Abstracts for 2013 WSN Meeting
November 7 – 10th, 2013
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.
HOW TO BE USEFUL? LESSONS FROM THE INTERSECTION OF SCIENCE AND DECISION-MAKING
California Ocean Science Trust
Being relevant to decision-makers is not nearly the same as being useful. At the California Ocean Science Trust, a dynamic team of scientists, administrators, communicators, and technologists lives this distinction every day. As a “boundary organization” dedicated to bringing science, management, and stakeholder communities together, we develop tools and institutional capacity that can benefit anyone struggling to make these connections. We help make the leap from just relevant to actually useful.
Boundary organizations like ours need to cultivate “dual accountability” in order to be successful. This means that for any given project or program, we do our best to live up to expectations of the various groups involved, which often have very different priorities, framings of problems, and languages for talking about an issue. We need our scientist partners to trust that we will represent their work accurately, and we need decision makers to trust that we understand their needs and constraints. While this position can be precarious, it is both humbling and gratifying to have multiple groups trusting and relying on us in this way.
In this talk I will give several examples of the many ways that this dual accountability function can play out in the complicated world of science, policy, and management. A common thread in these examples is our commitment to act as an honest broker of science and policy information, and to “lift all boats” in everything that we do. We believe that a healthy democracy and thriving scientific enterprise need boundary organizations, and we are working to reinforce that point through our own example in all that we do.
ENGAGING COMMUNITIES IN PARTICIPATORY ACTION RESEARCH TO SUPPORT CORAL REEF STEWARDSHIP IN THE HAWAIIAN ISLANDS
Center for Ocean Solutions, Stanford University
Human populations worldwide are highly reliant on the ocean and its resources for sustenance, livelihoods, and cultural continuity, but human activities increasingly place these resources and ecosystem services at risk. Despite broad recognition of the human role in ocean degradation, the vast majority of research focuses on the biophysical rather than the human dimensions of marine ecosystems, limiting our understanding of social relationships with these environments and potential solutions for managing toward sustainability. Moreover, there is an even greater need to engage stakeholders directly in the co-development of knowledge as well as to shape the potential solution space. In this talk, I provide an overview of participatory action research that engages communities and stakeholders in collaborative knowledge generation, with direct linkages to coral reef stewardship programs in the Hawaiian Islands. I will share novel methods and findings from participatory fishery assessments and recent efforts to quantitatively link fisheries ecology, ecosystem services, and community wellbeing at the local level. These collaborative research projects are directly supporting community-based management initiatives, with a range of challenges, opportunities, and surprises along the way. Critically, when users are engaged in the development of data and a shared understanding of the problems and potential solutions, they are more likely to support planning initiatives, creating enabling conditions for successful stewardship programs and the institutionalization of collaboratively designed policy. I will conclude with my own personal views on how research that engages stakeholders can help manage coral reefs toward more sustainable outcomes, and roles researchers can play to ‘move beyond the science’ in working toward solutions.
SCIENCE, STUPIDITY, & SMOOTHIES: BLENDING UP PALATABLE POLICY IN THE REAL WORLD
NOAA ,NMFS, Northwest Fisheries Science Center
Ecosystem-based management (EBM) is not a new idea, nor, I will argue, is it absolutely necessary for sustainable fisheries. However, fishing, even sustainably, has clear ecosystem and conservation consequences, and it is within this realm of multiple objectives and management mandates that EBM is critical. But, how do we actually do EBM? Now that resource managers and policy makers are embracing (or at least accepting) EBM in concept, there is somewhat limited practical advice on how to implement the tenets of EBM. Despite a reasonable understanding of many of the social and biogeophysical components of marine ecosystems, we lack a framework or process for using science to inform decision making about multiple interacting management objectives. In this talk I will outline an approach to inform resource management decisions. This approach allows us to make incremental progress towards EBM given current management, policy and legal constraints. However, the approach is broadly applicable and will be useful to more comprehensive large-scale EBM in the future.
THE NEGLECTED IMPORTANCE OF LOCAL ADAPTATION IN THE SEA
Bodega Marine Laboratory, University of California Davis
Historically, marine species with planktonic larvae were thought to be broadly dispersed and genetically homogeneous over large spatial scales. As a result, local adaptation in the sea was regarded as a rare phenomenon, and ecologists seldom considered the influence of contemporary evolutionary processes on marine communities. However, an emerging paradigm suggests that adaptive genetic differentiation among marine populations is more common and ecologically important than traditionally recognized. A growing body of research indicates that adaptive divergence among populations and sub-populations occurs over a range of spatial scales, including those that are fine-grained (i.e., meters to kilometers), reflecting a balance between scales of gene flow and selection imposed by environmental heterogeneity. I will discuss how increased attention to the causes and consequences of adaptive genetic differentiation among marine populations promises to advance key areas of marine ecology, including studies of population connectivity, climate change impacts, and conservation.
BIODIVERSITY AND ECOSYSTEM FUNCTIONING: CONTRIBUTIONS FROM MARINE SYSTEMS TO THE EVOLUTION OF A PARADIGM?
University of California Davis
At the turn of the 21st century, theory and limited data from terrestrial systems argued for a link between biological diversity and ecosystem “functions” such as productivity, stability and nutrient cycling. At that time, virtually no data examined this question in marine systems. Since then, dozens of experiments manipulating marine biodiversity have been conducted. What have we learned from these studies about the ecological role of marine biodiversity? More generally, what has this work contributed to the developing paradigm that diversity is linked to ecosystem functioning? In this talk I’ll take two approaches to answering this question. First, I’ll discuss how marine experiments in a range of systems have tested and / or extended the paradigm to include cross-trophic level interactions and diversity below the species level. Second, I’ll discuss results from a decade long biodiversity manipulation in the rocky intertidal zone of northern California that examined the effect of seaweed and grazer diversity on community structure and functioning. Research on this topic is diverging in two complementary directions: (1) application of the paradigm to conservation and management objectives and (2) developing increased mechanistic understanding of the trait-based differences among species that underpin diversity effects.
Harley, C.D.G.*, O’Connor, M.I.
PARADIGMS IN CLIMATE CHANGE ECOLOGY: WHAT WE NEED VS. WHAT WE HAVE
University of British Columbia
An ever-increasing proportion of the ecological literature is devoted to exploring the effects of ongoing and future changes to the earth’s climate. However, unlike many other hot topics in the ecological literature, there has been relatively little emphasis on establishing, debating, and testing a conceptual framework to guide and motivate this work. Rather, the climate change ecology literature reads like a series of loosely connected case studies and, as a result, its predictive power is largely restricted to systems and species for which we already have data. Here, we discuss the advantages of formalizing a paradigm (or paradigms) for climate change ecology. We propose that central elements of such a paradigm already exist in other subdisciplines, including metabolic ecology, physiological ecology, and ecomechanics. These elements can be productively used to guide future research, and could greatly expand the breadth of predictions that can be extended from a finite number of studies. Although no single paradigm will answer every question related to the ecology of climate change, a few small steps towards establishing a testable conceptual framework could result in a rapid increase in our understanding of climate change impacts.
Aalto, E.A.1,2*, Baskett, M.L.1
OBLIGATE PREDATION DELAYS POST-HARVEST SIZE-DISTRIBUTION RECOVERY IN SIZE-SELECTIVE FISHERIES
1 – University of California, Davis, 2 – Hopkins Marine Station
Empirical observations and theoretical predictions show that fisheries can truncate target species size distribution by selectively removing larger individuals. It is less clear, however, how quickly populations revert to pre-harvest distributions after implementation of no-take policies by fisheries managers. In particular, the presence of a strongly interacting size-specific predator may interfere with the recovery of a targeted prey species. We used a two-species size-structured model to examine how gape-limited predation alters post-harvest recovery for three example species, cod, haddock, and whiting. We found that there was little difference in recovery time between the generalist predation and no-predation models. However, gape-limited obligate predation delays the recovery of large prey individuals to pre-harvest abundance, even for sizes not targetable by the predator. In addition, the obligate predator lowers the relative abundance of smaller vulnerable individuals, delays the shift to pre-harvest size distribution, and can complicate post-harvest monitoring through the presence of population cycles. We conclude that the presence of a strong dynamically-linked predator can interfere with the rapid recovery predicted from single-species management models, particularly for smaller-bodied fish with greater lifetime exposure to predation.
† Abadía-Cardoso, A.1*, García de León, F.J.2, Mayden, R.L.3, Garza, J.C.1
MEXICAN TROUT COMPLEX: EVIDENCE FOR MORE THAN JUST JUAN SPECIES
1 – Southwest Fisheries Science Center and University of California, Santa Cruz, 2 – Centro de Investigaciones Biológicas del Noroeste, S.C., 3 – Saint Louis University
Trout inhabiting northwestern Mexico are the southernmost native salmonid populations in the world, and the least known in North America. They are unfortunately also facing threats to their continued existence. Previous work has described one species, the Mexican golden trout (Oncorhynchus chrysogaster), and one subspecies, Nelson’s trout (O. mykiss nelsoni) in Mexico, but preliminary analyses indicate that there is more biodiversity than what has been described. We conducted a comprehensive genetic analysis of these trout by using novel genetic markers and techniques to elucidate the biodiversity of trout inhabiting northwestern Mexico, compared it to that of other species of Pacific trout, evaluate hypotheses regarding their evolutionary history, and measure introgression from non-native hatchery rainbow trout. Our study revealed significant divergence between Mexican trout and the other species. We confirmed the vast genetic diversity present in the Mexican trout complex and the extremely strong genetic differentiation, not only between basins but also at a smaller scale. We also found that introgression from non-native rainbow trout is present, but the genetic integrity of native trout is still maintained in many watersheds. This information will help to guide effective conservation strategies for this globally important group of fishes.
† Abbott, J.M.*, Stachowicz, J.J.
The effects of genetic relatedness and functional trait differences on the performance of pairs of eelgrass (Zostera marina) genotypes
Bodega Marine Laboratory, University of California Davis
Genetic diversity within key species has been increasingly tied to the performance of entire communities. Many genetic diversity studies use only the number of genotypes as a metric of diversity. 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 eelgrass (Zostera marina) performance by growing pairs of eelgrass genotypes with known pairwise relatedness and trait measurements in the field for a year. Genotypic richness, identity, and trait distance all interactively influenced the performance of eelgrass pairs. After a year, one genotype had been excluded in 60% of the plots. Trait distance and genotypic identity both affected the rate of exclusion. Pairs with greater trait distance where more likely to have one genotype dominate, suggesting that similar genotypes may be competitive equals. Trait distance increased biomass accumulation, but only in plots where a single genotype remained. All plots where both genotypes persisted achieved similarly high biomass regardless of trait distance, suggesting complementarity when genotypes coexist. Pair relatedness was not correlated with biomass or exclusion rate, however leaf growth rate increased with relatedness in plots where only one genotype persisted. Our work shows that the identity and trait similarity of genotypes determines whether genotypes coexist, while the number of persistent genotypes and past competition influences performance.
† Abboud, S.S.*, Gómez Daglio, L., Dawson, M.N.
DIVERSITY AND SPATIAL SCALES OF GENETIC STRUCTURE WITHIN JELLYFISHES
University of California, Merced
Spatio-temporal variation in abundances of jellyfishes occurs on scales ranging from tens of meters to hundreds of kilometers and hours to decades, but inter- and intra-specific variation is unknown. In this study, we describe genetic diversity within jellyfishes to identify spatial scales of genetic differentiation, including estimating the proportion of taxa comprised of multiple distinct evolutionary significant units (ESU). Our data set includes 14 scyphozoan genera and one hydrozoan genus sampled from different biogeochemical provinces, which are used for jellyfish population dynamic analyses due to varied province community composition. For a global comparison we sampled 3 individuals from different provinces across each genus’ range; for a regional comparison we sampled 6 individuals each from 2-4 locations within a single province. We sequenced mitochondrial cytochrome c oxidase subunit I with which we estimated within- and between-location variation. We found heterogeneity at a range of scales—global, province, and local. Approximately 70% of inter-provincial comparisons represent species-level differences. Approximately 75% of intra-provincial comparisons were species-level or ESU-level differences. We conclude there is greater spatial genetic variation within jellyfishes than initially considered. Spatial scale is an important consideration when framing questions about jellyfish species and population dynamics.
Adam, T.C.1*, Burkepile, D.E.1, Ruttenberg, B.I.2
PHYLOGENETIC HISTORY DRIVES NICHE COMPLEMENTARITY IN CARIBBEAN PARROTFISHES
1 – Florida International University, 2 – NOAA Southeast Fisheries Science Center
Herbivory is an important process on coral reefs that can facilitate reef-building corals by controlling algae. On most coral reefs, algae are grazed by a diverse assemblage of herbivorous fishes and invertebrates, yet the functional significance of this diversity is largely unknown. Therefore, an important question is how much functional diversity exists within the herbivore guild, and how do human activities such as fishing and habitat degradation alter this diversity. Parrotfish are among the most important herbivores on many Pacific and Caribbean reefs and are often targeted in artisanal fisheries. To investigate the level of functional diversity that exists among parrotfishes in the Caribbean, we documented habitat-use, diet selection, and foraging behavior of nine species—which vary widely in there susceptibility to fishing—in the Florida Keys National Marine Sanctuary. We found large differences in diet selection that were well predicted by phylogenetic history, with closely related species feeding on similar types of algae. We also found complementary patterns of diet and habitat-use, suggesting that competition for food among closely related species is an important factor driving habitat selection. Thus, our results revealed similarities and differences in diet and behavior of Caribbean parrotfishes that have important implications for fisheries management.
Adreani, M.S.*, Steele, M.A.
FECUNDITY, SPAWNING FREQUENCY, AND PRODUCTIVITY OF TEMPERATE REEF FISH; A COMPARISON OF NATURAL AND ARTIFICIAL REEFS
California State University Northridge
The reproductive output of fishes is often used as a measure of the health and productivity of a given population. This measure may be of particular importance when habitat is altered in some way. Artificial reefs may provide new space for fishes to inhabit, but it is unclear whether fishes reproduce at the same rate on natural and artificial reefs. We tested whether the overall reproductive output on a large artificial reef was similar to nearby natural reefs using three of the most abundant species on rocky reefs in the Southern California Bight (California sheephead, kelp bass and senorita). Fish were collected during their reproductive season from 2009-2013 and we measured a range of reproductive parameters, including batch fecundity, spawning frequency and spawning season length using visual assessments, hydrated egg counts and gonad histology. While there was variation in the specific measures, our estimates of reproductive output for each of the three species were similar across all of the reefs. These results, along with additional estimates of overall reef productivity, suggest that artificial reefs have the potential to mitigate damages incurred to natural reefs and give us additional insight into the reproductive ecology of these ecologically important species.
† Ahr, B.J.*, Farris, M.R., Lowe, C.G.
HABITAT SELECTION OF WHITE CROAKER (GENYONEMUS LINEATUS) IN THE LOS ANGELES AND LONG BEACH HARBORS
California State University Long Beach
Sediment contamination of DDT and PCBs within the Los Angeles and Long Beach Harbor has been a continuing environmental concern due to the negative effects these contaminants have on marine organisms and human health. White croakers (Genyonemus lineatus) are a sentinel fish species for contamination due to their susceptibility to pollutants and direct interaction with contaminated sediments through their benthic foraging behavior. Acoustic telemetry, fractal analysis, and mixed effect models were used to determine white croaker movements and habitat selection in the LA-LB Harbor. White croakers exhibited a diel shift in depth and occupied shallower depths at night than during the day. Time of day and region of the harbor were important predictors of depth use. No diel difference indicative of foraging behavior was observed; however, a seasonal difference in potential foraging behavior was observed in the movement analysis. White croakers spent significantly more time per unit area in sections of the harbors with the highest polychaete density (300-960 polychaetes/0.1m2) in comparison to medium (150-290 polychaetes/0.1m2) and lower densities (30-140 polychaetes/0.1m2). Potential prey availability and depth combined with a temporal component are key predictors in white croaker habitat selection and indicate areas where fish may be acquiring contaminants from sediment.
