels of two steroidogenic enzymes, 3-hydroxysteroid dehydrogenase (3-HSD) and 17-hydroxysteroid dehydrogenase (17-HSD) were assessed. Testicular immunostaining for 3-HSD and 17-HSD was most prominent in Sertoli and Leydig cells. Compared to other stages, the overall intensity of 3-HSD immunostaining was maximal during recrudescence (p<0.05), whereas overall extent of 3-HSD immunostaining peaked during quiescence (p<0.05). 17-HSD staining was present across all stages, with no seasonal peaks noted (p>0.05). Plasma testosterone concentrations in round stingrays rise initially during recrudescence and peak in the degenerative phase. Data in the current study suggest that 3-HSD follows the seasonal pattern of testis development, as opposed to the cycle of plasma testosterone, which may reflect a novel pattern of gonadal sex steroid synthesis and secretion in elasmobranchs.
GENETIC STRUCTURE OF CORAL-ASSOCIATED NUDIBRANCHS ACROSS THE PACIFIC OCEAN
University of California Los Angeles
In marine environments, there are insufficient geographic barriers to attribute the great diversity of species to allopatric speciation. Coral reefs provide many opportunities for diversification through ecological niche specialization. Previous work on Phestilla nudibranchs suggests that speciation may occur as a result of switching to new coral hosts within the same geographic range. I am continuing this work by examining how geography and coral host influence genetic divergence, both among and within Phestilla species. First I am conducting a phylogeographic analysis of 6 Phestilla species using specimens from Sumatra to Hawaii. Next I will investigate population differentiation within one species, Phestilla minor, collected from multiple coral hosts per location. I will use single nucleotide polymorphisms to detect both neutral and adaptive divergence. Due to limited larval dispersal capabilities I expect neutral markers to show a pattern of isolation by distance, but within sampling sites I expect to see signatures of selection between populations found on different hosts.
Glanz, J.S.*, Bulkin, B.M., Hughes, B.B.
TROPHIC DIVERSITY INFLUENCES GROWTH STRATEGIES AND COMPETITIVE INTERACTIONS IN THE EELGRASSZOSTERA MARINA
University of California Santa Cruz
Biodiversity contributes to the overall stability of ecosystems and their ability to provide important ecological services. Arms races played out by primary producers in their competition for resources can strongly influence the biodiversity of an ecosystem. The outcomes of these arms races are driven by direct and indirect effects of both bottom-up and top-down factors. We investigated how bottom-up (light and nutrients) and top-down (herbivory and predation) factors influence outcomes of this ecological arms race in eutrophic estuarine systems where seagrass and epiphytic algae compete for light. More specifically, we investigated the growth strategies of the eelgrass Zostera marina under two different trophic scenarios using a mesocosm experiment and a comparative survey of Elkhorn Slough and Tomales Bay. Our results demonstrated that when there was a simplified trophic structure (top predator removed), eelgrass abandoned old shoot growth in favor of rhizome elongation and new shoot growth. As trophic diversity increased (top predator inclusion), seagrass was able to outcompete epiphytic algae and allocate resources to old and new shoot growth as well as rhizome elongation. Given that seagrass provides many essential ecological services understanding this arms race is important for assessing how this ecosystem is shaped and its health is maintained.
Gonzlez, A.V.1 Borras-Chavez, R.2*, Vsquez J.A.3, and B. Santelices2
DETECTING NATURAL CHIMERISM IN TWO LESSONIA SPECIES (PHAEOPHYCEAE)
1-Universidad de Chile, 2-Pontificia Universidad Catlica de Chile, 3- Universidad Catlica del Norte
Coalescence is the process that allows fusion between two or more individuals forming a genetically heterogenic entity known as chimera. In brown algae, holdfast fusion has been shown at intra-especific level in Lessonia spicata and L. berteroana, but its frequency is unknown under natural conditions. In this study, the existence of coalescence in natural populations of these two species was quantified by measuring the frequency of individuals with genetically heterogenic stipes within the same holdfast. Juvenile individuals of each species were collected and a genetic characterization was done in all the stipes of each holdfast. Results indicate presence of chimerism in both species, genetic heterogeneity increasing directly with the increasing number of stipes. Difference in the degree and frequency of natural chimerism between species was found. L.spicata showed a lower number of genetically distinct stipes per holdfast than L. berteroana, with a lower number of polymorphic alleles and consequently, a lower frequency of chimerism (L.spicata: 43% and L. berteroana: 93%). These results suggest that the frequency of chimerism in this group of algae could be species-specific and sometimes it could reach high frequency in natural populations (e.g. L.berteroana).
SEASONAL, GEOGRAPHIC, AND ONTOGENETIC FEEDING ECOLOGY OF EASTERN PACIFIC ANGEL SHARKS
University of California, Los Angeles
Angel sharks are primarily benthic dwelling sharks found mainly in temperate and sub-tropical parts of the Atlantic and Pacific Oceans. Their primary method of capturing prey is by ambushing anything small enough to be swallowed by rapidly lunging from a sedentary position on the sea floor. In the eastern North Pacific angel sharks are thought to be generalists predators that exhibit geographic variation in their diet compositions in different environments across their range. In the Southern California Bight blacksmith (Chromis punctipinnis) are the most prevalent prey and in the Southern Gulf of California jack mackeral (Decapterus macrosoma) are the most prevalent prey item. Curiously, no significant ontogenetic shifts in diet have been previously documented, which would suggest that the sharks might exhibit a local preference for a particular species. In this study the stomach contents of 71 angel sharks from across the Pacific Ocean and the Gulf of California surrounding the Baja California peninsula were examined and used to describe patterns of seasonal, geographic, and ontogenetic feeding habits of these sharks across their range.
Haas, A.F.*, Deheyn, D.D., Smith, J.E.
EFFECTS OF REDUCED DISSOLVED OXYGEN CONCENTRATIONS ON PHYSIOLOGY AND FLUORESCENCE OF HERMATYPIC CORALS AND BENTHIC ALGAE
Scripps Institution of Oceanography, University of California, San Diego
While shifts from coral to seaweed dominated ecosystems have increasingly been reported and factors triggering these shifts successively identified, the primary mechanisms driving these interactions are still subject to speculation. Amongst various potential mechanisms, algal exudate mediated increases in microbial activity could lead to localized hypoxic conditions, which may cause coral mortality in the direct vicinity. While most of the processes potentially causing algal exudate induced hypoxia have been identified, little is known about how low dissolved oxygen concentrations would affect competitive dynamics between seaweeds and corals. Therefore, this study investigated the effects of different levels of oxygen on the common Pacific coral, Acropora yongei, and the siphonous green alga Bryopsis pennata.Specifically, we examined how photosynthetic oxygen production, quantum yield, intensity and anatomical distribution of coral innate fluorescence, and visual estimates of health varied with differing nighttime oxygen conditions. Results showed that the alga was significantly more tolerant to extremely low oxygen concentrations (<4 mgL-1) than the coral. Corals could tolerate reduced oxygen concentrations only until a given threshold. Exceeding this threshold led to rapid coral tissue loss and mortality. This study indicates that hypoxia could indeed play a significant role for the outcome of coral-algae interaction processes.
Hackitt, J.D.*, Steele, M.A.
EFFECTS OF LUNAR PHASE ON SETTLEMENT RATE OF TWO TEMPERATE REEF FISHES
California State University, Northridge, Department of Biology
Settlement rates of some reef fishes are known to differ among lunar phases, but relatively little is known about how lunar phase affects settlement rates of temperate reef fishes. This study examined the effects of lunar variation on settlement rates of two temperate reef fishes at Santa Catalina Island, California. We quantified the abundance of recently settled seorita (Oxyjulis californica) and blacksmith (Chromis punctipinnis) along transects at two study sites during each lunar phase from June-September. SCUBA divers swam along 50-m transects placed parallel to shore in the inner, middle, and outer portion of the reef, recording the abundance of larvae at three depths: bottom, middle, and surface. Larval settlement for seorita showed no lunar pattern, having similar densities during all four lunar phases. Blacksmith, on the other hand, had significantly higher settlement during the 1st Quarter and Full moons. Settlement of seorita did not appear to be related to water temperature or tidal amplitude, but blacksmith settlement tended to be related to these factors. Patterns in settlement for both species might be less driven by physical factors than by biological factors like adult spawning strategies, which affect the timing of reproductive output.
Haggerty, J. M. *, Dinsdale, E. A.
ECOLOGICAL SCALE OF MICROBIAL BIODIVERSITY
San Diego State University
In marine systems microbial communities act as nutrient cyclers, pathogens, indicators of settlement, sources of toxins and symbionts. Metagenomics has allowed rapid advancements in microbial studies of archaeal and bacterial communities through mass sequencing of random fragments of environmental DNA and assignment of closest similarities to known taxonomic and functional genes. Because microbes function at the micrometer level, the appropriate ecological scale to measure microbial diversity is debated. To determine variability of marine water column microbes, samples from a meter bellow the waters surface are compared to paired samples of southern kelp forest systems and across a global survey. Global analysis shows distinct oceanographic differentiation of community diversity and function. Southern California kelp forests show a distinct taxonomic diversity with higher proportions of Proteobacteria and Firmicutes in La Jolla than neighboring Pacific Beach and Point Loma kelp forests. Functional diversity is more consistent in kelp forest systems when compared to marine communities across the globe. Significant differences in genes encoding virulence and metabolism of sulfur, potassium and aromatic carbons were found between kelp forests and samples from Galapagos, coral atolls and the Indian Ocean. Findings indicate that diversity of marine surface waters becomes increasingly homogeneous with smaller sampling areas.
RESEARCH AT A TRIBAL COLLEGE
National Indian Center for Marine Environmental Research and Education, Northwest Indian College
Working with tribal communities brings a new prospective to ecological questions and a long-term view of natural resources. However, it is often a long and difficult process to find collaborators in tribal communities. One way to achieve meaningful interactions with tribal communities is by working with Tribal Colleges and Universities (TCUs). TCUs were created in response to the higher education needs
of American Indians and combine personal
attention with cultural relevance. Successful research at tribal college starts with framing proposed work within the Vision of the Ancestors. Research must be grounded in both traditional knowledge and Western science. Examples of research at Northwest Indian College that bridges this divide are determenation of a pre-Eurpean ecological baseline based on traditional knowledge and investigating traditional clam preperation methods as a method to reduce consumption of biotoxins. Guidance and a framework for further collaboration between tribal colleges or tribal communities and outside organizations will be presented.
Heldt, K.A.*, Childress, M.J.
THE INFLUENCE OF AGGRESSION AND HABITAT LOSS ON JUVENILE CARIBBEAN SPINY LOBSTER (PANULIRUS ARGUS) DENNING BEHAVIOR
Spiny lobsters are highly gregarious and use shelters for protection from predators. In recent years, sponge loss events in Florida Bay have decreased the amount of natural shelters available for juvenile spiny lobsters. However, den use, den sharing and lobster numbers have remained relatively constant suggesting that aggression and den competition may have increased. To estimate the role of aggression on denning behavior, individuals were size-matched and housed as pairs in an aquarium with a single crevice shelter and total number of aggressive acts were measured by direct observation. Then, ten pairs of marked individuals were observed daily in a mesocosm with 10 crevice shelters. On day four, five crevice shelters were removed to study the impact of sudden shelter loss. We measured the frequency of den use, den sharing and den fidelity of each individual before and after shelter loss. We found that aggression was highly correlated with size and that large, aggressive lobsters exhibited less den sharing. Surprisingly, when shelter number was reduced, den sharing remained constant but den use and den fidelity decreased for large, aggressive lobsters. These data suggest that vulnerability rather than aggression predicts which individuals remain in a den after sudden shelter loss.