Allen, L.G.*, Hawk, H.A.
AGE AND GROWTH OF GIANT SEA BASS, STEREOLEPIS GIGAS
California State University, Northridge
The giant sea bass, Stereolepis gigas, is the largest bony fish inhabiting the southern California kelp forest community. It is a critically endangered species, yet little is known about its life history. A more complete knowledge of the life history of this once commercially-viable fish is necessary before an effective management strategy can be proposed. This study marks the first attempt to construct an age-and-growth model for the over-fished giant sea bass. A total of 61 samples was obtained for age-and-growth analysis through collaborative efforts with commercial fish landings and scientific gill-netting. Sagittal otoliths were cross sectioned and analyzed with digital microscopy techniques, resulting in the verification that S. gigas is a long–lived species attaining at least 76 years of age. The von Bertalanffy growth equation (R2 = 0.932) was calculated to describe growth in this species and yielded the growth parameters L∞ = 2066.1, k = 0.041, and t0 = −.775. Long-lived species that are slow to reach maturity often have a low resilience to over-fishing. Therefore it is of paramount importance that we continue to collect essential life history data on this species in order to more effectively protect and manage the S. gigas population.
Anderson, S.S.1,2*,Steele, M.A.3, Wormald, C.L.2,3, Lambrinos, J.G.4, Anderson, S.S.2
The Cook Islands: A Test Bed For Relaxed Human Exploitation Of The Coast
1 – Pacific Institute for Restoration Ecology, 2 – California State University Channel Islands, 3 – California State University Northridge, 4 – Oregon State University
The Cook Islands is a Polynesian nation with a settlement and resource exploitation history similar to many of its sister nations across the Pacific. In recent years, however, the Cooks began to follow a quite different exploitation trajectory. Over the past 15 years, the outer islands have seen their human populations shrink to one-third (or less) of their late 1990s numbers. This stands in stark contrast to most Pacific Islands and coastal zones worldwide which are harboring both more individuals as well as a greater proportion of our planet’s overall population. While offshore, pelagic fisheries are suffering from transnational fishing pressure, most reef-based fish and invertebrate populations appear to be fairing comparatively well. We will present our general overview of the current state of marine and terrestrial resources in the Cooks as well discuss the Cooks’ current MPA planning efforts, particularly in light of the disingenuous Kiribati/Phoenix Islands MPA fiasco.
† Anthony, S.E.*, Palmer, A.R.
CHOOSE YOUR WEAPON: CNIDAE SEQUESTRATION OF AEOLID NUDIBRANCH HERMISSENDA CRASSICORNIS
University of Alberta, Bamfield Marine Sciences Centre
Cnidae, also known as nematocysts, are harpoon-like capsules formed by cnidarians such as corals, anemones, and jellies for prey capture, defense, and attachment. They have many different shapes and sizes related to their function; some have short spines, others are thread-like. Aeolid nudibranchs are famous for their ability to eat cnidarians and steal cnidae for their own defense. However, some forms of cnidae may be more effective against seastars with soft-tissue whereas others may be more effective against crabs with hard exoskeletons. We tested whether cnidae complements of aeolids are affected by prey availability and by predator identity via laboratory experiments with the generalist sea slugHermissenda crassicornis, found in abundance around Bamfield, BC, Canada. We provided four species of cnidarians ad libitum to H. crassicornis that were exposed to the effluent of kelp crab Pugettia producta(predator 1), rose seastar Crossaster papposus (predator 2), and C. papposus consuming other H. crassicornis (predator 2 + scent of damaged conspecifics). After three weeks, we observed no significant difference among the treatment groups, although cnidae complements differed significantly before and after the experiment. Cnidae complements therefore appear to depend more on food ability than on predator identity in this sea slug.
Aquilino, K.M.1*, Byron, S.N.1,2, Moore, J.D.2,3, Rogers-Bennett, L.2,3, Neuman, M.J.4, Cherr, G.N.1
BEYOND LABORATORY ROMANCE: MAPPING THE ROAD TO WHITE ABALONE (HALIOTIS SORENSENI) RECOVERY
1 – Bodega Marine Laboratory, University of California, Davis, 2 – California Department of Fish and Wildlife, 3 – Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, 4 – NOAA, NMFS West Coast Region
Historically, an estimated 300,000 white abalone (Haliotis sorenseni) ranged from Point Conception to Baja California; however, severe over-fishing led to the species being the first marine invertebrate listed as endangered under the Endangered Species Act. Following its listing in 2001, captive breeding and outplanting were identified as critical to the recovery of this species, with models suggesting that the population will shrink to fewer than 1,000 individuals in the next 10-15 years in the absence of outplanting. Over the past two years, we have celebrated the first instances of successful captive white abalone reproduction in nearly a decade. While the new progeny will contribute to the captive broodstock, greater reproductive output is required before outplanting is feasible. As we look ahead, we consider strategies for increasing captive reproduction and for successfully releasing captive-bred white abalone in the wild.
Baghdasarian, G.1*, Mihora, D.C.1, Osberg, A.W.1, Putnam, H.M.2, R.D. Gates2, Edmunds, P.J.3
THE EFFECTS OF TEMPERATURE AND HIGH pCO2 ON THE REGULATION OF POPULATION DENSITY OFSYMBIODINIUM SPP. IN A TROPICAL REEF CORAL
1 – Santa Monica College, 2 – University of Hawaii / Hawaii Institute of Marine Biology, 3 – California State University Northridge
By 2100, global climate change is predicted to result in increases in oceanic surface temperatures of 1.1-6.4 °C, and reduced pH levels of 0.14-0.35. In this study, we consider the effects of elevated temperature and pCO2 on population regulation of symbiotic algae (Symbiodinium) in juvenile colonies of the coralSeriatopora caliendrum from Taiwan. Treatments were designed to assess individual and combined effects of temperature (ambient 28.0 vs. 30.5°C) and pCO2 (ambient 41Pa vs. 91Pa) over 11 days. Elevated temperature depleted Symbiodinium population (i.e. bleaching occurred) independent of pCO2, but theSymbiodinium remaining in the corals were also affected. Post-treatment Symbiodinium populations in corals exposed to higher temperature and/or high pCO2 were characterized by 35% lower mitotic index, 47% higher total chlorophyll content, and a 28% decline in the ratio Chla:Chl c2 (i.e., favoring Chl c2). These changes could be a functional consequence of: a) physiological response of the Symbiodiniumcountering the effects of high temperature and high pCO2; b) physiological changes that are a cause of, or are associated with, bleaching; or c) a selection of Symbiodinium phenotypes with different physiological attributes. Analyses are underway to determine whether genetic variants of Symbiodinium were differentially affected by treatments.
Bahr, K.D.1,2*, Rodgers, K.R.2, Jokiel, P.L.2
RESPONSE OF HAWAIIAN REEF CORAL, MONTIPORA CAPITATA, TO MULTIPLE CLIMATE CHANGE STRESSORS
1 – University of Hawaii at Manoa, 2 – Hawaii Institute of Marine Biology
Numerous environmental factors (e.g. irradiance, temperature) that regulate coral calcification rates and productivity are predicted to change alongside future elevated carbon dioxide emissions. Therefore, an experiment was performed in continuous flow mesocosms under full solar radiation to describe the growth, mortality and bleaching response at the upper lethal temperature threshold of the Hawaiian reef building coral Montipora capitata. Using a split plot design, corals were grown under treatments differing in temperature (summer ambient at ~27oC and heated to ~29oC), CO2 (present day and 2X present day levels), and ambient irradiance (100%, 50% 8%) operating independently and together, to test the effect each factor independently, as well as pairwise comparison of these variables, and interactions of all three. Light stress was determined to have the strongest influence on coral growth, mortality, and bleaching. Low light levels potentially provide refuge for M. capitata from thermal and irradiance stress; however, these corals may be more susceptible to OA stress.
Baker, R.B.1,4*, Lewis, N.S.2,4, Henkel, S.K.3,4
ASSESSING INFAUNAL INVERTEBRATE COMMUNITIES AMONG REPLANTED AND NATURAL ZOSTERA MARINABEDS
1 – Department of Biology, University of Idaho, 2 – Marine Resource Management, Oregon State University, 3 – Department of Zoology, Oregon State University, 4 – Hatfield Marine Science Center, Oregon State University
Eelgrass (Zostera marina) plays an important role in promoting stable marine ecosystems, cycling nutrients and stabilizing sediment, providing food and refuge for fish and invertebrates, which in turn serve as food sources. One group of invertebrates, benthic infauna, have been shown to promote the health of eelgrass communities, specifically by enhancing seed burial. A native eelgrass bed in Yaquina Bay, Oregon, was disturbed during construction of a large pier. The disturbed eelgrass was replanted in a new location as a mitigation measure. In order to evaluate the recovery of this mitigated eelgrass bed, we compared eelgrass percent cover, sediment characteristics, and benthic infaunal communities between this site and two undisturbed eelgrass beds. We found that despite a low percentage of eelgrass coverage at the replanted mitigation site, there was not a significant difference in sediment characteristics and infaunal communities between this site and one of the undisturbed reference sites. There were significant correlations between certain taxon abundances and particular sediment characteristics but no significant correlations between taxa and eelgrass coverage. We conclude that benthic infauna are not correlated with eelgrass coverage and are likely highly resilient to a great degree of disturbance.
† Barner, A.K.*, Hacker, S.D., Menge, B.A.
DOMINANT ALGAL CANOPY-UNDERSTORY INTERACTION MODIFIED BY LOCAL, NOT REGIONAL ENVIRONMENTAL CONDITIONS
Oregon State University
Understanding the scale of variation in species interactions may be critical for predicting the consequences of changing environmental conditions on communities. We investigated variation in the interaction between a canopy kelp (Saccharina sessilis) and its understory community in the rocky intertidal of the US Pacific coast. We asked, (1) What is the strength and sign of the interaction between canopy algae and understory organisms? (2) Does the interaction vary along a large-scale oceanographic gradient or small-scale wave exposure gradient? We conducted two experiments at different spatial scales with the same treatments: control, kelp removal, and understory removal. We established the first experiment at 10 sites in 4 regions of the Oregon and California coasts. The second experiment was conducted at 3 locations along a wave exposure gradient at a single site in Oregon. We found that the interaction between canopy kelp and understory turf was stable regionally across 100’s of kilometers (oceanographic gradient), but differed across local scales (wave exposure gradient). Across all sites there was a positive effect of turf on the persistence of the canopy kelp. However, within a single site, the positive effect of turf on kelp was only found at intermediate levels of wave exposure.
† Barr, R.J.1,2*, Baskett, M.L.2, Botsford, L.W.2
A COMPARISON OF MARINE RESERVES AND ROTATING CLOSURES IN SPATIALLY-STRUCTURED POPULATIONS
1 – San Diego State University, 2 – University of California, Davis
Spatial structure in population dynamics, such as spatial and temporal variability in larval productivity, inevitably affects spatially explicit fisheries management. Although permanent no-take areas, i.e. marine reserves, have become a popular tool to conserve biomass, rotating closures might provide a more adaptive solution to both conserve and utilize built-up biomass, but achieving such benefits might rely on knowledge and consistency of the spatial structure of the population. We construct an age-structured population model with spatially-structured larval productivity to compare the relative efficacy of marine reserves and rotating closures at achieving conservation and fishery management goals. Given a population with a static larval source, rotating closures outperform a permanent reserve in the sink but underperform a permanent reserve in the source in terms of biomass and yield. When the location of the larval source varies in time, permanent reserves generally sustain higher biomass but rotating closures allow for higher fishery yield, and these results are robust to uncertainty in the location of the larval source in any given year. The optimal management strategy therefore depends on both the temporal stability of the spatial structure of the population and the balance of conservation and fishery goals.
† Beas-Luna, R.*
PREDICTING THE EFFECT OF CLIMATE CHANGE ON A CENTRAL CALIFORNIA KELP FOREST FOOD WEB
University of California, Santa Cruz
Kelp forests are among the most productive ecosystems. They provide numerous important ecosystem services, which are subject to different sources of variation. For instance, climate change has been identified as one of the most pressing environmental issues, directly affecting coastal marine ecosystems. Changes in the sea surface temperature (SST) of the California current has recently attracted attention, as it might affect many ecosystems, including the kelp forests along California’s coastline. Here we used a food web couple with time series to simulate how changes in oceanographic conditions associated with climate change might alter the structural and functional attributes of a kelp forest ecosystem along central California. We parameterized the model with natural history traits, ecological monitoring datasets, and expert knowledge from the kelp forest database (kelpforest.ucsc.edu). We used kelp biomass time series combined with SST and upwelling index data to perform a resampling procedure to simulate increasing temperature and upwelling. Our results suggest that understory algae and canopy kelp are inversely related in terms of production. However, the overall system’s biomass density is reduced. This study highlights the value of integrating physical and biological time series, natural history traits and ecosystem models to better understand ecosystems threaten by environmental changes.
SURVEYING BENTHIC INVERTEBRATES IN PUGET SOUND TO ENGAGE INTERDISCIPLINARY UNDERGRADUATE STUDENTS IN CONSERVATION BIOLOGY
University of Washington Tacoma
Long-term ecological monitoring by undergraduate students provides an opportunity to collect useful data while providing highly-relevant training for future professionals. A conservation biology course was designed around a large class project, repeating part of a WA Department of Ecology monitoring effort in Puget Sound. Students followed protocols from a technical report, collected benthic samples and associated environmental data, sorted and identified all of the organisms, calculated a number of indices using their data, interpreted their results compared to past years, wrote a group technical report and presented their data to community partners. Self-assessment of student confidence with associated skills was conducted at the beginning and end of the course, as was a test of student attitudes about environmental issues. Qualitative data were also collected on student perception of the relevance of the material to their career goals. Student motivation and engagement were greatly enhanced by the project-based nature of the course. The protocols and assignments created for this class has formed the basis of a long-term monitoring program associated with this course and a number of independent student capstone projects. The course continues with modifications based on lessons learned.
Bell, T.W.*, Cavanaugh, K.C., Reed, D.C., Siegel, D.A.
PRIMARY CONTROLS ON GIANT KELP BIOMASS THROUGHOUT CALIFORNIA
University of California, Santa Barbara
Giant kelp (Macrocystis pyrifera) serves as a foundation species that plays a dominant role in structuring nearshore communities, and is particularly important along the California coast. Biomass has been found to be the most important factor to net primary productivity and is driven by a suite of biological, physical and anthropogenic forcings, which vary significantly over space and time. We used remotely sensed biomass estimations from 1984 – 2011 for the entire dominant range of giant kelp along the CA coastline, and determined the dominant forcings on kelp biomass using empirical orthogonal function (EOF) analysis. At a 500m coastline scale, wave disturbance was found to be the most important control on kelp biomass followed by sea surface temperature, which served as a proxy for nutrient availability. We confirmed these results with a spatially explicit wave model and SST dataset. These controls were followed by the North Pacific Gyre Oscillation (NPGO), which serves as a potential driver of biomass, particularly in the SE Southern CA Bight. We are using these forcings to inform a generalized additive model to understand the relative impact of these forcings on giant kelp biomass dynamics along the CA coast.
† Bible, J.M.*, Sanford, E.
VARIATION IN SALINITY TOLERANCE OF OLYMPIA OYSTERS: IMPLICATIONS FOR RESTORATION IN THE FACE OF CLIMATE CHANGE
Bodega Marine Laboratory, University of California Davis
Although seldom studied, genetic differences among marine populations may mediate a species’ response to climate change. We examined whether populations of native Olympia oysters (Ostrea lurida) in northern California are locally adapted to salinity, a factor predicted to shift with climate change. In a first experiment, we spawned oysters from three sites in San Francisco Bay and raised their offspring under common laboratory conditions. These juvenile oysters were then reciprocally transplanted among the three field sites. There was suggestive evidence that oysters of local origin survived better than oysters from other source populations, consistent with local adaptation within a single estuary. In a second experiment, we raised oysters from two sites in San Francisco Bay and one site in Tomales Bay through two generations under common laboratory conditions and then subjected these oysters to different salinity regimes in the laboratory. Oysters that originated from the field site exposed most frequently to low salinity were more tolerant of these conditions, suggesting varying selection among populations. As interest grows in restoring heavily impacted native oyster populations, our results suggest that considering local adaptation may be critical to deciding how and where to conserve and restore native oysters faced with changing ocean conditions.
Bignami, S.1*, Sponaugle, S.1,2, Cowen, R.K.1,2
Effects of ocean acidification on the larvae of a high-value pelagic fisheries species, mahi-mahi (Coryphaena hippurus)
1 – Rosenstiel School of Marine and Atmospheric Science, University of Miami, 2 – Oregon State University
Impacts of CO2-induced ocean acidification on marine organisms have proven to be variable both among and within taxa. This is especially true of fishes, highlighting the limitations of a nascent field with a narrow scope of study species. We present data from a series of experiments on the larvae of mahi-mahi (Coryphaena hippurus), a large pelagic species of high economic value. Mahi-mahi larvae were raised for up to 21 d under projected scenarios of ocean acidification ranging from 770 to 2170 µatm pCO2. Evaluation of hatch rate, size, development, swimming activity, swimming ability (Ucrit), and otolith (ear stone) formation produced few significant effects. However, larvae exhibited significantly larger size-at-age and faster developmental rate during one experiment, possibly related to a corresponding decrease in routine swimming velocity. Furthermore, microscopy and micro-computed tomography analysis of otoliths revealed significantly larger otoliths at 2170 µatm pCO2, and a similar but non-significant trend at 1200µatm pCO2. These data provide an optimistic indication that mahi-mahi may not be overtly susceptible to ocean acidification. However, the presence of some treatment effects implies the possible presence of other unmeasured or undetected impacts of acidification on mahi-mahi larvae, the cumulative consequences of which are still unknown.
† Bonsell, C.E.*
SEARCHING FOR MULTIDECADAL CHANGE IN THE SAN DIEGO ROCKY INTERTIDAL
Scripps Institution of Oceanography, University of California San Diego and University of Texas at Austin
Historical surveys offer potentially valuable baseline data for the evaluation of long-term change. This study is based on two historical ecological surveys at two rocky intertidal sites (Dike Rock and Ocean Beach) in San Diego, California. The surveys are notable in that they overlap with or predate a major oceanographic climate shift in Southern California in the late 1970s. Although the 2012 surveys showed that the invertebrate communities at both sites had changed since the historical surveys, the changes were dissimilar. While both sites lost and gained a few invertebrate species, notably losing the predatory whelk Nucella emarginata and gaining another in Mexacanthina lugubris, species abundances at Dike Rock increased while those at Ocean Beach decreased. This may be due to the different substrates at the sites: the sandstone of Ocean Beach may have been more impacted by a changing wave climate than the basalt of Dike Rock. However, the lack of dramatic changes overall indicates the resilience of rocky intertidal communities to human impacts and the effects of climate change.
† Brower, J.P.*, Anderson, T.W.
PREDATION THREAT INFLUENCES BEHAVIOR, PHYSIOLOGICAL STRESS, AND SUBSEQUENT PREDATION RISK IN A MACROPHYTE-ASSOCIATED FISH
San Diego State University and the Coastal and Marine Institute
Animals experience stress from several sources, including the presence of predators. Effects on physiological stress in fishes have been examined primarily in aquaculture settings, but little information exists on stress responses in a more natural context. In this study, we examine the effects of predation threat on the behavior and physiological stress of juvenile giant kelpfish (Heterostichus rostratus), a common macrophyte-associated fish. Experiments were conducted to assess behavioral and physiological responses of kelpfish to predators (kelp bass, Paralabrax clathratus), non-predators (black perch, Embiotoca jacksoni), and a control (no fish) and to evaluate the influence of structural habitat complexity on a stress response. Juvenile giant kelpfish responded to a visual stimulus of predation threat by distributing themselves consistently farther away from a predator vs. a non-predator and a control. Direct exposure of kelpfish to predators and non-predators yielded elevated but similar cortisol concentrations in both small and large arenas, but kelpfish exhibited different cortisol concentrations under predation threat with varying structural habitat complexity. Finally, fish with prior exposure to predators experienced lower predation mortality than fish without such exposure, suggesting that changes in behavior or physiology from predation threat have important consequences.
Byrnes, J.E.K.1*, Gamfeldt, L.2, Isbell, F.3, Lefcheck, J.S.4, Griffin, J.N.5, Duffy, J.E.4
MEASURING THE EFFECTS OF ENVIRONMENTAL CHANGE ON MULTIPLE ECOSYSTEM FUNCTIONS: EXAMPLES FROM SEAGRASS ECOSYSTEMS
1 – University of Massachusetts Boston, 2 – University of Gothenburg, 3 – University of Minnesota, 4 – Virginia Institute of Marine Science, 5 – Swansea University
The theme of environmental change altering single ecosystem functions is persistent across ecology and conservation biology. Biodiversity loss affects primary production. Climate change alters rates of nutrient cycling. Eutrophication changes net ecosystem respiration. However, the effects of environmental change on ecosystem multifunctionality – the simultaneous performance of multiple functions remains largely unexplored despite the possibility of environmental change having far different effects on multiple rather than single functions. For example, the biodiversity ecosystem function literature hints that the consequences of species diversity loss may be stronger if we consider multifunctionality as a response rather that any single function. How can we incorporate multifunctionality into our work? How do we quantify it and make the concept operational? Here, we use an example from a seagrass grazer diversity manipulation to examine several techniques of measuring multifunctionlity. We synthesize them into a single broadly adaptable framework. We provide a set of tools so that other researchers can move beyond the limiting paradigm of assessing change to single functions to a far more holistic understanding of shifts in ecosystem function.
Byron, S.B.1,2*, Aquilino, K.M.1, Marshman, B.C.2, Moore, J.D.2,3, Rogers-Bennett, L.2,3, Neuman, M.J.4, Cherr, G.N.1
WHITE ABALONE, Haliotis sorenseni, RECOVERY PROGRAM: LARVAL REARING TO BROODSTOCK REPRODUCTIVE CONDITIONING
1 – Bodega Marine Laboratory, University of California, Davis, 2 – California Department of Fish and Wildlife, 3 – Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, 4 – NOAA, NMFS West Coast Region
Successful captive production of juvenile white abalone occurred in 2012 and 2013 as a result of efforts at the UC Davis Bodega Marine Laboratory (BML) and partnering institutions. Using a hydrogen peroxide spawning technique, and the larval and juvenile culture facilities at BML, we have nearly tripled the number of captive broodstock in the program. Maintaining abalone health through all life stages has been critical to captive breeding success. Principal threats to captive white abalone populations are withering syndrome, shell-boring organisms that facilitate opportunistic pathogens, and harmful algal blooms. An oxytetracycline bath treatment developed in our laboratory has been used to effectively eliminate the pathogen responsible for withering syndrome in captive populations, and by coating the shell of each animal with liquid wax we eliminate boring organisms. In combination with methods for spawning, culturing, and health maintenance, we are testing the effectiveness of reproductive conditioning techniques by manipulating temperature, photoperiod, and diet. The success of the White Abalone Recovery Program depends on having an abundance of healthy progeny to one day outplant into the wild.
† Castorani, M.C.N.1*, Glud, R.N.2, Hasler-Sheetal, H.2, Holmer, M.2
FACILITATION OR INHIBITION? IMPACTS OF BLUE MUSSELS ON EELGRASS ACROSS A LIGHT GRADIENT
1 – University of California, Davis and San Diego State University, 2 – University of Southern Denmark
Impacts by habitat-modifying species can vary based on abiotic conditions, but this idea has seldom been tested in marine ecosystems. The blue mussel (Mytilus edulis) modifies the structure and biogeochemistry of the seafloor, thereby influencing other benthic species. Previous studies suggest that effects of bivalves on seagrasses can vary from facilitative to inhibitive depending on environmental conditions, but this idea had yet to be tested. We assessed whether light moderates the effects of blue mussels on eelgrass (Zostera marina). In eelgrass mesocosms, we factorially manipulated mussel abundance (presence/absence) and light intensity (high/low). After four weeks, we determined changes to benthic biogeochemistry, as well as eelgrass growth, morphology, and phytochemistry. Mussels increased porewater nutrients only in high light, but fertilization did not translate to higher eelgrass tissue nitrogen. Mussels increased concentrations of sediment sulfides (FeS), but only increased porewater sulfides under high light, and stable-isotope analysis revealed sulfide intrusion of eelgrass roots and rhizomes. Despite strong biogeochemical changes, mussels had no effects on eelgrass condition. Eelgrass thrived under high-light, while shaded plants grew more slowly and eventually deteriorated, with no lateral shoot production. We conclude that eelgrass is generally resilient to mussels and their effects on biogeochemistry, even under stressful conditions.
Catton, C.A.1,2*, Rogers-Bennett, L.2,3, Leichter, J.J.1
DENSITY-DEPENDENCE OF NEAREST-NEIGHBOR DISTANCE AND AGGREGATION SIZE IN ABALONE POPULATIONS: EVIDENCE FOR ALLEE EFFECTS
1 – Scripps Institution of Oceanography, University of California San Diego, 2 – California Department of Fish and Wildlife, 3 – Bodega Marine Laboratory, University of California Davis
Abalone are free-spawning benthic invertebrates whose populations may be subject to Allee Effects, impacting reproduction at low density. The challenge for recovery is to determine if critical thresholds exist in population densities below which reproduction is negatively impacted. Determining the density-dependence of aggregation characteristics aids in identifying critical thresholds for management and conservation. We investigated the density-dependence of nearest-neighbor distances and aggregation sizes with three abalone species: red (Haliotis rufescens), pink (H. corrugata), and northern abalone (H. kamtschatkana). The surveyed populations spanned a broad range of population densities (0.01 – 1.1 abalone m-2). We found that the density-dependence of nearest-neighbor distance is non-linear, increasing rapidly at low densities, negatively impacting fertilization potential. Aggregation size decreases linearly with density decreases, but can impact potential mating success (probability of a mixed-gender aggregation) in a non-linear manner. For aggregations sizes < 4, the probability of mixed-gender aggregations drops precipitously. We identify a critical density threshold of 0.1-0.19 abalone m-2based on the density-dependent reproductive potential estimates obtained from aggregation-level characteristics. These results suggest that the low density thresholds used for abalone management (California Department of Fish and Wildlife) and conservation (NOAA Recovery Plans) are appropriate and precautionary.
† Cerny-Chipman, E.B.*, Menge,B.A.
BROAD SCALE PATTERNS OF PREDATION IN CONGENERIC ROCKY INTERTIDAL WHELKS
Oregon State University
Predator-prey interactions can be strong determinants of community structure, but they can also vary spatially as predators and prey exhibit differing responses to environmental conditions. In rocky intertidal communities, whelks are a primary mid-zone predator whose effects can be sensitive to abiotic factors. Using caged predator enclosures of two intertidal whelks, we tested variation in survival of mussels at 6 sites spanning 170 km along the Oregon coast. We asked whether, 1) predation varied across sites with differing oceanographic regimes, and 2) whelk species influenced patterns of predation across sites. Because broad scale oceanographic conditions differ across study sites, we expected to see site- and species-level differences in the survival of mussel prey. Using mixed effects models, we assessed how cape, site, whelk species, and monitoring date affected the survival of experimental mussels. Results indicate that whelk species, site, monitoring date and an interaction between date and species best explain mussel survival, suggesting that predation differed across sites and that the effect of the whelk congeners changed over time. Overall, results are consistent with the hypothesis that predation variation across sites and species may arise from both environmental context and differences in physiological tolerances of congeneric predators.
† Cheng, B.S.1, Bible, J.M.1, Chang, A.2, Ferner, M.C.2, Wasson, K.3, Zabin, C.J.4, Latta, M.5, Deck, A.2, Grosholz, E.D.1,4
CURRENT ENVIRONMENTAL STRESS CAN OUTWEIGH CLIMATE CHANGE STRESSORS
1 – Bodega Marine Laboratory, University of California, 2 – San Francisco Bay National Estuarine Research Reserve, 3 – Elkhorn Slough National Estuarine Research Reserve, 4 – Environmental Science and Policy, University of California, Davis, 5 – California State Coastal Conservancy
Global change and its effects on the world’s biota have become the focus of a large body of research and there is increasing recognition that multiple environmental stressors may operate in conjunction to produce synergistic or antagonistic interactions. However, few studies have evaluated multiple stressor effects over time scales relevant to the focal organism. We manipulated stressors across life stages of the Olympia oyster (Ostrea lurida), a species of restoration concern along the U.S. west coast using field data from central California estuaries and exposed oysters to simultaneous stressors (warming x hypoxia) and a latent stressor (low salinity). Contrary to expectations, we found additive and opposing effects of warming and hypoxia on oysters. Warming above typical field temperatures increased growth by 28%, whereas hypoxia decreased growth by up to 61%. Surprisingly, we found no synergistic interaction between warming and hypoxia. Oysters were able to partially recover from warming and hypoxia after 12 weeks of benign conditions but treatment groups were still statistically distinguishable. Finally, we found that low salinity exposure resulted in high oyster mortality, but this was not related to stressor exposure during early life history. Based on field data, this work suggests that hypoxia is the most relevant tested stressor for oyster ecology.
† Chiquillo, K.L.1*, Ebert, D.A.2, Slager, C.J.3, Crow, K.D.1
THE SECRET OF THE MERMAID’S PURSE: PHYLOGENETC AFFINITIES WITHIN THE RAJIDAE AND THE EVOLUTION OF A NOVEL REPRODUCTIVE STRATEGY
1 – San Francisco State University, Department of Biology, 2 – Pacific Shark Research Center, Moss Landing Marine Laboratories, 3 – Aquarium of the Bay, San Francisco
The systematics of the skates in the family Rajidae have been contentious for over 250 years, with most studies inferring relationships among geographically clustered species, and non-overlapping taxa and data sets. Rajid skates are oviparous, and lay egg capsules with a single embryo. However, two species exhibit a derived form of egg laying, with multiple embryos per egg capsule. We provide a molecular assessment of the phylogenetic relationships of skates within the family Rajidae based on three mitochondrial genes. The resulting topology supports monophyly the family. However the genus Raja is polyphyletic, and several species assemblages need to be renamed. We proposed a new assemblage as the Rostrorajini, which organizes Rajid species into three well-supported tribal lineages for the first time. Further, these data provide an independent assessment of monophyly for the two species exhibiting multiple embryos per egg capsule, supporting their status as the unique genus Beringraja. We find that among the different size classes of egg capsules, ranging from 1-8 embryos per capsule in this genus, there is variation in frequency and survivorship. In Beringraja binoculata, the strategy of having two embryos per egg capsule occurs in the highest frequency and has the highest survivorship.