Holder, A.M.1,2*, Zeidberg, L.D. 3
IMPACTS OF HYPOXIA ON HATCHING SUCCESS OF MARKET SQUID (DORYTEUTHIS OPALESCENS)
1 – Hopkins Marine Station of Stanford University, 2- California State University Monterey Bay, 3 – California Department of Fish and Game, Environmental Services Division
Developing benthic egg capsules of the California market squid in southern Monterey Bay are exposed to natural hypoxic events during development. Here we exposed capsules to two hypoxic treatments that were based on long-term measurements of dissolved oxygen (DO) concentration and temperature near a local squid spawning ground: three 6-hour exposures to 1 mgL-1 DO or two 24-hour exposures to 3 mgL-1DO. Overall percent of successfully hatched paralarvae was comparably high for both control (98.9 0.3, 98.2 0.4) and treated capsules (95.7 0.3, 97.4 1.1) exposed during early (stages 2-5) and late (stages 24-29) stages of embryonic development, respectively. However, recently hatched paralarvae from hypoxia-challenged capsules tended to be lethargic as evidenced by general inactivity and a lack of active swimming. These observations suggest that transient hypoxic episodes during development may lead to post-hatching behavioral deficits that adversely affect survivability. Considering D. opalescens is both ecologically and economically important in California, and that climate change may lead to an increase in nearshore hypoxic events on the Pacific coast, the sensitivity of developing squid eggs to hypoxic challenges will likely become an increasingly important issue.
EFFECTS OF TEMPERATURE ON SEXUAL COMPETITION IN KELPS
Moss Landing Marine Laboratories
Kelp forests are diverse and productive ecosystems, yet kelp populations often exist close to their temperature tolerances and changes in temperature may affect kelp population persistence. Researchers have investigated how temperature change impacts kelp recruitment, but it is unknown whether temperature changes will affect interactions between microscopic life stages of different kelp species. Differential timing of gametogenesis among kelp taxa can lead to competitive interactions between microscopic stages, influencing recruitment patterns. To address one of the potential impacts of climate change, I investigated how temperature shifts may affect chemical competition between microscopic stages of two co-existing and possibly competitive kelps. Laboratory studies were conducted to test the effects of changing temperatures on germination, gametogenesis, and fertilization of Macrocystis pyriferaand Nereocystis luetkeana from their overlapping range.
Jacobsen-Watts, E.*1, Lowe, A.2, Duggins, D.O.2
INFLUENCE OF WATER SOURCE MIXING ON PHYTOPLANKTON COMMUNITY IN A NEARSHORE ENVIRONMENT
1 University of Washington, Seattle, 2 University of Washington Friday Harbor Laboratories
Phytoplankton are an important component of the particulate organic matter (POM) available to suspension feeders within nearshore habitats. The Salish Sea in Washington State is a dynamic, tidally-driven system characterized by the mixing of oceanic- and riverine-water masses. Density differences between these water sources leads to stratification and a better growing environment for phytoplankton; however, stratification is intermittent and depends on tide cycle. We observed phytoplankton community and environmental conditions over 24 hours during a spring tide series in May to quantify changes in POM related to mixing of water sources. Visual analysis showed increased phytoplankton abundance during high ebb and flood currents, and different communities were seen on ebb and flood tides. Skeletonema spp. was most numerous across samples, averaging 54.5% of the total phytoplankton count per tow. Stable isotope signatures (d13C, d15N, d34S) were strongly correlated to chl a concentration. We also found variation in fatty acid signatures over the tide cycle, reinforcing our conclusions about changes in POM components with water masses. There is thus considerable variability in phytoplankton communitys composition within the water column over a short period of time; movement or growth of phytoplankton are greatly influenced by water-source interactions on small temporal scales.
Jarrell, S.C.*, Dayton, P.K.
EFFECTS OF STORM DRAIN EFFLUENT ON INTERTIDAL MICRO-INVERTEBRATE SURVIVAL
Scripps Institution of Oceanography, University of California at San Diego, California
Concrete and asphalt are pervasive in urban communities and these design features result in a high volume of storm runoff along the coast. Further, typical urban runoff collects anthropogenic pollutants such as brake dust and pesticides before it enters intertidal zones. The consequences of storm drain effluent on micro-invertebrates that inhabit intertidal communities are not well understood, but their ecological roles (as bacterial grazers, filters, and prey) are significant, so pressures exerted on them by pollution are important. To assess the effects of storm water discharge on intertidal micro-invertebrates, we conducted in situ and ex situ experiments during a storm event in La Jolla, California. Micro-invertebrates located within storm-water-exposed sites and reference sites were assessed for survivability upon conclusion of the storm. Preliminary results indicate micro-invertebrate survival was lowest near the storm drain; however, micro-invertebrates exposed to clean fresh water in the laboratory also showed depressed survivability, similar to micro-invertebrates exposed to storm water, whereas storm water salted up to normal salinity resulted in high survivability. These findings suggest that the exposure to fresh-water may be primarily responsible for micro-invertebrate morbidity in areas exposed to storm runoff.
Johnson, A.*, Menge, B.
UNUSUAL INCREASE IN ABUNDANCE OF AN INTERTIDAL SPONGE: CLIMATE CHANGE, NATURAL CYCLE, OR?
Oregon State University
Although sponges can be superior competitors in cryptic habitats under continuous submersion, they are typically sparse in rocky intertidal habitats. For example, the sponge Halichondria panicea is typically present in low intertidal habitats, but is usually at low abundance and limited to crevices, holes, and other cryptic habitats. Unusually, since 2007, abundance of H. panacea at Fogarty Creek on the central Oregon coast, has increased from 7.3 + 1.3% cover (mean + 1SE) to 25.6 + 3.7% cover in 2012. Similar changes have been observed at another site, Yachats Beach. Such change could result from processes associated with climate change, with normal climatic or other cycles, or their interaction. We examined change in phytoplankton abundance and temperature, and found no comparable trend in either factor. Another alternative is the 18.6 year lunar phase known as the Metonic Cycle, which can alter tidal ranges and temperature patterns with impacts on intertidal community structure. We found that the increase in sponge abundance coincides with average yearly increases in mean low low water, suggesting that time of submergence of low zone sponges has increased, thereby providing reduced thermal stress and more feeding time. Although long term phases such as the Metonic Cycle should be considered when evaluating the impact of climate change, we did not observe similar changes in the mid 1990s, suggesting that other factors may also be in play.
Jones, E1,2*, Long, J.D.1
HERBIVORE-INDUCED CHANGES IN PALATABILITY DO NOT ALTER NUTRIENT UPTAKE RATES OF THE INTERTIDAL SEAWEED SILVETIA COMPRESSA
1 – San Diego State University, 2 – University of California, Davis
Biotic interactions among species may serve as important mediators of ecosystem functioning, as these processes are based on feedbacks between species physiologies, community-level interactions, and energy transformation. For example, herbivores may cause changes in plant or seaweed traits that alter physiological processes such as photosynthetic rate, nutrient cycling, or carbon uptake, in turn, influencing biogeochemical processes. In this study, we investigated whether herbivore-induced changes in palatability altered nutrient uptake rates in the seaweed Silvetia compressa. We predicted that uptake rates would increase so that energy could be allocated to seaweed defense and wound repair. Following a two-week induction phase where Silvetia thalli were grown with and without the snail Chlorostoma funebralis, we measured nutrient utilization to test whether herbivore grazing influenced nitrate uptake rates. We also performed a paired-choice feeding assay between grazed and ungrazed tissues to assess changes in palatability. Despite noticeable grazing marks on herbivore-exposed seaweeds, and a significant snail preference for non-grazed tissues over grazer-damaged ones, there were no indirect effects of herbivory on nutrient uptake parameters. Thus, these data suggest that herbivore-induced defenses do not cause compensatory increases in nitrate uptake and have little effect on nitrogen cycling.
Kloppe, R.E.1,2*, Loke-Smith, K.A.1, Jarvis, E.T.1, Young, K.A.2
IMPROVED ESTIMATE OF SPAWNING FRACTION AND INTERVAL FOR BARRED SAND BASS, AN AGGREGATIVE SPAWNER IN SOUTHERN CALIFORNIA
1 – California Department of Fish & Game, 2 – California State University Long Beach
The previous spawning fraction and spawning interval estimate for female barred sand bass (Paralabrax nebulifer) was based on fish collected during mid-spawning season. To determine if these estimates vary across the entire spawning season, we quantified ovarian activity using histological cross-sections from P. nebulifer females collected on the San Pedro Shelf from June to September 2011 (n=208). The spawning fraction (S) was estimated using the postovulatory follicle (POF) method to determine the proportion of mature females with POFs 4-24 hours old. The spawning fraction varied by month (2 (3, N =208)=10.34,p<0.02) with the proportion of spawning females peaking in July and August, although no difference was noted between these two months (2 (1, N =166)=2.19, p>0.1). The spawning fraction ( 95% CI) during July and August was 0.42 0.08 and the average spawning interval was 2.37 days with daily spawning in 42% of fish. In contrast, POFs were less abundant in June (S=0.13 0.14 95% CI) and September (S=0.06 0.14 95% CI), indicating spawning was infrequent during those months. These improved reproductive estimates provide the framework for a future stock assessment, increasing our ability to manage this popular sport fishery.
Koenigs, C.1*, Miller, R.J.2, Page, H.M.2
TROPHIC RELATIONSHIPS IN THE KELP FOREST CANOPY
1 University of Central Oklahoma, 2 Marine Science Institute, University of California Santa Barbara
Many small mobile and sessile invertebrates inhabit the dense canopy of kelp forests, which provides physical habitat and also offers a potential food source. Some crustaceans and mollusks graze on kelp, while suspension feeders such as hydroids and bryozoans feed on suspended particulate organic matter (POM) largely composed of phytoplankton. Kelp forest fishes prey on these canopy dwellers in addition to pelagic zooplankton and benthic invertebrates. We are evaluating the relative contributions of carbon derived from kelp and POM to the diet of canopy fishes using stable isotope analysis (SIA) of invertebrate prey and selected fish, supplemented with stomach content analysis (SCA). Mixing models were used to estimate contributions of 1) POM and kelp carbon in invertebrates and 2) suspension feeders and kelp grazers in fishes. Kelp grazers were clearly distinguished from suspension feeders based on isotope composition. SCA identified suspension feeders (hydroids and bryozoans) and kelp-grazing invertebrates (amphipods and isopods) as the two potential nutrient sources for the fish species examined. SCA showed that kelp rockfish (Sebastes atrovirens) specialized on kelp grazers, whereas the blue rockfish (Sebastes mystinus) fed mainly on suspension feeders. SIA results reflected this specialization. Results for other fishes thus far suggest a mixed diet.
Korcheck, K.M.*, Succow., M., Guerrero, A., Craig, S.F.
POPULATION VARIATION IN TEMPERATURE TOLERANCE IN A WIDELY INVASIVE SPECIES COMPLEX,WATERSIPORA (BRYOZOA)
Humboldt State University
Marine habitats are under increasing threat of invasion by exotic species, which cause extensive damage to ecosystems. Cryptic yet genetically distinct bryozoans in the genus Watersipora have invaded bays throughout California and show a distinct geographical pattern of invasion, with clades new species and A found more frequently in northern and southern California, respectively. This suggests that invasions may depend on water temperature. To test whether clades within this species complex have evolved different temperature tolerances, we collected colonies of new species and A from five bays along the California coast and induced them to release larvae at the Telonicher Marine Lab. Newly settled larvae were then subjected to two environments representing average summertime water temperatures in northern (11 C) and southern (18 C) California. After 17 weeks, both clades grew significantly better in cold water. However, as we predicted, more northerly (new species) colonies performed poorly in warm water, and more southerly (A) colonies grew significantly larger than new species in warm water. Finally, mortality of clade A was highest in cold water. These results suggest that differences in growth and survival of cryptic species of Watersipora may help explain their pattern of invasion.
Kolosovich, A.S. 1,2, C.L. Kitting2*
NUTRIENT EXCRETION BY NATIVE ANODONTA FRESHWATER MUSSELS COEXISTING WITH Corbicula INVASIVE CLAMS IN A SAN FRANCISCO RESERVOIR
1-San Francisco Public Utilities Commission, 2- Cal State Univ. East Bay
Freshwater bivalves often are ecosystem engineers, at high densities influencing lake ecosystems. Mussels filter water columns, excreting nutrients in urine and feces, with ammonium and phosphorous compounds that limit lake primary productivity. Many nutrient cycling experiments focus on invasive species; fewer studies focus on native freshwater mussels, often rare now. Unionid mussels are being extirpated from much of Western North America, with unknown consequences. InSan Andreas Reservoir,a drinking water reservoir south of San Francisco, high population densities of each of these two bivalves occurred in the reservoir depths: native Anodonta (californiensis / nuttaliani ) mussels plus invasive Corbicula flumineaclams. Per gram of shell-free dry weight, Anodonta mussels excreted an average of 5~10 ug NH3 per hour per gram of mollusk, and 2~7 ug PO4 /g/hr. Unlike previous reports with Corbicula invasive clams, smallAnodonta mussels, per gram of mollusk, excreted 52% more NH3, and 330% more PO4 than large Anodontamussels. Per gram of mollusk, Corbicula excreted 87% more NH3 than Anodonta mussels, but Anodontamussels excreted 46% more PO4 than Corbicula. At these high population densities, among dense aquatic plants here, these bivalve populations may contribute much nutrient cycling.
Kowalski, B.L.*, Watson, F.G.R.
EFFECTS OF LANDSCAPE COVARIATES ON THE DISTRIBUTION OF MAMMALIAN CARNIVORES ON THE FORT ORD NATIONAL MONUMENT
California State University Monterey Bay
Urban expansion and increased anthropogenic activity in preserved habitat areas may cause changes to current spatial distribution of mammalian carnivores. We collected detection/non-detection data for coyotes, grey foxes, raccoons, and skunks using scent stations and modeled their current occurrence across Fort Ord National Monument as a function of urban proximity and road/trail density.We incorporated the probability of detection into logistic regression models, and ranked the models using AIC for each species. Domestic dogs were more likely to use areas closer to the urban edge, while grey foxes showed a preference toward inland areas with higher road/trail densities. Striped skunks demonstrated higher detection probability in areas closer to the urban edge,while raccoons had a higher detection probability in areas with high road/trail densities. The best model for coyotes was the null model, demonstrating coyotes’ wide use of the Fort Ord landscape. Our results suggest that the distribution of domestic dogs will most likely expand with future development, while those ofgrey foxes will contract. We conclude that future land use changes will most likely have a varied affect on the distribution of mammalian carnivores, and that careful consideration is needed to ensure those species healthy populations.
Kulesza, K.M.*, Galloway, A.W.E., Duggins, D.O.
INDICES OF NUTRITION WITH DEPTH IN TWO PACIFIC NORTHWEST INVERTEBRATES
Friday Harbor Laboratories, University of Washington
Drift algal material has been thought to play a significant trophic role in ecosystems near kelp beds. The role of drift algae to the overall nutritional state of various invertebrates can be assessed using phenotypic traits such as gonad index (larger gonad mass with better nutrition) and for sea urchins, the additional factor of jaw diameter (larger jaws with inconsistent food supplies). In this study, we collected green urchins (Strongylocentrotus droebachiensis) and giant barnacles (Balanus nubilus) within kelp beds (5m depth) in the shallow subtidal photic environment (SSPE) and the deep subtidal environment (DSE; 100m depth). Urchins in the DSE had significantly larger gonads and but also larger jaws than SSPE animals. These results suggest that urchins in the DSE have more food or better quality diets. However, the jaws from DSE urchins suggest that the food supply may be inconsistent. Potential explanations include a subsidy from algal material exported from nearby kelp beds, or increased omnivory in DSE urchins. The barnacle gonad index did not differ between depths, suggesting that the quantity and/or quality of particulate organic matter was equal at both depths. Because suspension feeders consume primarily plankton, the good nutritional state of the DSE animals was unexpected.
Kwan, C.K.1,2*, Long, J.D.1, Sanford, E.2
TESTING FOR COMMUNITY-LEVEL EFFECTS OF COPPER POLLUTANTS ON AN ESTUARINE TRI-TROPHIC SYSTEM
1 – Coastal and Marine Institute Laboratory, San Diego State University, 2 – Bodega Marine Laboratory, University of California Davis
Increasing anthropogenic pollutants pose immense threats to marine ecosystems. Previous research has emphasized the lethal consequences of exposure of individual organisms to pollutants, such as copper. Although we understand some of the lethal and nonlethal effects of pollutants on individuals, we lack an appreciation of how pollutants affect species interactions. For example, the influence of pollutants on chemically-mediated interactions is rarely studied despite the prevalence and importance of such behaviors (e.g., avoiding predators, and finding food or mates via chemical cues). We studied the impact of pollutants on trait-mediated indirect interactions and prey inducible defenses in a tri-trophic system in Bodega Harbor, CA. We conducted experiments to test the influence of pollutants on the nonlethal effects predatory crabs (Cancer antennarius) have on whelk prey (Nucella ostrina) and their barnacle basal resource. In the field, we quantified the effects of predatory cues on whelk predation and growth at two sites that differed in pollution levels. In the laboratory, we examined whelk predation and behavior under different crab cue and copper treatments. Copper at concentrations currently found near docks and marinas around the U.S. may affect organisms not only at the population level but also cause community-wide effects.
Larson, M.A*, Jenkinson, R.S., Hovel, K.A.
URCHIN MORTALITY IN KELP FORESTS: RELATIVE ROLES OF SPINY LOBSTERS AND SHEEPHEAD
Department of Biology and Coastal & Marine Institute, San Diego State University
Predatory or consumer interactions in marine systems, set within the context of physical forcing and abiotic variation, can have large scale impacts on population dynamics and community structure. Within subtidal reefs south of Point Conception, California, California spiny lobster and sheephead are thought to be the primary predators capable of controlling sea urchin populations, and thus community structure. The goal of our project is to determine the relative impact of these two predators on urchin mortality. We conducted six monthly urchin tethering trials in the Point Loma kelp forest near San Diego (May – October 2012) and identified the predators responsible for purple urchin mortality via observation and examination of urchin test remains. At the beginning of our experiment, sheephead contributed more to urchin mortality than did spiny lobsters. As the months have progressed, however, mortality from sheephead has declined and mortality due to lobsters has increased. Trends in relative predation rates matched trends in density for these two predatory species on our transect surveys. Our results shed light on how community level interactions vary over a temporal gradient. By understanding community level interaction, conservation efforts can focus on each important species throughout the year.
Lewis, L.S.*, Smith, J.E., Price, N.N.
BIOPHYSICAL CHARACTERISTICS AND THE DEVELOPMENT AND GROWTH OF SHALLOW FRINGING CORAL REEFS IN MAUI, HAWAII
Scripps Institution of Oceanography
Numerous factors are known to influence the growth and development of coral reefs. Because of their complexity, there is little consensus among the scientific community regarding the primary factors that determine reef community structure and net reef growth (CaCO3 accretion). The importance of physical and biological factors likely varies in space and time, and therefore, needs to be examined in order to understand the factors influencing the development of any specific reef ecosystem. We used standardized tiles known as calcification/accretion units (CAUs) to explore community development and calcification on shallow (2-3 m) coral reefs in Maui, HI. Ten caged and uncagedCAUs (20 total) were installed at each of eight sites that spanned 60 km of Mauis leeward coastline. A suite of biophysical parameters (including herbivore abundance, pH, temperature, light availability, nutrients, sedimentation, microbe density, flow, and dissolved organic carbon) were then monitored for 12 months and compared to community development, and eventually net accretion, on tiles both exposed to and removed from grazers. Results of this work will shed light on the ranges of numerous biophysical parameters in Mauis nearshore reefs, and how variation in these parameters correspond to the development and growth of benthic coral reef
Lindholm, J.B.1, Gleason, M.G.2, Kline, D.E.1, Clary, L.M.1*, Reinecke, S.J.2
The ecological effects of bottom trawling in unconsolidated sediments: A Directed trawl impact study off Morro Bay, California
1 Institute for Applied Marine Ecology at CSU Monterey Bay, 2 The Nature Conservancy
Fishing with bottom trawls impacts both the seafloor and associated biological communities and has been well documented, particularly in hard-bottom communities. However, less is known about the effects and duration of impacts in unconsolidated sediments where bedforms and structure-forming invertebrates provide fish habitat. We collaborated with the commercial fishing community in Morro Bay, California to conduct experimental bottom trawling along the 170 m isobath near Point Buchon, California. Controlled experiments were conducted over three years, at two different intensities. We trawled four of eight plots at low-intensity the first year (covering the entire plot area 2.5 times) and high-intensity (5 times) at those same plots the second year. A remotely operated vehicle (ROV) collected video and still imagery of the seafloor and associated biological communities before trawling and 2-weeks, 6-months, and 1-year post-trawl. Data extracted from the imagery showed declines in micro-topographic complexity under both low- and high-intensity trawling treatments. However, a lack of significant differences between trawled and un-trawled plots with respect to structure-forming (sea whips and pens) and mobile invertebrates (octopus, crabs, and stars) suggests that considerable natural variation in the benthic community must be considered when evaluating the impacts of trawling communities.
Lindstrom, S.C.*, Hervieux, M.
PHYLOGEOGRAPHY OF SPECIES OF THE MAZZAELLA OREGONA CLADE (GIGARTINACEAE, RHODOPHYTA) IN THE NORTHEAST PACIFIC
University of British Columbia
We examined genetic variation among isolates of species in the Mazzaella oregona clade: M. oregona, M. parksii, M. phyllocarpa, and Mazzaella sp. (this species has been described, but a new combination has yet to be made in Mazzaella) using the nuclear ribosomal ITS region, the chloroplast rbcL gene, and the mitochondrial COX1 barcoding gene. Mazzaella oregona, distributed from southern California to Kodiak Island, Alaska, shows little genetic variation except for a distinctive genotype found in individuals from the eastern Strait of Juan de Fuca in southern BC – northern WA and near Prince Rupert in northern BC. Populations of Mazzaella parksii, distributed from Mendocino Co., CA, to the westernmost Aleutian Island, AK, show significant differentiation between southeastern populations (from southern Oregon to the Kodiak archipelago, AK) and northwestern populations (from the Kodiak archipelago to Attu Island, AK).Mazzaella phyllocarpa, recorded from Russia to Southeast Alaska and north to St. Lawrence Island in the Bering Sea, shows some genetic variation among Alaskan specimens, but there is no geographic pattern to this variation. Mazzaella sp., distributed from the Commander Islands, Russia, to northern Vancouver Island, British Columbia, also shows some variation among individuals but with little geographic pattern to this variation. These results resemble those for other northeast Pacific organisms in that the high intertidal species showed the most phylogeographic differentiation, and a biogeographic break appears in the northwestern Gulf of Alaska for at least one of the species.
Low, N.H.N.1,2*, Witman, J.D.2
FUNCTIONAL ROLES OF SEA STARS IN THE GALAPAGOS MARINE RESERVE
1 Hopkins Marine Station, Stanford University, 2 Brown University
Galpagos sea stars are a highly diverse group and contribute significantly to standing biomass in their subtidal communities, yet little is known of their functional roles. Recent preliminary evidence indicates that one species, Pentaceraster cumingi, may function as a predator of the pencil urchin, an abundant and important grazer in this system. I examined the diversity of trophic roles among six common Galpagos sea stars (Asteropsis carnifera, Mithrodia bradleyi, Nidorellia armata, Pharia pyramidata, Phataria unifascialis, and P. cumingi) using feeding surveys at 12 sites to characterize their diet compositions. In addition, I used a predator inclusion experiment to examine P. cumingi‘s potential role in predatory control of pencil urchins. Multivariate analyses showed that sea star diets were characterized by a high prevalence of herbivory among species, but also showed key differences between species, with predation of sessile wall invertebrates, deposit feeding, and urchin predation found in different species. P. cumingiwas the only species observed preying on pencil urchins in the field, and exhibited high per-capita rates of predation on small and large size classes of urchins in the predator inclusion experiment. These findings indicate high functional diversity within the asteroid taxonomic group in the Galpagos, and implicate P. cumingi as a potentially important component of urchin population control and trophic cascades in this system.