Claisse, J.T.1*, Pondella, D.J.1,Love, M.2, Zahn, L.A.1, Williams. C.M.1, Williams J.P.1, Bull, A.S.3
FISH PRODUCTION OF ARTIFICIAL AND NATURAL REEFS OFF THE COAST OF CALIFORNIA
1 – Vantuna Research Group, Occidental College, 2 – University of California, Santa Barbara, 3 – Bureau of Ocean Energy Management
To investigate the conservation and fisheries value of active and decommissioned oil platforms, standing stock biomass and production of fishes on oil platforms and natural rocky reefs off of southern California, USA were modeled using fisheries independent empirically-collected submersible and scuba survey data. All platforms and natural reefs included in the study were surveyed for at least 5 years. Standing stock biomass estimates incorporated depth-specific fish density and size structure with published weight-length relationships. Production of these fishes was then modeled over one year using von Bertalanffy growth function parameters and size-based species-specific estimates of natural mortality. Our results and a review of the literature show that oil platforms off the coast of California have the highest secondary fish production of any marine habitat that has been studied, about an order of magnitude higher than fish communities from other marine ecosystems. These results indicate that the potential contribution of oil platform habitat to biological resources in this region is substantial.
Clary, L.M.*, Smith, K.L., Kuhnz, L.A., Huffard, C.L.
Deep Sea Holothuroid Responses to Food Fluctuations
Monterey Bay Aquarium Research Institute
Deep sea communities are dependent upon surface primary production for food. However, there is little information on population characteristics (density, size distribution, and biomass) of animals in these communities, how these factors change over time, and responses to food fluctuations. This study uses a six-year subset of a 24-year time series project at Station M (~ 4000 m deep, location 220 km off central coast of California) to determine the size distribution and density of holothuroids, an abundant phylogenic class in the deep sea. Length measurements were collected from ROV video transects using open-source video annotation software created at the Monterey Bay Aquarium Research Institute. These data were converted into a biomass estimate using specimen-generated length-mass equations. This study documented changes in the density, size distribution, and resulting biomass for 8 of the 13 holothurian species observed. Changes were observed after an initial influx of particulate organic carbon in June 2007. The overall community biomass increased from negligible in 2006 and 2007 sampling periods to 2 orders of magnitude higher in subsequent sampling periods, peaking in May 2011 (0.14 kg/m2). Although a gap in sampling in 2008 prevent us from attributing the observed changes directly to the influx of food, these results suggest that some species respond more rapidly to large pulses of food than to the more consistent but smaller supply of marine snow.
† Clerkin, P.J.1*, Ebert, D.A.1, Naylor, G.J.P.2
REPRODUCTIVE BIOLOGY AND MATURITY OF DEEP-SEA SHARKS IN THE SOUTHERN INDIAN OCEAN
1 – Moss Landing Marine Laboratories, 2 – College of Charleston
Examination of bycatch from Southern Indian Ocean seamounts: 1) surveyed chondrichthyan fauna, 2) assessed life history characteristics of regional elasmobranch, and 3) contributed to DNA-based chondrichthyan phylogeny as part of the Tree of Life project. Reproductive and maturity data including sex, length, maturity stage, oviducal gland development, egg width, and egg numbers were recorded and analyzed from 2,400 chondrichthyans collected during a 2-month deployment aboard a trawler southeast of Madagascar. Approximately 400 specimens of the genera Centrophorus, Deania, Centroscymnus, Centroselachus, Proscymnodon, Zameus, Etmopterus, Dalatias, Apristurus, Parmaturus, Pseudotriakis, Hydrolagus, and Chimaera were collected from 500 m–1,500 m depths. Over 700 tissue samples for DNA studies and 225 vertebrae and spines for age/growth studies were collected. Qualitative diet data was recorded from sharks including poorly known species, e.g., Proscymnodon plunketi and Pseudotriakis microdon, and several undescribed species of Etmopterus, Apristurus, Parmaturus, Hydrolagus, and Chimaera. Project specimens were deposited at the American Museum of Natural History, the California Academy of Sciences, and the Smithsonian Institution. The expedition was an international collaboration between Moss Landing Marine Laboratories, College of Charleston, Southern Indian Ocean Deepsea Fishers Association, Sealord Corporation, Mauritius Ministry of Fisheries, and was funded, in part, by NSF grant: DEB-01132229.
Cole, J.L.*, Litvin, S.Y., Micheli, F.
DETERMINING TROPHIC LINKAGES IN MACROCYSTIS HOLDFAST COMMUNITIES IN THE LOVERS POINT STATE MARINE RESERVE
The holdfasts Macrocystis pyrifera are an important biogenic habitat, functioning both as a habitat and a food source to a wide variety of marine organisms in nearshore ecosystems. However, previous studies have demonstrated that sediment organic matter (SOM) residing in the holdfast may be the primary food resources for the organisms residing in these habitats, rather than the kelp holdfast itself. We utilized stable isotope analysis to characterize the importance of food resources for invertebrates residing within kelp holdfasts (Macrocystis pyrifera), and to determine how species-specific feeding ecology and kelp density mediate the relative importance of these producers. Macrocystis pyrifera holdfast δ13C values varied between sites within interior and the seaward edge of kelp stands (-12.87‰ v. -11.57‰), but not SOM residing in the holdfast (mean -15.37‰). Invertebrates, such as holothuroids, nemerteans and gastropods showed clear differences in isotopic signature between interior and edge sites (mean δ13C -14.16‰ v. -16.60‰, -15.11‰ v. -16.81‰ and -13.62‰ v. -15.20‰ respectively). Differences in isotopic signatures among sites and species likely derive from the changes in the bioavailability of organic matter among sites coupled with the differences in feeding ecology among species.
FINDING INSPIRATION IN NATURE
Monterey Bay Aquarium Research Institute (MBARI)
Why don’t more students leap into natural history studies? Most probably don’t see an opportunity or think it’s less risky to read a textbook or take a laboratory course. But given the chance, students from elementary school through graduate school find inspiration getting out into nature. Why not make them observe and think for themselves? Don’t answer every question. Exhort them to get dirty or cold and wet. Enhance their sense of discovery by making them part of the environment. With marine botany students, I’ve wallowed in tide pools and snorkeled in kelp forests. Each student chose “a weed” to study and developed a personal, creative format to inform the rest of us about that species. Nature inspired some delicious originality: a Phyllospadix puppet show, poetry, photomicrographs, videos of wriggling zoospores, life history animations, and watercolor art. We etched wine glasses with seaweed shapes and ate California rolls wrapped in Porphyra. Students came early to lab and stayed late to help each other prepare for the final symposium. Each gave a short, nervous lecture to the local community and−truly their enduring contribution−developed a seaweed website. Out in tidepools, parks, school grounds, and gardens, nature is out there waiting to inspire.
† Crafton, R.E.1*, Rius, M.2
DISTRIBUTION MODELING USING MAXIMUM ENTROPY APPROACH AND OPEN ACCESS BIODIVERSITY DATA: A CASE STUDY OF 31 ASCIDIAN SPECIES
1 – University of California Davis, 2 – University of Southampton
While understanding species’ distributions and niches has historically been a central tenant of ecological research, improvements in computational technologies, software creation, and data availability have increased focus on these topics over the last two decades. Species distribution models are used to inform academic understanding of what influences range limits and management and conservation activities regarding climate change and invasive species, among many other topics. However, there are both benefits and concerns in utilizing these resources. To illustrate the power and potential dangers of using freely available modeling packages (in this case Maximum Entropy Modeling Software – Maxent) and open access species occurrence data sets (Global Biodiversity Information Facility and literature review), results for global distribution models for 31 ascidian (Phylum Chordata, Class Ascidiacea) species are presented. Results for both current distributions and modeled plausible distributions are compared to identify areas that are modeled as suitable yet lack reported occurrence records. Global port locations are used as a proxy to identify areas with potentially higher propagule pressure, which when combined with habitat suitability, can be used to illustrate invasion risk. The potential for geographic bias based on data sampling is also considered.
† Cramer, A.N.1*, Lindholm, J.1, Braddock, A.M.1, Katz, S.2
DISTRIBUTION AND ABUNDANCE OF SELECTED CORALS AND SPONGES IN THE CHANNEL ISLANDS NATIONAL MARINE SANCTUARY AS DETERMINED FROM ROV VIDEO IMAGERY
1 – Institute for Applied Marine Ecology at CSU Monterey Bay, 2 – Channel Islands National Marine Sanctuary
Deep, cold-water corals and sponges are threatened around the world in every habitat in which they are known to occur. Their importance is well-established both as a vital component of marine biological diversity and as habitat for demersal fishes and invertebrates. Despite this importance, much remains to be understood regarding their distribution and abundance. In this study we used a remotely operated vehicle (ROV) to explore potential coral and sponge habitats in the vicinity of the Channel Islands National Marine Sanctuary (CINMS). In June 2013, a total of 41.2 hours of ROV video imagery (including both forward- and down-looking) was collected from 9 transects ranging in water depths from 112 m to 624 m. Data on sponges, as well as hard and soft corals, extracted from the video imagery were separated into morphological categories based on genera and size. The substrate and habitat relief associated with each organism was also quantified. Results indicated that while the habitat associations of both groups were largely as predicted, hard corals showed a strong association with hard substrates in predominantly depositional environments.
Cramer, K.L.1*, Norris, R.D.2, O’Dea, A.3
HISTORICAL CHANGE IN CARIBBEAN REEF FISH AND CORAL COMMUNITIES
1 – Smithsonian Institution, 2 – Scripps Institution of Oceanography, University of California San Diego, 3 – Smithsonian Tropical Research Institute
Caribbean reef corals have declined dramatically since the 1980s from coral bleaching and disease outbreaks related to climate change and algal overgrowth related to overfishing. However, paleoecological data from Caribbean Panama revealed that declines in coral and mollusk communities occurred at least decades before coral bleaching and disease, implicating historical land clearing and fishing. The extent of earlier degradation remains unresolved due to the lack of an ecological baseline for Caribbean reefs from the deeper historical past. We have recently implemented a coring study in Caribbean Panama and Belize to track anthropogenic changes in reef fish and benthic communities over the past millennium from analysis of a suite of reef fossil groups preserved in reef sediments. Historical trends in the abundance and composition of corals and reef fishes were assessed from coral skeletal fragments and fish teeth/bones, respectively. Preliminary results from a sediment core from a lagoonal reef in Caribbean Panama reveal an overall decline in coral content and a shift in the trophic structure of the reef fish community based on changes in dominant tooth morphotypes. Ongoing analyses of additional benthic fossil groups and radiometric dating of core material will provide a more detailed reconstruction of change.
Crandall, E.D.1*, Bellinger, M.R.2, Bates, S.J.3, Minch, J.2, Lawson, P.W.4, Sylvia, G.2, Garza, J.C.1
SPATIALLY EXPLICIT MODELS OF CHINOOK SALMON IN THE CALIFORNIA CURRENT REVEAL DISTINCT MARINE DISTRIBUTIONS AMONG STOCKS
1 – Southwest Fisheries Science Center, 2 – Hatfield Marine Science Center, 3 – California Salmon Council, 4 – Northwest Fisheries Science Center
Information about the stock distributions of coastal and pelagic marine fishes is important for successful management of fisheries, as well as for illuminating the ecology and evolution of these organisms. Because their anadromous life-history and natal-homing create stocks that are genetically distinct, salmon of the genus Oncorhynchus provide an opportunity to use genetic assignment methods to understand their distributions on a stock-specific basis. Over the 2010 – 2012 fishing seasons, we obtained GPS coordinates together with SNP or microsatellite genotypes for 26,250 adult Chinook salmon (Oncorhynchus tshawytscha), and assigned each fish to their stock of origin. Maximum-entropy stock distribution models for 12 stocks reveal significant differences in the spatial distribution of most Chinook stocks (as measured by Warren’s I). Four stocks originating between Cape Mendocino and Cape Blanco have probability maxima to the south of their natal river mouth. Moreover, these stocks, together with most stocks from the Columbia River, show distinct responses to bathymetry, with clear probability maxima for bottom depths between 200-500 meters. Reasons for these distinctive spatial patterns are unclear, but might reflect different feeding strategies. Our results imply that Chinook stocks may be fished selectively, decreasing pressure on weak stocks by restricting fishing to certain depths.
Crane, N.L.1,2*, Nelson, P.3,Paddack, M.J.1,4, Bernardi, G.5, Abelson, A.7, Precoda, K1, Cannon, S5
Ecological and sociological impacts of establishing locally managed marine areas with outer island communities of ulithi atoll, Fsm
1 – Oceanic Society, 2 – Cabrillo College, 3 – CFR-West, 4 – Santa Barbara City College, 5 – University of California Santa Cruz, 6 – Tel Aviv University
We present initial results from our work with autonomously governed outer island communities of Yap state, Federated States of Micronesia. These communities are on the front lines of ecological and cultural changes, and are facing declines in critical reef resources. Our work focuses on the inhabited islands of Ulithi Atoll, the fourth largest atoll in the world. Declining coral cover, problematic fishing practices, historical reef degradation and ‘invasive’ species are contributing to a decline in reef health and associated resources. The people of Ulithi rely on their reefs for food and protection from erosion, and the issues they face are ecological and cultural in nature. The traditional approaches to conservation and management were successful, and we present our approach to combining traditional methods with modern scientific analysis to implement management plans. The reefs in the area showed signs of decline between 2011 and 2013, but the reefs on which management was implemented showed signs of management effectiveness. We will present our ecological and socio-cultural findings around the established LMMA’s, and future directions for expansion of management planning throughout a region uniquely suited to implementing such plans.
† Crear, D.P.1*, Lawson, D.2, Seminoff, J.A.3, Eguchi, T.3, LeRoux, R.A.3, Lowe, C.G.1
MOVEMENT PATTERNS AND HABITAT SELECTION OF GREEN SEA TURTLES (CHELONIA MYDAS) WITHIN ANTHROPOGENICALLY-ALTERED WATER TEMPERATURES
1 – California State University Long Beach, 2 – Southwest Regional Office, National Marine Fisheries Service, 3 – Southwest Fisheries Science Center, National Marine Fisheries
Anthropogenic influence of coastal thermal conditions has the potential to affect behavior of the endangered East Pacific green sea turtle (Chelonia mydas; GST), allowing them to occupy their most northern range year-round. It is hypothesized that warm water effluent from coastal power plants along the San Gabriel River, Long Beach, CA and shallow ponds within Anaheim Bay Estuary, Seal Beach, CA, have created a suitable habitat for GSTs. Due to power plant effluent, temperatures within the river have varied up to 20°C in one month, ultimately affecting GST movements. To date, 15 GSTs have been tracked using passive acoustic telemetry. Juveniles have been present year-round in the river, whereas GSTs present in the estuary during summer months eventually moved into the river by winter. Average weekly presence was highest in the warmest zone of the river during both summer (26.1°C) and winter (18.0°C). Water temperature and location in the river explained 51% of variability in turtle presence, whereas location alone only explained 28% of variability in presence, suggesting temperature has a strong influence on turtle movement and distribution. Preliminary data suggests that the river may act as a thermal refuge for GSTs, allowing them to inhabit this area year-round.
† Davis, A.C.D.*, Hixon, M.A.