McCartha, M.M.*, Gawel, J.E., Becker, B.B.
METALLOTHIONEIN AS A BIO-INDICATOR OF METAL TOCIXITY IN PUGET SOUND, WA
University of Washington, Tacoma
Metallothionein (MT), is produced by benthic invertebrates in response to metal pollution, and as such provides a valuable tool for monitoring metal pollutant impacts on aquatic communities. In this study, we are exploring the degree of correlation between MT in benthic invertebrates and metal contamination both in the field and in the lab. First, MT concentrations in a small, ubiquitous thyasirid clam, Axinopsida serricata, are being analyzed and compared with metal concentrations (Cd, Cu, Pb, and Zn) found in sediments to determine the benthic response to metal stress in situ. Seven stations were sampled, five in Commencement Bay, an industrialized waterway, and two control sites near the less impacted Nisqually River delta. In addition, sediments were collected from all stations to be used in a lab validation study using purchased polychaete worms, Alitta virens (formerly Nereis virens), which will be exposed to metals in the sediments in order to determine how the proteins develop over a specific time period in a controlled environment. Both A. serricata and A. virens will be analyzed for MT concentrations using a published spectrophotometric method. Results are pending, although preliminary results indicate that there is a detectable amount of MT in both species.
McKenzie, C.M.1*, Hessing-Lewis, M.2,3, Salomon, A.K.2,3
HERRING ROE AS A SPATIO-TEMPORAL DIETARY SUBSIDY IN ROCKFISH
1- University of Alberta, 2 Simon Fraser University, 3- Hakai Network
Pacific herring (Clupea pallasi) are low trophic level fish whose spring spawning events represent a major nutrient and biomass transfer from ocean ecosystems to nearshore habitats. To better understand the food web interactions surrounding herring spawn events, we looked at changes in rockfish (Sebastes maliger and caurinus) diet composition pre and post herring spawn events at a study site in Spiller Channel on the Central Coast of British Columbia. Stomachs were removed from the rockfish, and the contents identified and classified. Herring roe is a substantial dietary subsidy at spawn sites, with rockfish switching from fish to roe. The dietary switch to herring roe peaked at two to three weeks post spawn. This dietary change is most pronounced in females, in which roe accounted for an average of 29% of stomach contents through the month following a spawn event. This may be due to differences in energy requirements for gravid females. To assess how rockfish assimilate herring nutrients, we will perform stable isotope analysis on rockfish tissues. The spatial extent of herring spawns has decreased drastically in the last 70 years. Determining the wider implications of spawn nutrient subsidies is integral to understanding the ecological consequences of herring spawn declines.
Meagher, K.*, Gabara, S., Steller, D., Geller, J.
RHODOLITH ASSOCIATED CRYPTOFAUNA OF CATALINA ISLAND (SOUTHERN CALIFORNIA)
Moss Landing Marine Laboratories
Rhodoliths are free-living calcified red algae (Rhodophyta, Corallinaceae) that create complex three-dimensional habitat supporting rich assemblages of invertebrates. Rhodolith beds are globally distributed with seven beds recently documented around Catalina Island. This study aims to estimate the diversity and abundance of invertebrates in Catalina Island rhodolith beds and compare these parameters between intact rhodoliths, crushed rhodolith sand, and non-rhodolith sand habitat, determine the dominant taxa within the cryptofauna, and ascertain if there is temporal variability in the abundance of the dominant species. Samples were collected on SCUBA using 7 cm diameter cores from the rhodolith beds around Catalina Island. All invertebrates were identified to the lowest taxonomic level possible. The mean abundance varied between substrates but species richness (#spp/core) was very similar between the habitats. The most abundant phylum was Mollusca, which constituted 54.81% of the species with one species, Amphithalanus sp., being responsible for 33.46% of the total abundance. Amphithalanus sp. varied over time but a larger sample size is needed to determine if the variability within the bed is seasonal or spatial. These preliminary findings suggest that Catalina rhodoliths support a diverse cyptofaunal community varying from dominant non-carbonate substrates and from the communities seen in other rhodolith beds.
Meyers-Cherry, N.L.*, Nakamura, R., Wendt, D.E.
ASSESSING LIFE HISTORY TRAITS AND REPRODUCTIVE MPA EFFECTS ON GOPHER ROCKFISH (SEBASTES CARNATUS) IN CENTRAL CALIFORNIA
California Polytechnic State University, San Luis Obispo
Understanding key life history characteristics and genetic relatedness between populations is necessary to determine appropriate management for marine resources. Gopher Rockfish, Sebastes carnatus, comprise 50% of the estimated shallow nearshore rockfish catch in California, yet insufficient data exists concerning the heterogeneity between northern, central, and southern populations. Better life history data will provide information useful for determining uniqueness of central California populations. Over time, fishing efforts that target larger individuals can alter the size structure of populations. Reproductive compensation may result, leading to smaller and younger individuals reaching reproductive maturity at a faster rate while reducing overall fecundity. Marine protected areas (MPAs), established in 2007, may offset reproductive effects. This study addresses the following: 1) What is the size and age at reproductive maturity for Gopher Rockfish? 2) Are the reproductive characteristics of Gopher Rockfish in central California unique? 3) Has fishing pressure caused reproductive compensation and reduced reproductive potential and, if so, do MPAs show signs of negating these effects? Current MPA monitoring projects are being used to collect appropriate data and field samples to address these questions. Field samples of gonads and otoliths are being analyzed in the laboratory to determine relative fecundity and age and growth data.
Meza, E.B1*, Paquin A.L.2, Nielsen, K.J.1
SURFZONE PHYTOPLANKTON AND THE SPRING TRANSITION
1 Sonoma State University, 2 Farallon Institute
In northern California upwelling dynamics define the seasonality of marine ecosystems. Phytoplankton production on the shelf is driven by the cumulative amount of upwelling in a year and the timing of its seasonal transitions. Recent investigations during summer and fall at Bodega Head, CA revealed surfzone phytoplankton are often distinct assemblages compared to those on the shelf, especially during Upwelling Season (April-July) alternating between two characteristic diatom-dominated assemblages. A striking seasonal shift in assemblage structure also occurs at the transition from Upwelling to Relaxation Season (July-September) when dinoflagellates become common. We extend this work to examine the assemblage of surfzone phytoplankton across the transition from Storm Season (December-February) to Upwelling Season. We collected samples twice weekly from the shore, quantifying abundances using the Utermhl method and combined these data with physical data from nearby ocean observing systems. Phytoplankton were evenly distributed among functional groups, but abundance was low and pennate diatoms more abundant during Storm Season. There was a striking transition between Storm and Upwelling seasons associated with changes in physical conditions. Understanding the phenology of phytoplankton assemblages is critical for understanding their influence on nearshore food webs, the genesis of harmful algal blooms and the impacts of climatic change.
Miller, R.J.1*, Page, H.M.1, Brzezinski, M.A. 1,2
13C AND 15N OF PARTICULATE ORGANIC MATTER IN THE SANTA BARBARA CHANNEL: DRIVERS AND IMPLICATIONS FOR TROPHIC INFERENCE
1 Marine Science Institute, University of California Santa Barbara, 2 Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara
We investigated the extent to which temporal variation in the stable isotope composition of suspended particulate organic matter (POM) was explained by phytoplankton biomass and production at a southern California kelp forest and further offshore in the Santa Barbara Channel. On the reef, 13CPOM values were positively correlated with chlorophyll a concentration and phytoplankton productivity. These relationships were weaker offshore, where variation in 13CPOM was better explained by the abundance of dinoflagellates. Reef 13CPOM values were 13C-enriched relative to values offshore. We used the relationship between chlorophyll a and reef 13CPOM to estimate phytoplankton d13C and the contribution of terrestrial C to coastal POC immediately following a rain event. These calculated terrestrial contributions explained 88% of the variability in freshwater runoff. 15NPOM values varied across the year in association with changes in dissolved inorganic N nutrient pools. These results show that trophic studies of coastal marine ecosystems, at least off Santa Barbara, can use inshore POM stable isotope values to represent phytoplankton when freshwater runoff is low. Coastal food web studies, particularly those examining kelp contributions, have typically used offshore POM isotope values to represent inshore phytoplankton. Our results show this assumption may bias results of food web mixing models.
Moore, S.W.1*, Wheat, C.G.2,3, Ambrose, J.D.1, McClure, J.C.1, Paul, C.3, Fournier, T.F. 3
HOME-BREW ROVS: VIABLE PLATFORMS FOR CITIZEN-BASED MARINE SCIENCE?
1 California State University Monterey Bay, 2 University of Alaska, Fairbanks, 3 Monterey Bay Aquarium Research Institute.
Inexpensive, underwater, remotely operated vehicles (ROVs) built by hobbyists and school groups using readily available materials (e.g., PVC pipe, bilge pump motors, speaker wire) have become popular platforms for science, technology, engineering, and math (STEM) education at the K-12 and college/university levels. Although most of these simple designs are limited to shallow use in fresh water, modest upgrades (<$1000 US) to cameras and control systems can produce reliable, precisely maneuverable ROVs capable of recording HD video in marine habitats to depths of at least 10 m. We have been investigating the use of these intermediate-level, do-it-yourself (DIY) ROVs as platforms for appropriately designed citizen science research projects. For example, 6th-8th graders can use these ROVs to conduct periodic video transects of marine life growing on wharf pilings. By reviewing two years worth of previously recorded video images obtained by school children using these ROVs at a harbor pier in Monterey, California, we have been able to monitor seasonal changes in the abundance and distribution of dominant cover species and to detect the arrival and spread of invasive species.
Moye, J.1*, Kline D.E.1, Lindholm J.B.1, Rosen D.2, Cramer A.1, Denney C.1, Kelley H.1, Loiacono S.1, Alfasso A.1, Downey B.N. 1, Fredle M.1, Ramsay E.1, Turner C.1
DISTRIBUTION AND HABITAT ASSOCIATIONS OF KELP GREENLING (HEXAGRAMMOS DECAGRAMMUS) WITHIN THE NORTH CENTRAL COAST REGION OF CALIFORNIA
1 California State University Monterey Bay, 2-Marine Applied Research and Exploration
The distribution of marine fish assemblages is broadly correlated with water temperature and depth. Within this classification, various demersal fishes are known to associate with specific substrate types such as rocky reef or unconsolidated sediments. However, information on fine-scale habitat associations, the scale at which individual fish interact with the seafloor, continues to be limited. In this study, data on the distribution of kelp greenling (Hexagrammos decagrammus) were extracted from videographic and still photographic imagery collected by a remotely operated vehicle as part of the baseline characterization of the new California marine protected areas (MPAs) in the Marine Life Protection Acts North Central Coast study region. The behavior and micro-habitat association of 757 individual fish was quantified, and the geo-referenced position was plotted over high-resolution (2 m) topographic maps of the seafloor within and adjacent to five MPA locations. Preliminary results suggest that kelp greenling associate with rocky, low-relief habitat, possibly with gender and fish length mediating the distribution of this exploited species. Ultimately, the information provided by this study will advance our understanding of kelp greenling in support of current and future efforts for spatial management.
Nedelcheva, R.N.*, Scianni, C.K., Dobroski, N.A., Brown, C.W., Newsom, A.J., Falkner, M.
EXTENDED LAYUPS OF COMMERCIAL VESSELS OPERATING IN SAN FRANCISCO BAY: IMPLICATIONS FOR VESSEL BIOFOULING AND SPECIES INTRODUCTIONS
Marine Invasive Species Program, California State Lands Commission
Fouling of aquatic organisms on the submerged surfaces of vessels can be a potent vector for the introduction of nonindigenous species into new areas. Vessel biofouling has been implicated as a vector in up to 60% of the introductions into California. Additionally, about 65% of Californias established nonindigenous species were first documented to occur in San Francisco Bay (SFB).