EFFECTS OF HABITAT ON THE FORAGING RANGE AND BEHAVIOR OF INVASIVE RED LIONFISH (PTEROIS VOLITANS) IN THE BAHAMAS
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. Field experiments have documented that lionfish have decimated populations of many native fishes in native reef systems. However, research to date has not examined within-habitat distributions of lionfish across the reef and how local microhabitat use may affect the foraging patterns of lionfish, and in turn, the within-reef distribution of native prey fishes. I investigated fish-habitat interactions in lionfish and their prey to determine where specifically lionfish are having the greatest effects on prey species. I quantified habitat complexity on multiple invaded reefs to determine relative microhabitat use by lionfish and their prey. Preliminary results show that lionfish forage uniformly across the reef, regardless of habitat type. Because of this, differences in prey abundances may be a result of prey habitat availability and refuge space.
Dawson, M.N*, Schiebelhut, L.M.
DISPERSAL SYNDROMES, ENVIRONMENTAL FILTERS, AND THE GENETIC STRUCTURE OF MARINE POPULATIONS
University of California Merced
Empirical comparisons of marine species indicate that complex life-history traits related to dispersal – such as fecundity and pelagic duration – and population size influence phylogeographic structure in ways that approximate theoretical predictions. However, the effect sizes of these (and other) characteristics of organisms or populations, their impact relative to environmental filters, and interactions between organismal, population, and environmental factors require further clarification; the frequency and impact of deviations from the assumptions of equilibrium theory also are too poorly understood. We explore these issues and suggest that characterizing correlations among life-history traits (‘dispersal syndromes’) and among environmental variables (‘filters’) can provide opportunities for simplifying study design and identifying situations to tease apart the effects of otherwise confounding factors.
† de Nesnera, K.L.*, Anderson, L.M.
The ecosystem engineer Mytilus californianus and its role in the recovery of rocky intertidal communities
University of California Santa Cruz
Ecosystem engineers maintain, modify, or create habitat by altering the biotic and/or abiotic state around them. This ability to regulate the abiotic environment has prompted researchers to recommend incorporating ecosystem engineers into restoration efforts. However, predicting when and where the use of ecosystem engineers will benefit restoration remains a challenge for research. In this study, we tested the ability of the mussel Mytilus californianus to speed up the recovery and/or alter the recovery trajectory of mussel bed communities in central California. We used a randomized block design at two sites along the coast of Vandenberg Air Force Base to compare the recovery of cleared plots (50 x 50 cm) with and without transplanted adult mussels (M. californianus) back to a control state (i.e. natural mussel bed). Plots were sampled at regular intervals between January 2010 and July 2013 to estimate percent cover of species. We found at both sites the presence of mussel transplants jumpstarted recovery and at one site community composition within transplant plots has converged on the control state. Cleared plots at both sites without mussel transplants have not recovered at this date. These results suggest incorporating M. californianus will likely benefit rocky intertidal restoration strategies.
Demes, K.W.*, Salomon, A.K., Keeling, B., Burt, J.
Detecting Tipping Points in Northern Latitude Kelp Forests
Simon Fraser University
Despite their profound and prolonged ecological and societal consequences, phase shifts are notoriously difficult to anticipate. For example, although the cascading effects of sea otters are well known to trigger kelp forest phase shifts, our ability to predict when and where these shifts will occur is limited by context-dependent species-interactions, varying thresholds (i.e. tipping points) and poorly known stabilizing mechanisms (i.e. internal feedbacks). To illuminate these gaps in our knowledge, we sampled benthic reef communities at 20 sites along a gradient in sea otter occupation time (0-25 years) and abundance along the Central Coast of British Columbia. This space for time substitution reveals a strong alteration of ecosystem organization and dynamics. Using information theoretics and a model selection approach, we quantified the strength of evidence for thresholds in kelp forest dynamics driven by the top-down, cascading impacts of sea otter range expansion and the degree to which these dynamics are mediated by context-dependent effects (i.e. wave exposure, rugosity, regional oceanography). Ecological surprises are an inevitable feature of all ecosystems, however, by studying their dynamics we may extract useful lessons to better plan for their future possibility more broadly.
Dilly, G.F.*, Nguyen, A.T., Rivest, E.B., Kapsenberg, L., Kelly, M.W., Hofmann, G.E.
COMPARATIVE MUSSEL RESPIROMETRY DURING SIMULATED UPWELLING EVENTS USING ACIDIFICATION RESPIROMETRY CHAMBERS (ARCs)
University of California Santa Barbara
As an upwelling region that experiences episodically high levels of pCO2, the US west coast may be particularly impacted by ocean acidification. The biological consequences of this are currently being addressed by the Ocean Margin Ecosystem Group for Acidification Studies (OMEGAS) research consortiumhttp://omegas.science.oregonstate.edu/. OMEGAS integrates oceanographic and biological processes at sites in Oregon and California. At UCSB, we have designed, designed, developed, and utilized two multi-sample experimentation apparatus named the Acidification Respirometry Chambers (ARCs) to measure the effects of upwelling events on invertebrates from each site. The ARCs enable comparative respirometric measurements of mussels to simulated Oregon and California upwelling events. Each ARC is built from a solid aluminum block and houses six closed batch vessels; flow-through tubing circulates water from an external chiller, maintaining even temperature. Internal mixing is achieved using small external stirrers coupled with internal stir bars. Respirometric rate is measured using a fiber-optic O2 probe and oxygen sensing spots inside optically-clear sealed vessels. Using a CO2 gas-mixing system, we simulated four relevant ocean conditions based on oceanographic data (CA Relaxed – 18°C, 300 pCO2; CA Upwelling – 12°C, 650 pCO2;OR Relaxed – 14°C, 300 pCO2; OR Upwelling – 8°C, 1200 pCO2). Results will be discussed.
† Donovan, M.K.1*, Friedlander, A.M.1, Stamoulis, K.1, DeMartini, E.E.2, Williams, I.D.2
SPATIAL PATTERNS OF FISH ASSEMBLAGE STRUCTURE IN THE HAWAIIAN ISLANDS: INDENTIFYING BIOGEOGRAPHIC PATTERNS AND SPECIES AFFINITIES
1 – Biology Department, University of Hawaii at Manoa, 2 – NOAA Pacific Islands Fisheries Science Center
This study synthesized underwater-visual survey data into a spatially comprehensive characterization of reef fish assemblages around the Hawaiian Islands allowing us to define the distribution of fishes across the entire Hawaiian Archipelago. With this robust data set, we developed a biogeographic framework to examine natural and anthropogenic factors that influenced patterns of reef fish assemblage structure across one of the most unique and isolated marine ecosystems on earth. We combined the observational data with information on each species’ life history traits and known geographic distributions to develop hypotheses about spatial patterns of abundance and biomass along latitudinal, oceanographic and anthropogenic gradients. Despite high levels of exploitation of fishes in the Main Hawaiian Islands (MHI) compared to the isolated and uninhabited, Northwestern Hawaiian Islands (NWHI), the MHI today has a higher richness of fishes and higher levels of endemism than the NWHI. This pattern among others was explored following a rigorous quantitative approach, with analyses covering various metrics (e.g. numerical density, biomass, trophic structure) bringing in concepts from biogeography theory. Regional affinities of species within the archipelago were in concordance with the known geographic distributions and hypothesized dispersal of each species to Hawaii. This work serves to identify important faunal breaks and spatial patterns of fish assemblage structure across the archipelago that will help to define regional management strategies in Hawaii.
Dudgeon, S.R.*, Kübler, J.E.
MODELS PREDICTING EFFECTS OF OCEAN ACIDIFICATION ON PRODUCTIVITY OF CO2-USING AND BICARBONATE-USING SEAWEEDS
California State University, Northridge
The negative effects of changing ocean chemistry are documented for many calcareous species. Here, we estimate the effects of ocean acidification (OA) on noncalcifying macroalgae, based on the mechanisms of inorganic nutrient uptake and available data for photosynthetic and growth rate effects of changing dissolved inorganic carbon concentration [DIC]. Our analyses predict two groups of seaweeds that are likely to have enhanced productivity under OA. The mechanisms of enhancement for the 2 groups differ. First, non-bicarbonate using species have no mechanism of active uptake of dissolved inorganic carbon. Those species are predicted to increase productivity via direct alleviation of inorganic carbon limitation up to a 50% increase in photosynthesis as pCO2 rises from 400 to 460 µatm. Increased pCO2 will enhance productivity primarily at cooler temperatures (<15°C) and in light-saturated environments. In contrast, algal species with inducible inorganic carbon-concentrating mechanisms of the well described, Ulva type, are predicted to have enhanced growth without enhanced photosynthesis under OA via an indirect energetic benefit of elevated [DIC] progressively downregulating two modes of active uptake of bicarbonate. Changes in physiological performances of macroalgae may affect their ecology and the composition of ecosystems via enhancements of net productivity even without changes in photosynthetic rate.
IS ACCLIMATION BENEFICIAL TO SCLERACTINIANS CORALS?
California State University, Northridge
With coral reefs exposed to the effects of climate change, attention is turning to the extent to which scleractinians can acclimatize to the new physical condition. The implicit assumption in this approach – that acclimatization is beneficial – has not been tested, even though it has been investigated in other systems in the form of the beneficial acclimation hypothesis (BAH). This study tests BAH for a coral, using two experiments in which massive Porites was acclimated to three temperatures for 15-21 d and then transferred to each of the same temperatures for a treatment period of 15 d. The response of the host was measured as calcification, the response of the symbiont as maximum photochemical efficiency, and ANOVA with polynomial contrasts used to distinguish among BAH and four alternative hypotheses describing the consequences of acclimation. Support for BAH was equivocal, but was stronger for the host than the symbioints; OAT (optimal acclimation temperature) also was supported, but more strongly for the symbiont than the host, and CIB (cooler is better) was supported for the symbionts. These results suggest that acclimation is not always beneficial for corals, and they reveal how dynamic acclimation to variable thermal regimes could modulate host-symbiont interactions.
Edwards, M.S.1*, Konar, B.K.2
PERSISTENCE OF ALTERNATE STATE BOUNDARIES IN THE COASTAL MARINE ECOSYSTEM OF THE ALEUTIAN ARCHIPELAGO
1 – San Diego State University, 2 – University of Alaska Fairbanks
Kelp forests and urchin barrens are alternate states of community composition that often exist adjacent to one another in temperate marine ecosystems. This study explored the spatial persistence of kelp forest-urchin barren boundaries in the Aleutian Archipelago following the decline in sea otter populations. One-week and two-year long experiments were done to examine 1) if the boundaries between forests and barrens occur across a broad (800 km) spatial scale, 2) if they persist in the same location across years, and 3) how spatially general are biological mechanisms that influence sea urchin behavior at these boundaries. Kelp forest-urchin barren boundaries, found across our study area, persisted in the same location for the one to two years. Urchins moved into kelp forests and persisted for one to two years after all algae were cleared but would not invade kelp forests when 25% or more of the substrate was left covered in kelp. Together, these data show that kelp forest-urchin barren boundaries are spatially stable for at least two years and are maintained by physical abrasion of the seafloor by the kelps, but when the kelps are lost or reduced in abundance, the urchins can invade the forest and extend the barren areas.
Eernisse, D.J.1*, Pittman, C.2, Pilgrim, E.M.3
SIPHONARIA PROGRESS GOES “BOINK”: HAWAII’S ONLY RECOGNIZED SPECIES IS INSTEAD THREE SEPARATE CLADES
1 – Cal State Fullerton, 2 – Fairfield, WA, 3 – Ecol. Exposure Res. Div., US EPA,
Native Hawaiians call siphon limpets (Siphonariidae) ‘opihi ‘awa, which means bitter tasting ‘opihi. Although not edible, like true ‘opihi (true limpets), they are said to have used ‘opihi ‘awa for medicine and sorcery. After Siphonaria normalis Gould 1846 was formally described, some additional variety names were proposed, but recent authors have reverted to treating all Hawaiian siphon limpets as a single variable species, S. normalis. This name has also been used for other islands in the West Pacific, implyingS. normalis is widespread. It was thus a surprise to find that Hawaiian Siphonaria are comprised of at least three independent clades, as estimated from our preliminary phylogenetic analysis based on mitochondrial 16S and COI sequences. This included siphon limpets from three Hawaiian islands and all other available 16S or COI Siphonariidae sequences. The most common of these clades also has rather dramatic sequence differences within and between most of our Maui, Oʻahu, and Kauaʻi localities, perhaps implying that a planktonic larval stage is lacking for at least this clade. This phylogeographic structure, or perhaps even evidence of a cryptic species complex, also implies that a genuine Hawaiian radiation has occurred in parallel with those of better-studied endemic taxa, including ‘opihi.
Elsberry, L.A.*, Burnaford, J.L.
THE REGIONAL AND SEASONAL RESPONSE OF A HIGH INTERTIDAL ALGA TO LOW TIDE CONDITIONS
California State University, Fullerton
The high intertidal alga Endocladia muricata is found from Alaska to Baja California, and regional populations experience different low tide conditions that vary by season. We determined the photosynthetic recovery of Endocladia from Washington and southern California following exposure to low tide conditions. We collected individuals from the high and low edges of Endocladia’s tidal distribution in each region and exposed them to simulated low tide treatments for 1 or 4 hours. Treatments were fully factorial with two hydration levels (100 and ~50%) and three temperatures (winter=10oC, 20oC, 30oC; summer=20oC, 30oC, 40oC). Completeness and rate of recovery varied by season and region and was affected by temperature, desiccation state, and length of emersion time. High edge individuals frequently recovered more completely than low edge individuals and individuals in low temperature treatments regularly showed elevated recovery relative to individuals in high temperature treatments. Recovery of individuals after 4 hr of low tide exposure was reduced relative to the recovery of individuals experiencing a shorter low tide in both seasons and regions. The photosynthetic response of Endocladiato low tide conditions varies seasonally and by region indicating that the response of this alga to rising temperatures may differ throughout its geographic range.
NAVIGATING THE COASTAL COMMISSION PERMITTING PROCESS; PAST, CURRENT, AND FUTURE ARTIFICIAL REEF PROJECTS
California Coastal Commission
Obtaining a coastal development permit (CDP) can be a time-consuming, difficult, and frustrating endeavor. Commission Staff Ecologist, Dr. Jonna Engel, will discuss how to plan for and streamline the environmental review and permitting process. She will cover permit requirements, key issues, what the Commission looks for, constraints to think about, and pitfalls and challenges that can hinder the process. Dr. Engel will highlight specific topics and concerns pertinent to artificial reefs using past and current projects as examples.
Erisman, B.E.1*, Apel, A.A.2, MacCall, A.3, Román-Rodríguez, M.J.4, Fujita, R.2
THE INFLUENCE OF GEAR SELECTIVITY AND SPAWNING BEHAVIOR ON A DATA-POOR ASSESSMENT OF A SPAWNING AGGREGATION FISHERY
1 – Scripps Institution of Oceanography, 2 – Environmental Defense Fund, 3 – National Marine Fisheries Service, 4 – Comisión de Ecología y Desarrollo Sustentable del Estado de Sonora
We used several data-poor techniques to investigate the possible effects of gear regulations and age-dependent variation in spawning frequency on assessments of a spawning aggregation fishery for the Gulf corvina (Cynoscion othonopterus) in the Gulf of California, Mexico, during the period of 1998 to 2012. Assessments using length-based metrics suggested that the fishery exceeded biological reference points for sustainability during most years and benefitted from the implementation of a regulation that standardized the mesh size of gill nets used in the fishery. Modeled estimates of spawning potential ratios (SPR) were higher when spawning frequency was assumed to be age invariant and were significantly higher after the implementation of gear regulations. However, SPR values only exceeded targeted references points during the current fishing period under conditions of age invariant spawning frequency. Differences in the conclusions drawn among the various analyses demonstrate the need to incorporate multiple assessment methods in data-poor situations. This study provides further evidence that estimates of reproductive potential are highly sensitive to age dependent variation in spawning frequency, and it suggests that details related to spawning behavior require more attention in stock assessments, particularly for fisheries that target spawning aggregations.