It is believed that the longer and more frequently a ship remains in one area, the more likely it is to accumulate biofouling organisms on its submerged surfaces. Unfortunately, reports of commercial ships being anchored and laid up across the world have increased over the past few years – one side effect of the recent world economic downturn. Since 2008, the California State Lands Commission has been collecting information on the hull husbandry practices and fouling-related voyage characteristics of the commercial fleet operating in California. Analysis of the data collected for vessels operating in SFB suggests sharp increases in both the frequency and length of extended layups from 2008 to 2011. Patterns in the frequency and duration of vessel stationary periods will be presented, along with an evaluation of the geographic locations where layups are occurring and implications for species introductions.
Nelson, M.L.*, Latker, A.K., Stebbins, T.D., Velarde, R.G.
LONG-TERM ASSESSMENT OF TRAWL-CAUGHT MEGABENTHIC INVERTEBRATE COMMUNITIES OFF SAN DIEGO, CALIFORNIA (1991-2011)
City of San Diego Marine Biology Laboratory
The City of San Diego has conducted trawl surveys of megabenthic invertebrates surrounding the present discharge sites for the Point Loma and South Bay ocean outfalls since 1991 and 1995, respectively. These surveys are generally designed to assess the possible effects of wastewater discharge or other anthropogenic or natural influences on the community structure of these invertebrates. While results for both areas have been analyzed separately before, the data have never been evaluated together. Therefore, the primary objective of this project was to combine these data to attain a broader synoptic understanding of the entire region. To accomplish this we analyzed data collected between 1991-2011 using analyses available in PRIMER (e.g., cluster analysis, ANOSIM, SIMPROF, SIMPER), and summarized various community metrics by significant cluster groups and plots over time. Preliminary results showed no spatial patterns relative to the outfalls, and that the regions differed in terms of dominant or common species. For example, the sea urchin Lytechinus pictus dominated the deeper mostly sandy silt habitats off Point Loma, while the sea star Astropecten verrilli dominated shallower coarser sediments around the SBOO.
Nicol, C.L.*, Smith, D.P., Watson, F.G.R.
EXPLORING PARTICLE DENSITY EFFECTS ON PARTIAL ENTRAINMENT OF STEELHEAD SPAWNING GRAVELS IN A SMALL GRAVEL BED STREAM
California State University, Monterey Bay
A wide range of literature has explored the topic of bedload transport and particle mobility, but nearly all of it has assumed the particle density of granite (2.65 g cm-1). However recent studies in several small streams near Santa Cruz, CA reveal gravel bed streams dominated by relatively less dense mudstone particles (2.10 g cm-1). The low density gravel may have implications for potential steelhead spawning success and related watershed resource management activities. We developed an experimental study in Yellowbank Creek to monitor density effects on particle entrainment using tagged granite and mudstone particles. Using a logistic regression model, we predict the probability of particle entrainment as a function of particle density, particle size, hiding factor, boundary shear, critical shear and dimensionless critical shear. The model was calibrated using data from the entrainment experiments, field surveys, gage data, hydraulic modeling, and published parameters. Results indicate density, shear stress, particle size, and hiding factor are all important parameters for predicting partial entrainment. The model will be used to predict the impact of low density particles on steelhead spawning potential by analyzing size classes most commonly used in steelhead red construction in central California.
Olson, A.M.*, Trebilco, R., Salomon, A.K.
DO MARINE PROTECTED AREAS ALTER ISOTOPIC NICHE WIDTHS?
Simon Fraser University
Marine protected areas (MPAs) are implemented to conserve community dynamics and biodiversity by protecting populations from human activities such as over-fishing and habitat destruction. While the effects of MPAs can be measured directly from abundance and spillover observations, our understanding of how they affect food web dynamics and the ecological niches of species is limited. In our study, we compared niche widths of rockfish from sites within a Rockfish Conservation Area and in areas of no protection in Haida Gwaii, British Columbia, Canada. Stable isotope analysis was conducted on rockfish muscle tissue to determine 13C and 15N signatures. Using Bayesian inference, we calculated multivariate isotopic niche space as a means of quantifying the ecological niche. We compared isotopic niche widths of different rockfish species within each area using standard ellipse areas to understand intra-area dynamics. We also compared the niche widths of overall rockfish communities between areas with and without protection to observe inter-area variation. Our results show no significant evidence of intra-area differences of niche widths between species. However, comparing among areas, trophic diversity appears to be greater in the rockfish community with protection compared to areas without protection.
Paradise, A.P.*, McCarthy, D.A.
THE ABUNDANCE AND DISTRIBUTION OF THE BLENNY SCARTELLA CRISTATA ALONG AN INTERTIDAL SABELLARIID HARDBOTTOM HABITAT IN FLORIDA
Shelter availability and quality can shape distribution and abundance of many crevice dwelling fish. Research investigating the role of these factors has focused on fish associated with coral reefs as opposed to other marine habitats. Along the Florida coast, the blenny Scartella cristata is common in intertidal and shallow subtidal hard bottom habitats with considerable coverage of the shelter-enhancing sabellariidPhragmatopoma lapidosa. The effect of this shelter enhancement on S. cristata is unknown. In this preliminary study, we used field surveys to compare the abundance and size of S. cristata on the inshore and offshore edge of a shallow water hardbottom in southeast Florida. We measured the quantity and quality of shelters created by sabellariids, limestone solution holes and empty barnacles. Total lengths ofS. cristata on the inshore edge of the natural reef were significantly higher than those found on the offshore edge (t = 3.163, P = 0.034). S. cristata abundance generally increased on the inshore edge though not significantly so (t = 2.668, P = 0.056). Inshore, higher percentage covers of P. lapidosa afforded higher abundances and size ranges of shelters. Locally, P. lapidosa may considerably affect the abundance of this and other crevice dwelling species.
Parker, H.C..1*; Becker, B.J.1; Vadopolis, B.2; Allen, B.3; Behrens, M.D.4
OLYMPIA OYSTER LARVAL DISTRIBUTION IN A SMALL RESTORED BAY IN PUGET SOUND: A PILOT STUDY USING PASSIVE TUBE TRAPS AND QPCR
1 University of Washington Tacoma, 2 – University of Washington School of Aquatic and Fishery Sciences, 3 Puget Sound Restoration Fund, 4 Pacific Lutheran University
The Olympia oyster (Ostrea lurida) is the subject of many restoration projects in the Pacific Northwest. One method of assessing the efficacy of such projects and the health of the O. lurida population is in sitularval counts during breeding seasons, but sorting and identifying larvae is resource intensive, limiting the practicality of this method. The purpose of this experiment was to use time-integrating larval tube traps with quantitative polymerase chain reaction (qPCR) to determine the applicability of using these methods in conjunction as a novel approach to larval surveys. Fidalgo Bay, a site with a restored population of O. lurida, was chosen for the pilot, and six traps were deployed for one week with additional traps deployed the following week in the same locations. Samples were filtered, prepared, and analyzed using the qPCR method. Inhibition of qPCR occurred in some standards and samples due to complications of using qPCR with field-collected samples. Preliminary results derived from samples without inhibition indicate larvae in approximate quantities realistic to the scope of this study. With minor modifications to the procedure, these methods have the potential to simplify and make feasible larval surveys that could otherwise be considered too impractical to undertake.
Paterson, C.N.*, Allen, L.G.
THE GENETIC DIVERSITY AND POPULATION STRUCTURE OF BARRED SAND BASS, PARALABRAX NEBULIFER, IN SOUTHERN CALIFORNIA
California State University, Northridge
The barred sand bass, Paralabrax nebulifer, is a common recreational species off the coast of southern California. They range from Santa Cruz, CA to the southern tip of the Baja peninsula in Mexico. Barred sand bass and their sister species (P. clathratus and P. maculatofasciatus) comprise one of the largest recreational fisheries in Southern California. Barred sand bass are aggregate spawners which makes them susceptible to overfishing. Recently populations of barred sand bass have experienced a decline in numbers and subsequently the fishery has collapsed. Currently, nothing is known about the genetics of bared sand bass. This study uses the mitochondrial DNA control region to determine the genetic variation and population structure of barred sand bass populations in Southern California.
STRESS AND GEOMORPHOLOGY: A QUANTITATIVE ANALYSIS OF COMMUNITY STRUCTURE IN THE ROCKY INTERTIDAL USING TERRESTRIAL LASER SCANNING
Moss Landing Marine Laboratories
Conspicuous patterns of ecological stratification are ubiquitous within rocky intertidal ecosystems. Current literature primarily attributes physical and biological stressors as chief drivers of community structure in these habitats. It has been suggested that substrate geomorphology may also hold significant influence in shaping the distribution and abundances of organisms living here, yet few studies offer robust scientific evidence to support this theory. This study investigated how geomorphologic properties modify community structure by exacerbating or ameliorating various environmental stress mechanisms. A novel methodological approach combined cutting-edge terrestrial laser scanning (TLS) technology with traditional ecologic surveying. These methods were designed to quantitatively examine whether rugosity, surface aspect and/or complexity of the substrate within mid-upper rocky intertidal zones correlated with patterns in species diversities and abundances of inhabitant biota. I hypothesized that higher cover, biomass, and species diversity of invertebrate rocky intertidal communities were associated with substrate containing characteristics expected to lower desiccation stresses. Results of data collection at three different sites around the Monterey Bay region from two study seasons were reported.
Perales, B.1*, Whitcomb, A.2, OMalley K.2
AN EVALUATION OF COHO SALMON (ONCORHYNCHUS KISUTCH) JACK MATE CHOICE BASED ON IMMUNE-RELEVANT GENES
1 California State University Monterey Bay, 2 Oregon State University, Hatfield Marine Science Center
It has been recently shown that when hatchery reared coho salmon spawn in the wild they have a lower reproductive success (RS) compared to wild fish. This decrease in RS may be driven by mate choice. In the wild, females select favorable males to mate with, but in the hatchery choice has been eliminated. However, hatchery coho jacks, small sexually mature 2 year old males do, not experience the same fitness decline as 3 year old males. Coho jacks employ a sneaker strategy suggesting they mate opportunistically. We therefore predict that jacks would not exhibit a mate choice. We tested for non-random mating by comparing observed mate pairs with randomly generated pairs and found significant evidence for non-random mating at four immune-relevant gene linked markers. Immune-relevant genes can be used to test for mate choice because they can offer genetic benefits to offspring. However, we found no evidence for a preference type; genetically similar or dissimilar. Interestingly, we found a positive correlation between the greater number of shared alleles between mate pairs and increased RS at three of the markers. Our results suggest that some of the immune-relevant markers influence the RS of wild spawning coho mate pairs.
Pernet, B.1,*, Valentich-Scott, P.2
WHO’S ON WATTS (TOWERS): THE MOLLUSCAN FAUNA OF A NATIONAL HISTORIC LANDMARK
1 California State University Long Beach, 2 Santa Barbara Museum of Natural History
Watts Towers (WT) is an assemblage of 17 structures including seven towers, ranging in height 11-99 feet built by Italian immigrant Sabato Rodia between 1921-1954. They were built of a frame of scrap metal, which was wrapped with wire mesh and coated with mortar. Rodia embedded found objects e.g., fragments of bottles and tiles into the wet mortar. Among these objects are tens of thousands of mollusc shells. Art conservationists and historians know little about the identities or origins of these shells. We surveyed the molluscs of WT, with the aims of providing baseline data for conservationists and making inferences about where Rodia obtained shells. We identified ~33 spp. of molluscs at WT; ten of these are gastropods, and the rest bivalves. Bivalves in the genus Chione are numerically dominant. Almost all of the species present are native to southern California, and the shells of only one established non-indigenous species, Crassostrea gigas, occur there. Shell condition suggests that most local shells were collected post-mortem, probably as beach drift. WT was adjacent to a stop on the now defunct “Red Car” public transit system, on a line that led directly to Long Beach and San Pedro; most of the shells of WT were likely collected in that area.
Pritchard, C.E.*, Rimler, R., Shanks, A.L.
LARVAL DISPERSAL OF THE OLYMPIA OYSTER, OSTREA LURIDA, IN THE COOS BAY ESTUARY
Oregon Institute of Marine Biology, University of Oregon
Ostrea lurida is the only native oyster on the Pacific Coast of the United States. Found in intertidal and shallow subtidal estuarine environments, its populations have been in decline over the last century due to overharvesting, massive die-offs, habitat loss and pollution. Long considered a delectable treat with a very distinct taste, this oyster currently has both commercial and recreational bans on its harvest, and restoration efforts have become a priority in recent years in order to promote recovery of natural populations. To determine the best sites at which to focus restoration and produce sustainable populations of O. lurida in the Coos Bay estuary, we are attempting to define the distribution of larvae and settlers in the bay. We have placed larval traps and settlement plates around the bay, and continue to monitor these throughout the breeding (July-October) and settlement season (July-December). To date, our data indicate that larvae and settlers are most prevalent in the upper reaches of the bay, and almost non-existent in the waters near the mouth of the bay. We hypothesize that this pattern is a result of the hydrodynamics of the bay, limiting larval supply to the more marine areas, and work with drogues supports this mechanism as a major driver of larval distribution.
ECOSYSTEM SERVICES IN SEAGRASS BEDS: INVERTEBRATE ASSEMBLAGES WITH VARYING COMBINATIONS OF TERRESTRIAL AND MARINE PROTECTION
University of California, Santa Cruz
Tropical countries are facing the challenge of providing for their growing coastal populations. In the Philippines, people on the 7,100 islands rely on coastal fisheries for food. Seagrasses are critical components of coastal ecosystems because they are nursery grounds and habitat for fisheries (Orth et al., 2006). My study aims to assess the ecosystem services from terrestrial protection and nearshore marine protection by studying macroinvertebrates of human importance in seagrass beds. Between August-September (2010) and May-August (2011). I conducted macroinvertebrate swims in seagrass beds around seventeen islands under four categories of terrestrial and marine protection: terrestrial protection and marine protection, terrestrial protection and marine unprotected, terrestrial unprotected and marine protected, and terrestrial unprotected and marine unprotected. I defined terrestrial protection as lands without human habitation and development, or when possible, lands with formal terrestrial protection status. I defined marine protection as marine reserves or no-take zones that are officially designated by the local government. In each site, I counted and identified invertebrates along two 50m transects, one along a deep transect line, 1 along a shallow transect line. Using CLUSTER analysis, with the program PRIMER, I found differences in the macroinvertebrate assemblages among categories of protection.
Raymond, W.W.*, Duggins, D.O., Dethier, M.N.
BETTER WITH AGE? URCHIN GONAD INDICES ON DIETS OF FRESH AND AGED KELP
Friday Harbor Laboratories
When kelps in nearshore temperate marine ecosystems detach from the substrate, their substantial biomass is transported into other habitats, providing a carbon subsidy to consumers. Following detachment, drift kelps gradually degrade, but the effect of kelp degradation, or aging, on nutritional value to consumers is not well understood. In the San Juan Islands, Washington, red sea urchins,Strongylocentrotus franciscanus, are an abundant consumer of drift kelp in both shallow and deep water. Previous studies have tested the gonad production of urchins fed different fresh algae diets. However, wild urchins below the photic zone commonly capture and eat aging drift algae. We are investigating the effect of fresh and aged kelp diets on the gonad index of red sea urchins over an 18 week feeding trial. Analysis of gonad index even after 9 weeks indicates a significant effect of algal species but not age. Urchins fed fresh or aged Nereocystis luetkeana had significantly higher gonad indices than urchins fed fresh or aged Agarum fimbriatum. These results suggest that algal nutrition for urchins may not be limited by aging and therefore depth. We plan to incorporate fatty acid data from urchin gonads to further investigate these issues.
Reichert, A.N.*, Garza, C., Toews, S.
ANALYZING THE AGE DISTRIBUTION OF BLACK SURFPERCH (EMBIOTOCA JACKSONI) RELATIVE TO HABITAT STRUCTURE AND COMPOSITION
Science and Environmental Policy, California State University, Monterey Bay
Characterizing fish species by habitat type is a useful strategy in the designation of marine protected areas (MPAs). In this study we examined if there is a relationship between different age classes of E. jacksoni and subtidal habitat structure and composition. Our approach is to use the locations, habitat data, and fish age to produce a predictive habitat model. Fish were obtained from 4 locations in the Monterey Peninsula. Age was determined by counting concentric growth rings of otoliths. GIS landscape analysis and spatial statistics were employed to test and model the association of fish location and age with the habitat parameters derived from bathymetric data. This information may hold value in future monitoring of the life cycles of black surfperch and other ecologically vulnerable species.
Rice, M.R.1*, Langdon, C.2
EFFECTS OF OCEAN ACIDIFICATION ON MESOCOSM CORAL CALCIFICATION RATES
1 Sonoma State University, Department of Biology, 2 University of Miami Rosenstiel School of Marine & Atmospheric Science
Ocean Acidification refers to the increasing uptake of anthropogenic CO2 by the ocean resulting in the decline of pH level. Elevated levels of pCO2 are altering the carbonate chemistry of the ocean, lowering the amount of CO32- available to corals for calcification. This impacts hermatypic corals, which play a significant role in the structure and biodiversity of coral reefs. In this study, the effects of projected pCO2levels for the end-of-the-century (1000 ppm) on the calcification rates of coral reef species were determined. It was hypothesized that elevated pCO2 levels would cause a decrease in coral calcification rates due to its effect on CO32- concentration. Water samples were collected at the start and end of one-hour incubations and dissolved inorganic carbon analyses and total alkalinity titrations were performed. These data were used to calculate the aragonite saturation state (ar) of the water and calcification rate. The relationship between average calcification rates and elevated pCO2 was not statistically significant (P=0.068). However, a trend is evident because elevated pCO2 conditions resulted in decreased average calcification rates, giving support to the hypothesis that increased pCO2 levels inhibit skeletal growth. A strong correlation was present between increased pCO2 and decreased ar.
Rimler, R.N., Pritchard, C.
LARVAL SETTLEMENT AND POST-SETTLEMENT MORTALITY AS DETERMINANTS OF THE SPATIAL DISTRIBUTION OF OLYMPIA OYSTERS IN COOS BAY, OR
University of Oregon
The population of Olympia oysters (Ostrea lurida) in Coos Bay is patchy and restricted to the mesohaline portion of the estuary. There are probably several factors responsible for this distribution, including larval supply, settlement preferences, and post-settlement mortality. How do these processes work together to structure the adult population? To investigate larval supply vs. settlement, we placed larval traps and settlement plates at five sites throughout Coos Bay, and are counting larvae collected from the water column and settlers present on the plates every two weeks. Ultimately, we will determine the proportion of larvae in the water to settlers on the plates, and track how that relationship might change over time and with location. To determine the influence of post-settlement mortality, I plan to track the growth of juvenile oysters at these same sites. We hope that our results will help to inform projects intent on revitalizing this struggling native species.
Rose, H.S. 1, Schmidt, K.2, Marriffini, M.2
VALIDATING THE USE OF MORPHOLOGICAL CHARACTERISTICS OF TWO CLOSELY RELATED ROCKFISHES USING GENETIC TECHNIQUES
1 – California State University Monterey Bay, 2 – Moss Landing Marine Laboratories
In a current Masters thesis separating the life history of two closely related rockfishes, the Blue Rockfish,Sebastes mystinus and its undescribed counterpart, Sebastes mystinus sp., morphological characteristics were used to classify the individuals into species groups. The objective of this study was to determine the accuracy of categorization based on external morphology when differentiating the Sebastes mystinus spp. I used molecular techniques to analyze DNA in 60 samples that had been assigned a species. I predict that genetic results will show that a significant portion of the fish were correctly identified to species, which will therefore validate the use of the morphological characteristics in assigning proper species between these groups, as well as providing useful data that will aid in the taxonomic separation these species in the near future.
San Miguel, R.A.1,2,4*, Wilde, S.3, Dunn, R.R.4
MAPPING THE POTENTIAL SPREAD OF AVIAN VACUOLAR MYELINOPATHY IN THE UNITED STATES
1 – Moss Landing Marine Laboratories, 2 California State University: Monterey Bay, 3 University of Georgia, 4 North Carolina State University
Avian Vacuolar Myelinopathy (AVM) is the number one cause of unknown bald eagle deaths in history. Thus far, the disease has been isolated to the south eastern United States. It has been linked to a new species of cyanobacteria within the order Stigonematales, which lives as an epiphyte on the invasive aquatic plant, Hydrilla. Waterfowl feed on Hydrilla ingesting the alga, which is believed to release a neurotoxin that forms lesions in the brains of the waterfowl, which are in turn consumed by birds of prey like bald eagles. The southeastern United States already has a relatively small bald eagle population making AVM a very large threat to its survival. Because AVM has proven to be relatively isolated thus far, we created a map to demonstrate where the disease could potentially spread depending on the presence of Hydrilla, bird banding data of the American coot (Fulica americana), and where the newly identified cyanobacterium already exists. Our results showed that, while Hydrilla seems to be most concentrated in the southeastern United States, American coots migrate all over the United States with no visible patterns potentially facilitating the spread of this epiphytic alga and AVM across the United States.
Sato, K.*, Grupe, B., Takeshita, Y., Nam, S., Navarro, M., Pasulka, A., Maloney, J., Ballard, J., Gallagher, K., Levin, L., Frieder, C.
THE SAN DIEGO COASTAL EXPEDITION: A STUDENT-LED EXPLORATION OF LOCAL SEEPS AND LOW OXYGEN/LOW pH ECOSYSTEMS
Scripps Institution of Oceanography, UC San Diego
As our oceans become more acidic, warmer, and increasingly deoxygenated, it is critical that the next generation of scientists understand these environmental changes, their natural variability, and their effects on marine ecosystems and ecosystem services. The San Diego Coastal Expedition is a multidisciplinary, student-led research cruise emphasizing graduate student projects that seek to expand our knowledge of local continental margin ecosystems. Through the use of various geophysical, oceanographic, and ecological techniques, this two-part research cruise (July and December 2012) aims to (1) assess benthic and pelagic community responses to strong gradients of dissolved oxygen and carbon dioxide and (2) search for cold seep ecosystems. Here we characterize the extent of the Oxygen Minimum Zone and its interaction with seafloor fauna by exploring depth gradients in oxygen, pCO2, pH, and CaCO3saturation states. We present evidence of a methane seep discovery and assess trophic structure and relative abundances of soft sediment faunal communities across various depths. We shared photos and blogs via various social media, which allowed us to communicate our science to over 15,000 people worldwide. In December 2012, we will resample stations and seep sites with a 10-day cruise and continue our outreach efforts through our website: http://bit.ly/sdcoastex
Schiebelhut, L.M.*, Abboud, S.S., Gomez-Daglio, L., Swift, H.F.
QUICK, CLEAN AND CHEAP: COMPARING DNA EXTRACTION METHODS FOR DIVERSE MARINE TAXA
University of California Merced
As population genetic and phylogenetic studies expand to include next generation sequencing technologies, a DNA extraction method that balances time and cost without compromising DNA quality is necessary. The commonplace CTAB phenol/chloroform extraction has been necessary to obtain long-term PCR-quality DNA, but creates a methodological bottleneck. We tested eight extraction methods, ranging from low- to high-throughput, on eight marine phyla (Porifera, Cnidaria, Annelida, Arthropoda, Mollusca, Echinodermata, Chordata, and Ochrophyta). We assessed extraction efficiency, DNA quality, and affordability of each method. Extraction efficiency was measured as (1) the extracted DNA concentration per microgram of sample and (2) reliability of PCR amplification of two molecular markers (COI and histone 3). DNA quality was visually assessed using gel electrophoresis and quantified using NanoDrop absorbance ratios. Affordability was estimated in terms of time and material expense. Preliminary analyses show clear differences in DNA quality and PCR success between extraction methods. The best performing methods include (1) the low-throughput CTAB phenol/chloroform extraction, one of the most affordable methods in terms of material expense, but also most time-consuming, and (2) the higher-throughput AcroPrep PALL glass fiber plate extraction, which is the most cost effective and one of the most time-efficient of all methods.