† Evensen, N.R.*, Edmunds P.J.
ALTERED COMPETITIVE INTERACTIONS BETWEEN CORALS IN A HIGH Pco2 ENVIRONMENT
California State University, Northridge
As large amounts of information are becoming available describing the organismic responses of corals to ocean acidification (OA), attention is turning to the effects of OA on ecological processes that determine the community structure. One such process is interspecific competition, and a classic means by which this can be studied is with Lotka-Volterra equations. In this study, we tested the hypothesis that Pco2modulates interspecific competition between corals. Competitive ability was defined by linear extension, with the assumption that the outcome of competition is mediated by the rate at which corals meet and overgrow (or are overgrown by) adjacent corals. Competitive encounters between corals were staged by placing colonies of massive Porites spp. adjacent to (< 5 mm) colonies of Montipora aequituberculata and incubating the pairs at ambient (400 µatm) and elevated (1020 µatm) Pco2 under ecologically relevant conditions of light, flow, and temperature. After 21 d, the extension of M. aequituberculata in interspecific pairs was reduced 32.6%, but growth of massive Porites was unaffected. This outcome reflected a reduction in the competitive coefficient (α) of M. aequituberculata relative to massivePorites. These results are among the first to suggest that OA could affect ecological processes mediating coral community structure.
† Feehan, C.J.*, Scheibling, R.E.
DISEASE AS A CONTROL ON SEA URCHIN POPULATIONS IN NOVA SCOTIAN KELP BEDS
Biology Department, Dalhousie University
In Nova Scotia, Canada, periodic outbreaks of amoebic disease (paramoebiasis) cause mass mortality of sea urchins Strongylocentrotus droebachiensis in the barrens state. However, in kelp beds, where sea urchins are cryptic and generally less dense than in barrens, disease outbreaks are not readily observed and the importance of disease in regulating these populations is unknown. To determine whether sea urchin populations in kelp beds are controlled by disease, we analyzed population data from kelp beds at a single location (St. Margarets Bay) across a span of 44 years (1968–2012) to compare changes in size structure and density in relation to the timing of disease outbreaks in adjacent sea urchin aggregations and barrens. We found that sea urchin density, maximum test diameter and percentage of adults decreased following disease outbreaks and increased during intervening periods without disease, indicating that disease regulates the population in kelp beds by limiting survival to adulthood. Our results suggest that disease has replaced predation as a major agent controlling sea urchin populations in Nova Scotian kelp beds.
† Fennie, H.W.1*, Hamilton, S.L.1, Sogard, S.M.2, Barry, J.P.3
THE EFFECTS OF ELEVATED CO2 ON THE BEHAVIOR AND PHYSIOLOGY OF JUVENILE ROCKFISHES
1 – Moss Landing Marine Laboratories, 2 – NOAA SWFSC, 3 – Monterey Bay Aquarium Research Institute
The rapid increase of anthropogenic carbon dioxide (CO2) emissions to the atmosphere is altering seawater chemistry at an alarming rate. Many studies have shown that elevated dissolved seawater CO2(i.e. pCO2) concentrations and associated decreases in seawater pH will have negative impacts on marine organisms that secrete calcium carbonate structures. Recent research has shown that elevated pCO2affects the behavior and physiology of several tropical and temperate fishes, but some species appear to be resilient to near future pCO2 levels. Here, we investigated the effects of near future pCO2 levels (4 different pH treatments: 7.2, 7.5, 7.8, and 8.0) on two species of juvenile rockfishes (Genus Sebastes) after 2-3 months exposure to treatment conditions. We examined behavioral lateralization (a test of brain functional asymmetry), critical swimming speed, and metabolic rate of Copper (S. caurinus) and Blue Rockfish (S. mystinus), finding species-specific responses to elevated pCO2. Copper Rockfish exhibited shifts in their behavioral lateralization, decreased critical swimming speed, and changes in their aerobic performance when exposed to elevated pCO2, while Blue rockfish appeared more resistant. These findings indicate that climate change may reduce the fitness of some species of temperate reef fish, which could alter the species composition of California’s kelp forests in the future.
† Fernández, R.G.*, Ladah, L.B.
CRAB MEGALOPAE SETTLLEMENT AND PHYSICAL CONDITIONS IN THE WATER COLUMN
Department of Biological Oceanography, CICESE
Crabs have complex life cycles, ranging from a planktonic larval phase to a benthic adult. Wind and tidal forcing may facilitate the migration of crab larvae from continental shelf waters to the coast. These physical factors play an important role in the spatial and temporal variation in crab settlement. In this study, weekly and daily crab megalopae larvae settlement was estimated in the low intertidal. Settlement abundance was correlated to wind stress, tidal range, and internal tidal amplitude. Settlement peaks were found 2 to 3 days after the spring tide on the full moon, suggesting selective tidal stream transport or tidally mediated transport. Implications for future research relating invertebrate larval settlement with water column conditions will be discussed.
† Filbee-Dexter, K.*, Scheibling, R.E.
DETRITAL SUBSIDY FROM KELP BEDS ENHANCES SEA URCHIN REPRODUCTION IN ADJACENT SEDIMENTARY HABITATS IN NOVA SCOTIA
Highly productive kelp beds off Nova Scotia, Canada export large amounts of detrital material to adjacent sedimentary habitats in deeper waters. We evaluated the importance of this subsidy to sea urchinsStrongylocentrotus droebachiensis residing in these less productive habitats. Gonad index and gut content of urchins at 60 m depth were measured at monthly intervals from September 2010 to May 2013 in a large semi-protected bay. Gut contents indicated detrital kelp was the predominant food source for these urchins from March to October. We observed a slightly lower gonad index in deep-living urchins compared to those residing in kelp beds at 10 m depth, but deep urchins spawned twice annually. To evaluate the response of deep urchins to drift algal subsidies, and to estimate the turnover time of this material, we deployed weighted lines baited with kelp fronds at 45 and 60 m depth and measured rates of encounter and consumption of drift-algae by urchins using a towed camera system. Urchins aggregated on the kelp within hours of deployment, and completely consumed it after 1 and 3 months at 45 and 60 m respectively. Our findings suggest detrital kelp represents an important energy source that enhances reproduction of deep-living urchins.
PALOS VERDES KELP FOREST RESTORATION
Bay Restoration Foundation, Center for Santa Monica Bay Studies Loyola Marymount University
The giant kelp, (Macrocystis pyrifera) forest off the Palos Verdes Peninsula has shown losses of 75% in the past 60 years. Numerous stressors are attributed to this loss e.g., pollution, coastal development, sedimentation, and overfishing. In 2010 extensive mapping of the rocky reef complex off of Palos Verdes described 61.5 hectares of urchin barrens where giant kelp canopy had persisted historically. An effort to restore giant kelp and associated biota to these 61.5 hectares of rocky reefs is underway. An estimated 4.8 million purple sea urchins, (Strongylocentrotus purpuratus) will be removed from the environment by hammering in situ. A consortium of professionals and volunteers from environmental groups, public aquaria, academic researchers, and commercial sea urchin harvesters are expected to complete this work in 5 years. Modeling suggests this effort will increase fish biomass on the reefs by 267% and harvestable red urchin, (Strongylocentrotus franciscanus) gonad by 883%. Associated efforts include human use mapping of restored areas and method development for the reestablishment of green abalone, (Halitotis fulgens).
† Fuller, T.L.1*, Tepolt, C.K.2
IDENTIFYING GENES UNDER SELECTION IN THE INVASIVE GREEN CRAB, CARCINUS MAENAS
1 – California State University Monterey Bay, 2 – Hopkins Marine Station
Expected changes in ocean temperatures will likely alter marine ecosystems and there is a large effort to understand how sea creatures will respond to these shifting environments. The invasive European green crab, Carcinus maenas (Linnaeus 1758), is a useful species with which to study organismal adaptation because of its closely monitored worldwide expansion. Previous physiological work concluded different C. maenas populations may be locally adapted to thermal environments. To better understand this adaption, this project examines genes apparently under selection between sites with different thermal conditions. From 7 populations, we identified 11,420 single nucleotide polymorphisms (SNPs), but only 504 SNPs in 315 contiguous sequences appeared as under selection. We chose 6 sequences to investigate further based on them containing at least 3 outlier SNPs, patterns of genetic differentiation, and sequence annotations from most similar model organism Drosophila. These sequences matched genes involved in iron storage, amino acid metabolism, protein degradation, copulation, actin filament regulation, and chromosomal maintenance. We verified these patterns by sequencing several of these genes in an expanded sample set. With these data and the species’ invasion history, we can explore the timescale as well as some the genetic mechanisms for adaptive evolution in C. maenas.
Garcia, D.E.1*, Drazen J.C.2, Weng, K.C.2
ENERGETICS OF THE DEEP-WATER BLUNTNOSE SIXGILL SHARK, HEXANCHUS GRISEUS: ENZYME ACTIVITY AS AN INDICATOR FOR METABOLIC RATE
1 – University of Hawaii, Department of Marine Biology, 2 – University of Hawaii, Department of Oceanography
A trend for metabolic rates within ocean taxa is a general decline with depth. This trend cannot be explained by the metabolic theory of ecology, which correlates metabolic rate to the mass and temperature of an organism. The visual-interaction hypothesis suggests that this trend results from differences in predator-prey interactions, and that species may contradict the metabolic theory of ecology based on ecological strategies. We wished to evaluate these hypotheses for elasmobranchs using enzyme activity as a proxy for metabolic rate. We compared values for Hexanchus griseus, which is believed to be an apex predator in deep-sea ecosystems, with shallow living species. Animals were caught off of Oahu and biopsied for white muscle. To determine enzyme activity assays were conducted on four key metabolic enzymes: Citrate Synthase, Pyruvate Kinase, Lactate Dehydrogenase, and Malate Dehydrogenase. The results indicate a decline in elasmobranch enzyme activity, and therefore metabolic rate, with increasing depth. This suggests that the metabolic theory of ecology may not hold true for elasmobranchs, and that differences in rates, between species of comparable size, may indicate differences in ecological strategies, as proposed by the visual-interaction hypothesis.
† Garland, M.A.1*, Paganini, A.2, Stillman, J.2, Tomanek, L.1
PROTEOMIC ANALYSIS OF PORCELAIN CRAB GILL TISSUE FOLLOWING COMBINED PH, THERMAL, AND EMERSION STRESS
1 – Center for Coastal Marine Sciences, California Polytechnic State University (San Luis Obispo), 2 – Romberg Tiburon Center, San Francisco State University
Crustaceans are an underrepresented class of organisms in climate change studies when compared to other taxa. Consequently, the current scientific literature lacks enough data for consensus on how crustaceans will respond to simultaneous stressors induced by climate change. In the present study, we subject the porcelain crab Petrolisthes cinctipes to multiple simultaneous stressors (temperature, pH, and emersion) at ecologically-relevant conditions over a 2 week period. We characterized the molecular response to both individual and synergistic stress effects by performing an exploratory proteomic analysis on gill tissue. Low pH stress suppresses immune-related proteins and molecular chaperones of the endoplasmic reticulum, reducing glycoprotein secretion. Concurrently, it induces proteins involved in an ammonia excretion mechanism, possibly resulting from cuticle turnover and Notch-mediated apoptosis. Emersion hampers the response to low pH via decreased expression of metabolism and signaling proteins, which may prevent toxic ammonia accumulation in the gills. Adding thermal stress induces expression of an array of serine proteases, including stubble-like and testisin-like proteins sharing homology with prophenoloxidase activating factors. It also induces a CO2-mediating protein, a blood clotting factor, and several F-ATP synthase subunits. Our results indicate that climate change may perturb expression of energy metabolism, signaling, and immune- related proteins in crustaceans.
† Giddens, J.L.1, Friedlander, A.M.1, Conklin, E.2, Wiggins, C.H.2, Stamoulis, K.A.1, Donovan, M.K.1
EXPERIMENTAL REMOVAL OF THE INTRODUCED PREDATOR CEPHALOPHOLIS ARGUS IN PUAKO, HAWAII: METHODS FOR MANAGING MARINE INVASIVE SPECIES
1 – University of Hawai‘i at Manoa – Fisheries Ecology Research Lab, 2 – The Nature Conservancy
Invasive species are a concern for marine biodiversity, particularly in Hawai‘i with its large proportion of endemic species. This research focused on the feasibility of removing the introduced grouper, roi (Cephalopholis argus), as a management tool for coral-reef ecosystem restoration. The objectives were to investigate the dynamics of C. argus on 1.2 ha-1 of coral-reef and 1) compare population density estimate methods in order to accurately evaluate abundance 2) estimate population mortality and catchability rates, and 3) quantify the re-colonization rates by mapping distribution and movements in response to a depletion experiment. The number of individuals removed during a fish-down experiment provided a direct measure of the initial population abundance (19.5 ha-1). A Leslie depletion model yielded the most accurate assessment of initial density (-12.7% error) compared to belt transects (+82.3% error) and tow-board census (-69.1% error). Estimates of natural mortality were low (0.0-0.08), and fishing mortality ranged from negligible to 8.0 % yr-1. Roi movement was monitored through a mark and re-capture program. Individuals recolonized the removal area (one roi every 1-2 months). This study engaged the local fishing community in quantifying the feasibility of roi removal as a management tool, and provides methods for controlling marine invasive species.
Gilbane, L.1*, Henkel, S.2, Goldfinger, C.3
THE ROLE OF COLLABORATION IN CONDUCTING A REGIONAL BENTHIC ASSESSMENT
1 – Bureau of Ocean Energy Management, 2 – Hatfield Science Center, 3 – Oregon State University
The process of leasing Federal waters for wave and deep-water wind facilities along the northwest coast of America has begun. Although designs of these facilities are in development, there will be direct and far-field impacts to the seafloor and surrounding benthic organisms. Prior to leasing Federal waters, the Bureau of Ocean Energy Management (BOEM) requires knowledge of seafloor habitats that may be affected and so in 2010, BOEM began a cooperative agreement with Oregon State University to map the surficial geology and sample the benthic biology from northern California to the Canadian border. This was BOEM’s first survey in this region and to be effective over such a large area it was critical to work collaboratively and build upon previous benthic assessments unrelated to energy development. By taking this approach we were able to 1) analyze the surficial geology and biology of six distinct areas and 2) model species-habitat relationships to predict habitat suitability outside the study area. Results from this effort will inform assessments and further surveys needed for renewable energy installations in Federal waters. Taking a collaborative approach provided substantial cost savings and outcomes that benefit all state and Federal agencies involved in regional marine planning.