Schoenrock, K.S.1*, J.B. Schram1, C.D. Amsler1, J.B. McClintock1, M.O. Amsler1, Angus, R.A.
Climate change impacts on the physiology of calcifying and non-calcifying encrusting Antarctic macroalgae along the western Antarctic Peninsula NEED THIS ONE
1- University of Alabama at Birmingham
The past centuries anthropogenic emissions have increased the amount of CO2 absorbed into the worlds oceans, altering the balance of carbonate species. Currently, climate change projections predict a decline in pH from todays average level of 8.1 to 7.7 by 2100, which will coincide with increased atmospheric and oceanic temperatures. Crustose coralline algae (CCA) are widespread and ecologically important calcified members of the marine benthic community and among those organisms predicted to be affected by climate change. Along the western Antarctic Peninsula CCA species are common in the subtidal habitat, especially above 30 m depth where percent cover can reach up to 77% of the benthos. The goal of this project was to investigate responses to reduced seawater pH and rising seawater temperature in common calcified and non-calcified crustose algae. Other studies indicate potential for a shift in ecosystems from calcified to non-calcified marine algae when exposed to climate change conditions. Microcosm experiments were constructed using a 2 x 3 factorial design reflecting current conditions, near-term, and long-term condition predictions for pH and temperature along the WAP. Calcification of thalli, bleaching of thalli, chlorophyll a content, photosynthetic characteristics, and growth of a CCA species and a non-calcified crustose red alga, Hildebrandia lecannellieri, were used to compare physiological responses between treatments. Results may indicate potential for a regime shift between calcified and non-calcified algae in the marine benthos along the WAP.
Schram, M.J.*, Steele, M.A.
the effects of SIMULATED size-selective harvesting on a protogynous temperate reef fish, rhinobogiops nicholsii
California State University, Northridge
Typically, fisheries disproportionately target larger individuals, creating an artificial selection pressure against large sizes and traits that determine size. Correlative studies have established a link between harvesting tactics and changes in life history characteristics of protogynous fishes. We used a field experiment to investigate the impacts of simulated size-selective harvesting on the reproduction and growth of a protogynous fish that is not normally harvested. Artificial reefs were constructed and populated with a standard density and size distribution of blackeye gobies (Rhinogobiops nicholsii). Densities and size-distributions were then manipulated, simulating fishery-style harvesting. Reproductive output and growth were then measured over a period of weeks. We found that size-selective harvesting had no significant effect on the reproductive output or growth of the blackeye goby. This result, however, appeared to be due to unexpectedly high immigration and settlement, which caused population densities and size structures to be similar among the simulated harvesting treatments. From these results we infer that relatively low intensity size-selective harvesting may not impact reproductive output or growth of protogynous species.
See, J.S. *, Lowe, C.G.
DISC SHAPE AND CAUDAL SPINE PLACEMENT CORRELATES TO DOMINANT SWIMMING MODE IN STINGRAYS-IMPLICATIONS FOR DEFENSIVE BEHAVIOR
California State University, Long Beach
Stingrays can be loosely divided into two groups that correspond to body shape and locomotive abilities. Species with higher aspect ratio pectoral fin and central body (discs) and that are more efficient mid-water swimmers tend to have the spine placed closer to the body than those with discs of higher circularity. This variation in caudal spine placement is likely important in how the spine is used for defense along with other behaviors. Morphometric comparisons of disc and tail morphology were made on stingrays (suborder Myliobatoidea), with a focus on species found in the Southern California Bight and Baja California. Species were also categorized as predominantly oscillatory or undulatory swimmers. Species with a more circular disc were found to have the spine placed further back on the tail(r=0.734, p<0.001). Spine placement on tail was correlated to tail thickness and length, with species having the most posteriorly oriented caudal spines having the thickest and shortest tails. Rays with undulatory swimming mode had higher circularity and lower aspect ratio, shorter tails(average 49% versus 65% of total length) and spines placed further away from the body (average 38% of body length versus 29% of body length), and further down the tail(36% of tail length versus 16% of tail length) than oscillatory swimming mode species. Relative spine size for three abundant nearshore species in the Southern California Bight was greatest for Urobatis halleri, the species with the highest disc circularity rating and an undulatory swimmer. These morphological differences have implications for different defensive behavior between the two body forms.
Seubert, E.A.1*, Kwan, C.K.1,2
TRAIT-MEDIATED INDIRECT INTERACTIONS BETWEEN A PREDATORY CRAB AND DIFFERENT POPULATIONS OF THE STRIPED DOGWHELK, NUCELLA OSTRINA
1 Bodega Marine Laboratory, University of California, Davis, 2- San Diego State University
A well-known phenomenon in food webs is the cascading effect of a top predators consumption of a lower prey species, and the direct and indirect interactions that result. Our experiment focused on trait-mediated indirect interactions (TMIIs), where the presence of predatory cues affects traits in the prey species, which subsequently affects that prey species resource. We conducted a laboratory experiment to test the effect of the presence of a crab predator (Cancer productus) on feeding, growth rates, and shell morphology changes of the striped dogwhelk, Nucella ostrina. We also tested if these responses would differ between individuals from two source populations. For two months, we exposed laboratory-reared whelks originating from the open coast and Bodega Harbor to waterborne cues from a predator consuming conspecific snails, just predator cues, and no cues. Dogwhelks not exposed to predatory cues consumed more barnacles and grew more than those exposed to predatory cues, particularly those exposed to predators consuming conspecifics. We found a trend in the data that indicates the origin of the dogwhelks affects their feeding behavior and growth rates. These results indicate that predator presence, depending on prey population, may have varied non-lethal effects on marine food webs.
Silberg, J.N.* , Salomon, A.K.
INVESTIGATING PREDATOR RECOVERY AND NON-LINEAR DYNAMICS IN KELP FOREST FOOD WEBS AND REEF FISH
Simon Fraser University School of Resource and Environmental Management
The cascading affects of predator depletion or recovery are often accompanied by time lags and non-linear dynamics. Forecasting when and where these thresholds lie remains a foundational question in ecology. In temperate marine ecosystems, sea otters (Enhydra lutris) are well known to consume herbivorous invertebrates, releasing macroalgae from grazing pressure and allowing kelp beds to flourish. This transition may be non-linear and exhibit hysteresis, resulting in alternative states. Furthermore, the occurrence and magnitude of these non-linearities appear to be context-dependent, but to date we have little ability to forecast when, where and to what degree these indirect effects will manifest. I propose to quantify the ripple effects of sea otter recovery on temperate reef fish diversity, biomass and isotopic niche space along a documented gradient in sea otter occupation time. I will use a space for time substitution to represent variation in occupation time. Results of this study will help advance ecosystem-based approaches to conservation and will add valuable information for managers to include in future management plans for federally listed rockfish species.
Smolenski, J.R.*, Spindel, N.B., Edmunds, P.J.
IMPLICATIONS OF USING LED LIGHTS TO TEST THE EFFECTS OF OCEAN ACIDIFICATION ON CORAL CALCIFICATION
California State University Northridge
Laboratory investigations of ocean acidification (OA) effects on tropical corals have started using LED lights instead of metal halides. LEDs produce little heat, can adjust for spectral quality and light intensity, and are cost-effective in long-term experiments. Though neither light source simulates solar radiation perfectly, LEDs enhance blue wavelengths more than commonly used metal halides. Therefore interpretation of experiments using LEDs may be difficult. We tested the hypothesis that spectral composition of LEDs has no effect on calcification of the coral Porites rus when subjected to high Pco2. Corals were exposed to ambient (41 Pa) and high (70 Pa) Pco2 under red (645nm), green (530nm), blue (450nm), or white (unfiltered) light adjusted to similar intensities. Results showed a significant interaction of Pco2 and spectral composition, with calcification in high Pco2 elevated by 75% (green) and 32% (blue) when compared to white light. Calcification was also greater in high Pco2 than ambient Pco2 by 96% (green) and 2% (blue). Under red LEDs, corals grew 13% less than corals under white light and 26% less in high Pco2. Spectral composition affects calcification of P. rus when exposed to high Pco2, therefore experiments using blue-enriched LEDs should be interpreted with caution.
Stokes, J.1*, Burnaford, J.L.2 and Nielsen, K.J.1
SPATIAL AND TEMPORAL VARIATION IN SACCHARINA SESSILIS MORPHOTYPES: EVIDENCE SUPPORTING THE ROLE OF BULLAE IN AMELIORATING EMERSION
1 Sonoma State University, 2 California State University, Fullerton
Saccharina sessilis exhibits two morphologies: bullate and strap-like. Researchers have assumed that bullae benefit thalli by increasing turbulent flow and mass transport of nutrients or gases at the thallus surface. However, both morphotypes are found on wave-exposed shores where mass transport is not limiting. We present evidence that bullae serve instead to ameliorate emersion stress. Maximum quantum yield of fluorescence (MQY) declines with thallus water content and emersion time; however field measurements of MQY on low-zone, strap-like thalli declined more than those of bullate high-zone thalli during emersion on a sunny day. At a wave exposed site in northern California, morphotypes varied systematically with tidal height and over time. In late spring, when cumulative daylight emersion times were long, bullate thalli dominated, and strap-like thalli were virtually absent from the upper Saccharinazone. Later in the summer when cumulative daylight emersion times were reduced, strap-like thalli became abundant and dominated the lower Saccharina zone, while bullate thalli remained dominant at the upper edge. In contrast, at a wave protected site in Washington where cumulative daylight summer emersion times are greater, only bullate thalli were observed. The presence of some within thallus variation in blade morphotype suggests this trait is plastic.
Swinford, N.A.*, Wright, W.G., Mason, M.J., Kabala, R.T.
RISK OF DISLODGEMENT DURING TERRITORIAL ENCOUNTERS IN LOTTIA GIGANTEA IS NEGLIGIBLE, SAVE FOR THE YOUNGEST COMBATANTS.
School of Earth and Environmental Sciences, Chapman University
Modern analyses of territorial behavior benefit from knowledge of the risks of particular behavioral choices; risks that are readily measured in the territorial limpet, Lottia gigantea. We here begin such an analysis with field estimates of the risk of dislodgment from the substratum by a territorial resident. We first measured thrust force in territorial limpets over a range of sizes (37-70 mm) in response to a bait limpet, removed from another area and placed in front of territorial residents. We compared this thrust force to measurements of the shear force required to dislodge moving limpets. Thrust force of territorials was significantly correlated (r=0.65; n=27; P=0.0001) with shell length (SL). Resistance to shear force was also correlated with SL (r=0.68, n=63, P<0.0001), but had a much steeper slope (0.79 Newtonsmm-1) than did thrust force (0.12 Newtonsmm-1; t86 = 2.65, P=0.01). The regression of shear-force resistance vs SL rises above the maximum observed thrust-force (6.4 Newtons) at SL = 29 mm, suggesting that only the smallest limpets are at immediate risk for dislodgement by territorials. These observations suggest that the risk of dislodgement from the substratum by an aggressive resident is actually quite low, except for the very youngest intruders.
Talley, D.1,2, Carter, D.1,2, Cazarez D.1, Godinez, C.3, Goodwin, L.1, Islas, I. 1, Razon, L. 1, Rivera, M.1, Tran, G. 1
ALGAE TAKES A HIKE: MARINE RESOURCES SUPPORT ISLAND FOOD WEBS
1 Ocean Discovery Institute, 2 University of San Diego, 3 – Comisin Nacional de reas Naturales Protegidas
The islands of Baha de los ngeles are among the driest habitats on earth, yet they sustain a high density of terrestrial life due to spatial subsidy from the adjacent and highly productive Gulf of California. While previous work has demonstrated the importance of marine inputs to terrestrial food webs, the specific pathways are not well understood. By using a nitrogen isotope (15N) to enrich naturally occurring macroalgae, we can learn more about the various pathways by which marine spatial subsidy is entering, and thus sustaining, island food webs. In the summer of 2012, Sargassum spp. was collected and soaked in an enriched 15N solution for two days, then placed on the shoreline of a small island in the archipelago of Bahia de los Angeles. Terrestrial organisms (arthropods, lizards, and rodents) were sampled at intervals following algal addition along three transects, which extended from the experimental algae to 150 meters inland. Isotopic analysis showed the algae successfully took up the labeled Nitrogen, and quantitative population data showed that there was a higher abundance of organisms found closer to the shoreline, with 31% of organisms collected coming from within 10 meters of the shoreline. In order to better understand the mechanisms in which marine energy is transported inland, we also looked at the distribution and movements of the two native mouse species. The omnivorous species (Peromyscus maniculatus) was more common near shore and was far more mobile compared to the granivorous species (Chaetodipus rudinoris) Results of this research will provide us a better understanding of the trophic connections between these two distinct habitats, ultimately improving our ability to conserve them.