Gilman, S. E.1*, Hendrix, A.2, Osborn, J.2, Walker, B.2
Effects of aerial exposure on the respiration and digestion of the intertidal barnacle Balanus glandula
1 – Keck Science Department of Claremont McKenna, Scripps, and Pitzer Colleges, 2 – Scripps College
Low tide exposure is generally considered the more stressful phase of intertidal life. During low tide organisms experience increased thermal and desiccation stress and have reduced opportunity for respiration and feeding. But many species are quite successful in high shore habitats, suggesting that terrestrial exposure may present opportunities as well. Greater respiration rates may be possible under the 10-fold greater oxygen leves in air. And while feeding is often limited by low tide, digestion need not be. We examined the effects of aerial exposure on the feeding and respiration of the intertidal barnacleBalanus glandula collected from Newport Bay in southern California. We found that B. glandula respired in air across all temperatures tested (16 – 35°C), but respiration was most frequent at warmer temperatures. Warmer temperatures also induced greater oxygen consumption upon re-submersion, suggesting that aerial respiration cannot fully meet metabolic needs during low tide. Digestion, as measured by the time to produce a fecal pellet, was delayed by aerial exposure at both 16°C and 35°C. This result suggests that barnacles undergo metabolic depression during low tide, regardless of thermal conditions. Overall there was little evidence that aerial exposure augments B. glandula‘s individual performance.
Ginsburg, D.W.*, Collins, L.E., Haw, J.H.
SCIENTIFIC RESEARCH DIVING FOR EXPERIENTIAL LEARNING AND COMMUNICATING ABOUT COASTAL MARINE MANAGEMENT AND POLICY
University of Southern California, Environmental Studies Program
The USC Environmental Studies Program uses experiential learning and mobile technology tools in remote field locations such as the Western Pacific Islands. Undergraduates are trained as scientific divers and travel to Micronesia to study the impacts of development on coastal environments. Students participate in a long-term ecological monitoring project to assess the health of a marine protected area in partnership with the Government of Palau. Unlike teaching within a traditional classroom, experiential learning allows for more learners to be successful by increasing the pedagogical approaches to the material. Students understand topics more fully by actively engaging in a field activity rather than by only reading about a concept. Compared to a traditional course, field programs are conducted over a three-week period. Students develop a research strategy on a given topic and write a technical blog post targeted towards a non-expert audience. In the field, each student is required to not only incorporate the primary literature related to their topic, but also integrate their collective field experience into a short video or reflective blog. Our goal is to help students synthesize information on complex marine environmental issues while also increasing their ability to communicate with both specialized and general audiences.
† Gleason, M.S.1*, Price, N.N.1,Kram, S.L.1, Kelly, E.L.1, Donham, E.2, Hamilton, S.L.2, and Smith, J.E.1
CHANGES IN SETTLEMENT BEHAVIOR OF HALIOTIS RUFESCENS LARVAE AS A CONSEQUENCE OF EXPOSURE TO ACIDIFIED CONDITIONS
1 – Scripps Institution of Oceanography – University of California, San Diego, 2 – Moss Landing Marine Laboratories
Ocean acidification could potentially alter ecologically significant processes, in particular the symbiotic interaction between settling invertebrate larvae and settlement cue producing calcified algae. It is hypothesized that the disruption of settlement arises from impairment of cue detection by larvae. Physiological changes to crustose coralline algae (CCA) as a consequence of increased seawater acidity may also impair successful settlement. Red abalone (Haliotis rufescens) larval settlement experiments were conducted by analyzing the proportion of larvae settled after exposure to CO2-enrichment. CCA (Lithothamnium californicum) were kept in high CO2 conditions (treatment pH 0.2 ± 0.05 units lower than ambient) for 6 weeks. Red abalone larvae were exposed to the same high CO2 treatment during early development. The settlement experiment revealed exposure to enriched-CO2 conditions during larval development significantly reduced settlement on CCA. Survival rates of abalone larvae exposed to acidified treatments were also analyzed; four out of five studies did not reveal significant differences in survival. The impact of ocean acidification on larval sensory capabilities could threaten the survival of invertebrate larvae and the replenishment of abalone populations in the benthic ecosystem.
† Gould, K.G.*, Wilson, P.S.
HOST PLANT USE AFFECTS MATE CHOICE FOR A CHRYSOMELID BEETLE
California State University, Northridge
The development of ecotypes within a species is a primary step in speciation and has been observed in a number of species, particularly among plant-eating insects where a shift in host plant can lead to differentiation between populations. We investigated host plant use in the chrysomelid beetle Trirhabda eriodictyonis, which lives and feeds on two closely related plants: Eriodictyon crassifolium (Ec) andEriodictyon trichocalyx (Et). Because these beetles are often species-specific as to host plant, we asked whether the use of two hosts might reflect cryptic differentiation. We first investigated whether beetles preferred one plant over the other, then looked into whether a beetle’s host plant affected its choice of mate. The beetles preferred feeding on Ec as larvae but switched their preference to Et as adults, regardless of which plant they started life on. Males showed no preference for females based on host plant, attempting to mate in similar numbers with females from both plants. Female behavior was more complicated. Females on Et showed no preference, but females living on Ec significantly preferred to mate with males on Et. We conclude that this beetle has not differentiated into ecotypes.
Green, S.J.1*, Côté, I.M.2
TRAIT-BASED DIET SELECTION: PREY BEHAVIOUR AND MORPHOLOGY PREDICT VULNERABILITY TO PREDATION
1 – Department of Zoology, Oregon State University, 2 – Department of Biological Sciences, Simon Fraser University
Predicting the strength of predatory interactions can provide important insights into community structure and dynamics. However, the set of prey species available to a given predator often varies spatially and temporally, owing increasingly to human-mediated species addition and removal. We propose that predator diet selection could be predicted across prey assemblages if vulnerability to predation is conferred by general morphological and behavioural traits shared by prey species. We investigate the potential for trait-based prey selection using the Indo-Pacific lionfish (Pterois volitans), an invasive predator that is spreading across the Western Atlantic region where it preys on species-rich coral reef fish communities. Accounting for relatedness among taxa, we test whether morphological and behavioural traits of reef fishes predict patterns of predation by lionfish determined from 1) in situ visual observations of prey consumption and availability, and (2) comparisons of prey abundance in stomach contents to availability on invaded reefs. Both analyses reveal that prey size, body shape, position in the water column, and cleaning behaviour are important determinants of prey selection, with small, fusiform fishes that are found just above reefs and exhibit facultative cleaning behaviour most vulnerable. Together, these traits heighten the risk of predation by a factor of nearly 200. As the invasion progresses, native species that exhibit traits vulnerable to predation are likely to post more rapid and substantial population changes. Our study reveals that a trait-based approach to studying diet selection can yield important insights into predator-prey interactions, and could be used across predator species and ecosystems to predict the outcomes changing species assemblages on community dynamics.
† Grupe, B.M.*, Levin, L.A.
METACOMMUNITIES, METHANE SEEPS, AND MACROFAUNAL DIVERSITY
Scripps Institution of Oceanography, University of California San Diego
Patchy communities that are linked by the movement of individuals (e.g. larval dispersal) can be considered in a metacommunity framework, in which factors at both local and regional scales have the ability to influence community assembly and the maintenance of biodiversity. At methane seeps off Oregon and Costa Rica, we deployed substrates (habitat patches) that were colonized over one year. Upon recovery, we quantified the density and diversity of macrofaunal invertebrates to address the following questions: 1) Are metacommunity patterns detectable across distinct environmental gradients at methane seeps? 2) Do particular mechanistic models appear especially relevant to certain microhabitats or taxonomic groups within methane seep ecosystems? Site-by-species incidence matrices suggest that metacommunity structure differs between experimental (early-succession) and natural (late-succession) substrates. By decomposing the total community variation into environmental and spatial components, we can also gain insight into which factors underlie patterns of beta diversity. Finally, ranked abundance plots reveal that metacommunities may behave differently at active seeps versus inactive background sites, and gastropod and polychaete taxa seem to display distinct metacommunity patterns. While we interpret our results in light of deep-sea chemosynthetic ecosystems, we emphasize the applicability of the metacommunity framework to other patchy marine habitats such as coastal headlands, tide pools, or seamounts.
† Harrington, A.M.*, Hovel, K.A.
HABITAT ASSOCIATIONS AND SHELTER USE BEHAVIORS IN THE CALIFORNIA SPINY LOBSTER: MULTI-SCALE ASSESSMENTS ON ROCKY REEFS
Coastal and Marine Institute Laboratory, San Diego State University
The California spiny lobster (Panulirus interruptus) is a gregarious, shelter-dwelling species whose habitat associations likely minimize predation risk while maximizing foraging opportunities. In a collaborative effort, we quantified baseline levels and short-term changes in abundance, size distribution, movement, and behavior of P. interruptus within and outside of newly implemented marine protected areas (MPAs) in the South Coast Region of California. We conducted SCUBA-based transect surveys of rocky reefs at ten sites (five within, five outside of MPAs) to link lobster density and behavior to benthic habitat features at landscape scales. At local scales, we conducted tethering experiments to examine how relative survival of subadults varies under different shelter and social conditions. Lobster density and size are similar across sites and reserve boundaries, and density is correlated with boulder cover and substrate relief. Most lobsters are gregarious, with 42% found in aggregations ≥ 3 lobsters. Proportional survival for solitary subadults is highest when tethered to shelters closely scaled to body size, indicating that shelter-scaling may be an important antipredator strategy. Additionally, subadults may experience enhanced relative survival by associating with larger conspecifics. These data will provide more information about this important species, and suggest if P. interruptus benefits from MPA establishment.
Hentschel, B.T.*, Anderson, T.W., Hayman, N.T., Renick, V.C., Allyn, J.M., Hens, J.K.
HYDRODYNAMIC MEDIATION OF KILLIFISH PREDATION ON INFAUNAL POLYCHAETES
San Diego State University
To explore predatory-prey interactions between California killifish (Fundulus parvipinnis) and spionid polychaetes (Polydora cornuta and Streblospio benedicti) in saltmarsh creeks, we conducted a laboratory flume experiment to quantify whether killifish foraging activity varies with flow speed. The flume included a 300-cm2 area of defaunated sediment within which we centrally positioned 24 P. cornuta, 24 S. benedicti, or no worms. We videotaped groups of 3 killifish for 50 min at one of 6 flow speeds (3-18 cm/s) and recorded their bite rate anywhere in sediment vs. bites directed at the central patch (98.4 cm2). The number of bites anywhere increased as flow increased from 3 to 6 cm/s, with a linear decline as flow increased further. The percentage of bites directed at the central patch varied significantly with flow and worm presence. With defaunated sediment only, ~33% of bites were directed at the central patch at all flows, consistent with a null model of non-selective foraging. When either worm species inhabited the central patch, ~65% of bites were directed at the central patch at 3 and 6 cm/s, with patch selection declining as flow increased. Despite differences in morphology and behavior, the two prey species elicited similar foraging activity by killifish.
Hessing-Lewis, M.* McKenzie, C., Keeling, B., Salomon, A.
PACIFIC HERRING SPAWNS PROVIDE TEMPORAL SUBSIDIES TO ROCKFISH DIETS
Hakai Network for Coastal People, Ecosystems and Management, Simon Fraser University
Pacific herring (Clupea pallasi), low trophic level fish at the base of many pelagic food webs, are integral to coastal social-ecological systems in North America. This migratory species provides a temporal subsidy to coastal systems by moving from offshore to nearshore waters for annual spawning events. Spawning migrations support subsistence and commercial fisheries, and provide an ecological pulse in prey availability. On the Central Coast of British Columbia, we quantified changes in rockfish (Sebastes maligerand caurinus) diet composition surrounding spawn events to understand the temporal importance of this subsidy. We found that the percentage of fish in rockfish diets switched from 30% fish tissue pre spawn to 34% herring roe post spawn, and that this shift peaked at 2-3 weeks post spawn events. This dietary change is most pronounced in females, where herring 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. Stable isotope concentrations of fish tissues (muscle, heart, liver, gonads) also showed evidence of herring nutrient assimilation. Determining these ecosystem-level associations is key to understanding both the social and ecological consequences of herring spawn declines.
† Higgins, B.A.*, Mehta, R.S.
OVERLOOKING THE APEX: BEGINNING TO UNDERSTAND THE ECOLOGICAL INFLUENCE OF THE CALIFORNIA MORAY EEL, GYMNOTHORAX MORDAX.
University of California Santa Cruz
The kelp forest ecosystem is one of the most well-studied and diverse marine communities. While overfishing and extirpation have called substantial attention to many of the apex consumers within the kelp forest, there remains a paucity of information on predators that have the potential to play a dominant role in these communities. Because of their cryptic and presumably nocturnal lifestyle, little is known of the California moray (Gymnothorax mordax). Basic ecological information with respect to their densities, habitat, growth, and diet is unknown. While the absence of a commercial fishery has left G. mordax virtually unstudied in temperate waters, we know from tropical ecosystems that the presence of morays can affect recruitment patterns as well as fish assemblages on coral reefs. Functional morphology studies reveal that morays have evolved alternative prey capture and transport strategies to consume large prey whole. Here, we seek ecological information regarding population structure, habitat, diet, and prey availability of G. mordax around Two Harbors, Santa Catalina Island, CA. We used passive integrated transponder (PIT) tags to track the growth of morays over two field seasons. Our data reveal that G. mordax are abundant near shore predators that prey on large individuals of fish and invertebrates.
† Hirschfeld, M.1,3*, Hearn, A.R.2, Denkinger, J.1
MOVEMENT BEHAVIOR OF JUVENILE BLACKTIP SHARKS (CARCHARHINUS LIMBATUS) IN THEIR NURSERY AREAS
1 – Galapagos Science Center, Universidad San Francisco de Quito, 2 – Turtle Island Restoration Network, 3 – Galapagos National Park Service
Biotelemetry research on several shark species, including blacktip sharks Carcharhinus limbatus has manifested the use of nursery areas during early life stages. New to this study is the description of a set of small-scale swimming behaviors and their association to different habitat types. By actively tracking juvenile and neonate blacktip sharks in nurseries and their adjacent areas on San Cristobal Island, Galapagos, we also investigated site fidelity, activity space and habitat preference on a local scale. The sharks made regular exploratory movements outside the protected nurseries, which differed much from swimming behaviors inside protected bays, based on swimming speed and directionality. Furthermore, juvenile blacktips showed a clear preference for habitats of distinct water depth and substrate type. Besides their exploratory behavior all individuals displayed high site fidelity and used similar-sized core areas at approximate geographic locations. Finally, our results are aimed at providing local authorities with a spatial guide to include nurseries as protected areas in the zoning scheme of the Galapagos Marine Reserve.
† Hodgson, E.E.1*, Essington, T.E.1, Kaplan, I.A.2
An ecological risk analysis of ocean acidification in the California Current
1 – School of Aquatic and Fishery Sciences, University of Washington, 2 – Northwest Fisheries Science Center, NOAA
The oceans are absorbing approximately 30% of the carbon emitted into the atmosphere, causing temperature changes and ocean acidification. However, the realized impact that ocean acidification will have on marine ecosystems remains largely unknown. Here, we adopt a risk-based framework for screening species that are most likely to be affected by changes in pH based on exposure, sensitivity, and life stage analysis. The risk metric adapts the existing approach of determining sensitivity and exposure by adding a third axis of life stage elasticity. This approach allows for an investigation of the risk faced by key species in the California Current accounting for the importance of each life stage for species’ success. The California Current is an ideal study system as low levels of carbonate saturation already exist within the near-shore environment due to upwelling, and species currently experiencing low pH will experience even lower levels earlier than those in other regions of the ocean. Species were selected based on ecological and/or economic importance. Result of this analysis, applied to Dungeness crab, pink shrimp, pacific hake, and euphausiids reveal large differences in risk based on life histories and physiological tolerance, and also reveal information gaps needed to precisely forecast ecological changes from acidification.
† Hofmeister, J. K.*, Caldwell, R.L.