Taylor, J.R.1, A.P. DeVogelaere2, E.J. Burton2, O. Frey2, L. Lundsten1, L. Kuhnz1, P.J. Whaling1, C. Lovera1, K.R. Buck1, J.P. Barry1
DEEP SEA BENTHIC MEGA- AND MACROFAUNAL COMMUNITIES ON AND AROUND A LOST INTERMODAL SHIPPING CONTAINER IN THE MONTEREY BAY MARINE SANCTUARY, CALIFORNIA
1 – Monterey Bay Aquarium Research Institute, 2 – Monterey Bay National Marine Sanctuary, NOAA
An estimated 10,000 intermodal containers are lost at sea yearly along international shipping routes. Carrying an assortment of cargo, and covered with paint of varying toxicity, lost containers can take centuries to degrade. During a storm in Feb 2004, 24 standard steel intermodal containers fell off Chinese Merchant Vessel M/V Med Taipei along Californias central coast. MBARI scientists discovered one of these containers at 1281m depth in Monterey Bay National Marine Sanctuary, in June 2004. To assess ecological condition of the site, it was revisited during a March 2011 research cruise in collaboration with the Monterey Bay National Marine Sanctuary (MBNMS). During this revisit, sediment core samples and high-definition video transects were taken up to 500m from the container. Results show the appearance of this container has caused changes in megafauna communities up to 50m away, with reduced megafauna biodiversity 1m from the container. Community compositions are distinct between the containers hard substrate, sediment within 1m of its base, and benthos >1m from its base. Mega- and macrofaunal communities 1m were skewed towards higher densities of fewer fast-growing, short-lived species.
Tobosa L.R.1, Wendt D.2, Waltz G.2, Walker J.2, and Starr, R.M.3
A COMPARISON OF ROCKFISH SPECIES DIVERSITY INSIDE AND OUTSIDE MPAS ALONG A LATITUDINAL GRADIENT ON THE CENTRAL CALIFORNIA COAST
1 California State University Monterey Bay, 2 California Polytechnic University San Luis Obispo, 3 Moss Landing Marine Laboratories
Sebastes spp. richness is greatest along the latitudes of 33-37 N, which corresponds with four of Californias new marine protected areas (MPAs) established in 2007 (Ao Nuevo, Point Lobos, Piedras Blancas, and Point Buchon). It has been suggested that Sebastes spp. richness decreases along a north-south latitudinal gradient and that MPAs increase diversity relative to non-protected areas (REF). The California Collaborative Fisheries Research Program (CCFRP) has been monitoring MPAs along the central California coast with standardized hook-and-line methods since 2007. With five years of data (2007-2011), I used the Shannon-Wiener diversity index (H) to investigate whether Sebastes spp. diversity followed a latitudinal gradient and if there exists a difference in diversity between protected and non-protected areas. There were significant differences found between MPA and REF sites; and theres an indication that the southernmost area had significantly less Sebastes spp. diversity compared to the other three northern areas. The results from my analysis can be used by the state of California in its ongoing adaptive management of marine protected areas and in stock assessments of nearshore fish species.
Triebnig, C.J.1*, Takagi, K.K. 2, Wright, W.G. 1
HERMIT CRABS AVOID PREDATOR CUES, REGARDLESS OF THE STRENGTH OF THEIR PROTECTIVE SHELLS
1 – Chapman University, 2 University of Georgia
Evolutionary theory and empirical observation have established that behavior of prey species is sensitive to predator cues. An extension of this idea asserts that more vulnerable individuals should have an increased sensitivity to predator cues. We tested this sensitivity by measuring predator avoidance and food consumption in individual hermit crabs, Pagurus samuelis, forced into either weakened (decalcified) or natural shells. Using a simple Y-maze, we found that crabs significantly avoided (78.3% 5.5%; N = 12; one-sample t-test vs. H0 = 50%, t = 5.15, P = 0.0005) chemical cues from a predatory crab, Cancer productus. Hermit crabs transferred to experimentally weakened shells also avoided predator cues (76.0% 7.8%; N= 10, P = 0.0009); however, they did not do so significantly more (two-sample t-test, N = 10, 10; NS) than crabs transferred to untreated, control shells (74.0% 6.0; N= 10; P =0.0002). Finally, hermit crabs exposed to predator cues consumed standardized squid pellets at half the rate of control crabs exposed to no predator cues (N = 8,8; two-sample t-test, t=6.69; P<0.0001; vulnerability not yet tested). Thus, although predator cues cause active avoidance, and reduced feeding, avoidance is not enhanced in vulnerable prey.
Verga-Lagier, A.*, Callaghan, M., Mitch, M., Kibak, H.
THE DOMINANT MUSSEL SPECIES VARIES FROM YEAR-TO-YEAR AT MOSS LANDING HARBOR, CALIFORNIA
California State University, Monterey Bay
At the turn of the century, Bay Mussels collected by California museums were exclusively Mytilus trossulusfrom San Diego to Alaska. When sampled again in the 1990s, genetic analysis demonstrated that all the native M. trossulus in Southern California had been replaced by the Mediterranean mussel, Mytilus galloprovincialis; the invasion going unnoticed due to the morphological similarity of the two sibling species. The invading mussel has now been found as far north as Puget Sound, but is still absent from many sites along the Northern California and Oregon coasts. It appears that Moss Landing Harbor is emerging as a dynamic hybrid zone where each species and hybrids exist. To capture a snapshot of this dynamic hybrid zone each year, we sampled the same floating dock in Moss Landing Harbor in 2010, 2011 and 2012, using two nuclear markers. In 2011 the native population was dominant, however, in 2012 samples collected from the same floating dock showed a significant decrease in the native population and an increase in the invasive species. Mussels collected in 2010 are being analyzed at the time this abstract was written.
Villalobos, C.1*, Grunbaum, D.2, and K.Y.K. Chan2, 3
IMPACTS OF OCEAN ACIDIFICATION ON FERTILIZATION SUCCESS AND EARLY DEVELOPMENT IN THE SAND DOLLAR, DENDRASTER EXCENTRICUS
1 California State University, Monterey Bay 2 University of Washington, 3 -Woods Hole Oceanographic Institution
Ocean acidification (OA), a result of increased atmospheric CO2, is predicted to decrease the surface ocean pH by a value of 0.4 units by the year 2100. Because fertilization success plays key roles in determining population dynamics of marine invertebrates, understanding OA impacts on fertilization is essential in predicting future ecological shifts. We investigated OA impacts on fertilization success of the sand dollar Dendraster excentricus by comparing the survival and developmental rates of embryos fertilized and maintained under different pH treatments. The two pH treatments reflect the present day, average surface ocean value (8.1) and the IPCC prediction for the year 2100 (7.7). Fertilization did not significantly differ between pH treatments, suggesting that, at least under high sperm concentration (103individual mL-1), fertilization success of D. excentricus was not affected by OA. We developed a numerical model to determine whether small changes in fertilization success can affect the reproductive success of the population when adult density and hydrodynamic environment are considered. Results of this investigation will aid future studies on the effects of climate change on marine organisms and the ecological stability of marine communities.
Waltz, G.T. 1*, Hall, N.C.1, Starr, R.M.2, Wendt, D.E.1
AN ASSESSMENT OF RECAPTURED NEARSHORE FISH SPECIES TAGGED USING STANDARDIZED FISHING METHODS IN CENTRAL CALIFORNIA
1 – Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, 2 –University of California Sea Grant Extension and Moss Landing Marine Laboratories
The California Collaborative Fisheries Research Program (CCFRP) has been monitoring four central coast marine protected areas (MPAs) since 2007. MPAs were sampled using two standardized fishing methods: 1) recreational hook and line fishing aboard commercial passenger fishing vessels (CPFVs) and 2) commercial live trap fishing from commercial fishing vessels. Part of this catch and release monitoring included tagging suitable nearshore fish (primarily Sebastes spp.) and providing a cash reward to anglers who reported tagged fish. Tag return data were analyzed from the Piedras Blancas State Marine Reserve (SMR), the Point Buchon SMR, and adjacent non-protected areas. The following parameters were calculated, by species, from the tag return information from 2007-2012: the distance between initial capture location and recapture location (recapture distance), the number of days at liberty, the relationship between initial fish size and recapture distance, and the relationship between the number of days at liberty and recapture distance. Tag return information from 2007-2012 indicated that the recapture distance for most tagged fish was not greater than a few hundred meters. These data may be used to assess whether the current size of the central coast MPAs are large enough to offer a refuge from fishing pressure.
Webster, C.M.*, Johnstone, A.
VENTILATION RESPONSES DURING INDUCED TONIC IMMOBILITY BETWEEN PORODEMA PANTHERINUM ANDHAPLOBLEPHARUS EDWARDSII
California Polytechnic State University: San Luis Obispo
Tonic immobility (TI) is an unlearned behavioral response characterized by a state of muscle relaxation and immobility exhibited in several taxa of elasmobranchs. The reasons for elasmobranchs to exhibit this behavior are as yet unclear. Studies have been conducted to find biological advantages for elasmobranch susceptibility to TI. The preliminary studies for this experiment did not detect a significant relationship between sex and TI duration or susceptibility, suggesting TI is not a reproductive adaptation. However, elasmobranchs repeatedly demonstrated deeper, more constant respiration rates during TI across different species and sexes. This study sought to determine if respiration rates could be correlated to the duration of TI episodes in two closely related elasmobranchs, the leopard catshark (Poroderma pantherium) and the puffadder shyshark (Haploblepharus edwardsii). Each species was artificially induced into a state of TI by manually inverting the sharks, while submerged. While exhibiting TI, the sharks ventilation rates were recorded. Average ventilation rates, during TI episodes, were significantly higher in leopard catsharks than the puffadder shysharks. A significant correlations between respiration rates and duration of TI was not found. Further studies need to be done to elucidate any correlation between ventilation rates and the associated physiological responses to TI.
Wood, M.E.*, Schneider, L., Nielsen, K.J.
SPATIAL AND TEMPORAL VARIATION IN CALCIUM CARBONATE CONTENT AND GROWTH OF ARTICULATED CORALLINE ALGAE IN NORTHERN CALIFORNIA
Sonoma State University
Ocean acidification (OA) affects the physiology, growth and survivorship of marine calcifying organisms including crustose coralline algae. Articulated coralline algae are abundant on intertidal rocky shores and play an important ecological role facilitating recruitment of kelps, surfgrasses and mussels and providing habitat to a diverse assemblage of microinvertebrates. Despite their ecological importance and abundance in the California Current Ecosystem, a region known to experience shoaling of low aragonite saturation state seawater, articulated coralline algae have not been a focus of OA research. We investigated spatial and temporal variance in growth and calcium carbonate (CaCO3) content of Corallina vancouveriensis at four sites in northern California. We found CaCO3 content and growth varied over bi-weekly time scales, and that CaCO3 content exhibited persistent rank differences among sites across two years. The site with the lowest CaCO3 content was closest to a known upwelling center (Point Arena, CA). pH and seawater temperatures varied substantially over weekly and shorter time scales, reflecting the highly dynamic nature of physical oceanographic processes and primary productivity of coastal waters. These results highlight the importance of investigations that incorporate realistic scales of frequency variance in pH treatments when considering the vulnerability of coastal ecosystems to OA.