UTILIZING BINOMIAL N-MIXTURE MODELS TO REVEAL THE BIOTIC VARAIABLES INFLUENCING OCTOPUS ABUNDANCE AND SMALL-SCALE DISTRUBUTION
University of California Berkeley
Octopuses play a crucial role in ecosystems worldwide, yet there lacks fundamental knowledge of the biotic interactions influencing their spatial ecology and movement behavior. This study sought to illuminate the key biotic variables influencing octopus spatial density in a rocky reef ecosystem. As generalist predators, octopuses are rarely limited by prey availability. Additionally, octopuses possess many adaptations to prevent detection and capture by their own predators. Thus, I predicted that the density of octopus predators would best explain octopus abundance and small-scale distribution. All data were collected on Catalina Island, CA. I surveyed 24 permanent transects repeatedly from June-August 2013 for octopuses, their predators, their prey, algae cover, and rugosity. N-mixture models are hierarchical models used when the detection probability of the target species is less than one. Octopuses are ideal candidates for N-mixture models given their unparalleled camouflaging ability and complex community interactions. When survey date is incorporated as a covariate influencing detectability, predatory fish abundance and rugosity best explain the observed patterns. This is the first study utilizing N-mixture models to elucidate the key ecological variables influencing octopuses. These methods can be widely applied to other octopus species and marine systems to better understand their complex environmental interactions.
† Holdridge, E.M.*
Trophic ecology of Ariid catfishes in the Gulf of Mexico
California State University, Northridge
Two species of ariid catfish, Ariopsis felis and Bagre marinus, were sampled at various sites along the northwest coast of Florida. Stomach contents of each species were analyzed in order to understand the trophic ecology of these two common fishes in the Gulf of Mexico. I qualitatively test the hypothesis that sea catfishes are more generalized predators than currently believed by comparing their observed diet with that from literature. I also analyze similarities in the diets of these two species using two common niche overlap indices in order to understand how their resource use differs, allowing them to coexist. Data from my study shows that the diets of B. marinus and A. felis are diverse but have significant overlap.
† Hong, B.*, Shurin J.B.
THE EFFECT OF TEMPERATURE MEAN AND VARIABILITY ON TIDEPOOL COPEPOD POPULATIONS ACROSS LATITUDES
University of California, San Diego
The tidepool copepod Tigriopus californicus shows a general pattern of increasing thermal stress tolerance with decreasing latitude. The effect of temperature on life history traits and population dynamics across a wider gradient, however, is unknown. We examined the temperature response between 15°C and 30°C of 15 T. californicus populations ranging across more than 17° of latitude in laboratory cultures. We found a significant positive relationship between latitude and somatic growth of nauplii that was strongest at intermediate temperatures. We also found a significant negative relationship between latitude and daily survival at the thermal extremes (15°C and 30°C), suggesting that northern populations grow faster but survive less than those from the south. In the field, we grew three northern and three southern populations in 250ml bottles submerged in tanks filled with water to simulate different sized tidepools. Tank water volume was used to manipulate nightly low temperatures, and shading treatments were used to manipulate daily high temperatures. The effect of temperature treatments on population growth varied among populations; however, that variation was unrelated to latitude of origin. Most populations grew faster at lower temperatures on average, though some were sensitive to the range of daily variability in addition to the mean. However, northern and southern populations did not vary systematically in their response. Our results indicate latitudinal trends in the response of growth and survival to thermal gradients. The effect of the daily range of temperature variation also differed among populations, but not consistently with latitude. Local selection and non-adaptive causes of genetic population structure (e.g., drift or founder effects) may both contribute to the patterns of phenotypic variation we observed.
Hovel, K.A.*, Reeve, L.D.
THE EFFECT OF DISTURBANCE ON BIODIVERSITY IS MEDIATED BY HABITAT COMPLEXITY IN EELGRASS
San Diego State University Coastal & Marine Institute
Disturbance strongly affects community structure, particularly when it involves habitat loss and fragmentation, processes that afflict a wide variety of ecosystems. Disturbance effects on community structure often involve thresholds, wherein measureable changes to biodiversity only occur beyond a tipping point of disturbance extent or frequency. In seagrass habitat, natural and anthropogenic disturbances at multiple scales result in a continuum of patchiness across the landscape, but structural complexity (e.g. shoot density) also varies among patches. We used artificial eelgrass (Zostera marina) to test whether structural complexity modifies effects of habitat loss on epifaunal community structure in San Diego Bay, CA. We allowed artificial eelgrass patches to be colonized by epifauna and then fragmented each patch to create a continuum of habitat loss (0 – 90%) for each of three complexity treatments. Epifaunal species richness decreased rapidly in low shoot density eelgrass, but only decreased after a threshold of loss was reached, or did not decrease at all, in medium and high shoot density eelgrass, respectively. Interactive effects of habitat loss and complexity were variable for other measures of community structure (e.g., epifaunal density, evenness). However, multivariate analyses revealed that the major driver of community composition was structural complexity, rather than habitat loss.
† Howard, A.C.*
EFFECTS OF TEMPERATURE ON SEXUAL COMPETITION IN KELPS
Moss Landing Marine Laboratories
Kelp populations inhabit some of the most dynamic environments on the planet and often exist close to the limits of their temperature tolerances. Temperature cues reproductive processes in many kelps and fluctuating temperatures can affect kelp recruitment and population persistence. Some kelps compete sexually through their microscopic life history stages by releasing a pheromone that triggers the premature release of spermatozoids of neighboring species, leading to recruitment failure. It is unknown, however, whether changing temperature modifies competitive hierarchies among kelp species. To address this issue, I investigated how temperature affects sexual competition between microscopic stages of three co-existing and possibly competitive kelps in central California. Laboratory studies were conducted to test the effects of temperature on germination, gametogenesis, and fertilization. At 8°C and 12°C,Macrocystis pyrifera outcompeted Nereocystis luetkeana, but was outcompeted by Pterygophora californica. At 16°C, Nereocystis did not survive and Pterygophora sporophyte recruitment decreased relative to that of Macrocystis. These results suggest that increasing ocean temperatures due to climate change will favor Macrocystis over Nereocystis and Pterygophora, increasing Macrocystis’ dominance along the central California coast.
† Huotari, K.E.*, Bros-Seemann, S.M.
THE ADVANTAGE OF INCORPORATING FUNCTIONAL GUILDS INTO MODELS OF BENTHIC DIVERSITY
San José State University
Clear trends in how physical characteristics of benthic habitat affect species diversity have not emerged. Species diversity is commonly used in research, but is not the most biologically- descriptive measurement. Biologically meaningful measures, such as functional diversity (e.g. feeding, motility, and domicile guilds) may yield a better understanding of underlying processes than species diversity alone. We examined changes in functional diversity with respect to particle size and particle heterogeneity from data collected in a 2003 Moss Landing Marine Lab benthic survey in Elkhorn Slough, CA. Each species was assigned to feeding, motility, and domicile guilds for analyses. The results indicated that, while species and motility guild diversity does not change with respect to particle size or heterogeneity, there were differences in feeding and domicile guild diversity. Both feeding and domicile guild richness increases with heterogeneity and evenness for both guilds decreases with particle size. Unlike the measure of species diversity, feeding and domicile guild diversity are more directly related to the biology of the organisms, and, by using these measures, it was possible to identify trends previously unknown.
† Hurley, K.K.1*, Copus, J.M.1, Skillings, D.J.1,2, Timmers, M.A.1, Toonen, R.J.1
DO MESOPHOTIC CORAL REEFS PROVIDE DEPTH REFUGE FROM ANTHROPOGENIC CLIMATE CHANGE?
1 – Hawaiʻi Institute of Marine Biology, University of Hawaiʻi at Mānoa, 2 – Brooklyn College
Mesophotic coral reef ecosystems (MCEs) are hypothesized to play a critical role in maintaining reef biodiversity. According to the deep reef refugia hypothesis (DRRH), shallow-water species may move deeper during climatic disturbances; these deeper reefs then serve as a source from which shallow reefs may be repopulated as pre-disturbance conditions return. Shallow coral reefs of Hawaii are extensively studied, and although scleractinian corals have been recorded to 165 m, little is known about other reef inhabitants. Brachyuran crabs are fundamental to reefs and fill many ecological and trophic niches, making them ideal candidates for evaluating species richness on a depth gradient (30, 60, and 90 m) relative to among shallow sites. Autonomous Reef Monitoring Structures (ARMS) were deployed for two years for the collection of samples. Species richness was assessed using morphological and molecular systematics. Over 15 genera (representing over 8 families) were found across the depth gradient. As communities are more consistent across geographically disparate shallow sites than among depths at the same site, the DRRH is not supported. In other words, if sea levels rise, crabs from deeper reefs cannot be expected to repopulate future shallow reefs, and crabs from the shallows may not be maintained.
Jacobs, D.K.*, Ellingson, R., Dolby, G., Swift, C.C.
ESTUARINE HABITAT AND SPECIATION PROCESS IN BAY GOBIES: CRYPTIC TAXA, ANTHROPOGENIC IMPACTS AND RESTORATION CONFLICTS
North Pacific “bay gobies” are phylogenetically subdivided East/West across the Pacific-ecological distinction relating to infaunality evolved in parallel on both coasts. In the17 primarily estuarine eastern Pacific species, diversity is high on the California Coast and higher still in the Gulf of California. Bay Goby species prefer discrete types of estuarine habitat. Our work demonstrates that: 1) Gobies endemic to the Gulf of California evolved prior to the tectonic formation of the Gulf. 2) The federally endangered tidewater goby, Eucyclogobius newberryi, which prefers seasonally closing habitat, shows dramatic subdivision at very small spatial scales. 3) Tidal channel and flat specialists such as Quietula y-cauda andGillichthys mirabilis show intermediate differentiation as a product of isolation of estuarine habitat at glacial low-stand. 4) Cryptic diversity at the species level is evident within the Gulf of California where we recently resurrected Gillichthys detrusus a Colorado Delta endemic, and in southern California withinEucyclogobius. 5) Overall habitat specificity influences dispersal, genetic structure, speciation and endangerment. In our view, greater concern should be exhibited regarding how management action, including habitat restoration, impacts local unique genetic units many of which remain to be assessed.
† Johnson, A.M.*, Karels, T.J.
EFFECTS OF HABITAT FRAGMENTATION ON RODENT SPECIES RICHNESS IN SOUTHERN CALIFORNIA
California State University Northridge
Habitat Fragmentation plays a major role in species extinction and the loss of biodiversity around the globe through three main processes: (1) overall loss of habitat, (2) continued reduction in the size of remaining habitat fragments, and (3) continued isolation of remaining habitat fragments. Previous research on habitat fragmentation determined that species richness in habitat fragments is affected by a number of characteristics. These include fragment size, isolation, edge effects, vegetation coverage, habitat heterogeneity, and matrix content. While most studies focused on only one or a few of these characteristics, multiple characteristics work together to affect species richness, showing that the effects of habitat fragmentation are complex. My study will break apart the complex effects of habitat fragmentation by determining the direct, indirect, and cumulative effect of multiple habitat fragmentation characteristics on rodent species richness. In 2013, I determined rodent species richness in 25 habitat fragments in Thousand Oaks, California. In addition, I measured the following characteristics for each fragment: fragment age, area, isolation, shrub coverage, habitat heterogeneity, perimeter/area ratio, and percent urban perimeter. Path Analysis will be used to test the hypothesized model describing the direct, indirect, and cumulative effect of the measured characteristic on rodent species richness.
† Jones, E1,2*, Long, J.D.1
The relative strength of an induced seaweed defense varies with herbivore species
1 – San Diego State University, 2 – Bodega Marine Laboratory, UC Davis
Herbivore species may interact indirectly via induced trait changes in food resources. For instance, herbivore grazing can alter seaweed palatability, in turn, increasing or decreasing susceptibility to other herbivores. Although herbivore identity is often important for eliciting these trait changes, we know little about how the strength of induced responses varies with herbivore species. To investigate this question, we first exposed the seaweed Silvetia compressa to grazing by isopods (Idotea wosnesenskii), snails (Chlorostoma funebralis), or the two herbivores together. After two-weeks, we compared the relative palatability of our treatments by offering each herbivore species a choice between conspecific grazed tissues and either 1) non-grazed tissues, 2) heterospecific grazed tissues, or 3) tissues grazed by both herbivores. We found that both species significantly preferred non-grazed tissues over conspecific grazed tissues, confirming induced changes in palatability. When we directly compared Idotea and Chlorostomainduction, snail grazed seaweeds were significantly less palatable than isopod grazed ones. However, conspecific grazed tissues did not differ in palatability from combination-grazed tissues. Thus, while both herbivores decrease Silvetia palatability, the relative strength of this response varies with grazer identity. These interactions may have important implications in communities where seaweeds are exposed to a variety of interacting herbivores.
† Jurgens, L.J.*, Gaylord, B.
WET BLANKET OR HOT BLACKTOP? A CLOSE LOOK AT THERMAL MICROHABITATS IN MUSSEL BEDS REVEALS RADICAL DIFFERENCES ON CENTIMETER SCALES
Bodega Marine Laboratory, University of California Davis
Habitat-forming species such as mussel beds harbor an enormous fraction of the biodiversity found on rocky shores. Like terrestrial forests in miniature, rocky intertidal foundation species can alter environmental conditions, including temperature and humidity. These physiologically important factors can vary profoundly across space even within a habitat, and substantially different conditions may arise at the top surface or canopy compared to the interior. Using a widespread foundation species – the California mussel, Mytilus californianus – we explored patterns in temperature maxima and relative humidity at the upper surface and interior of mussel beds during low tide emersion. Peak temperatures at the mussel bed surface frequently exceeded 35° C, often surpassing adjacent bedrock temperatures. In contrast, the bed interior rarely reached 20° C and maintained comparatively high humidity. These microhabitat differences strongly affected size-specific mortality risk and habitat use in sub-adult mussels. Such radically different thermal microhabitats over centimeter scales have implications for population dynamics and climate change risk for mussels, as well as for the hundreds of invertebrate species that utilize the beds produced by them. Our findings underscore the potential for foundation species to have complex physical effects on organism-scale climate.
† Kapsenberg, L.*, Hofmann, G.H.
FROM KELP TO ICE: TEMPORAL AND SPATIAL VARIABILITY IN OCEAN PH
University of California Santa Barbara
In the face of rapid ocean change, assessing the evolutionary potential of important marine species presents a great challenge. Understanding spatial and temporal pH variability in the current ocean environment will ground biological laboratory studies and improve experimental design of field-based ocean acidification studies. In this presentation we will compare and contrast pH time series (recorded using autonomous SeaFET pH sensors) from different marine ecosystems, in this case, near-shore Antarctica and two sites in the Channel Islands National Park. The data show that biological processes dominate near-shore pH variability on a diurnal timescale as measured by dissolved oxygen concentration and pH interactions. Over one year, pH predominately varied between 7.8 and 8.2 in the Channel Islands. In contrast, surface waters in Antarctica undergo a strong alkalinization event during the austral summer. This alkalinization is linked with ice algae presence and results in a seasonal pH increase from 8.0 to 8.3. In addition to generating baseline data sets of ocean pH, these time series data are critical in order to assess the capacity of marine organisms to adapt to ocean change.
Kelly, M.W.*, Padilla-Gamilo, J.L., Hofmann, G.H.
NEXT-GEN SEQUENCING TO IDENTIFY THE GENETIC BASIS OF PH TOLERANCE IN THE CALIFORNIA MUSSEL
UC Santa Barbara
Exposure to projected future ocean acidification leads to reduction in size for calcifying larvae of many different taxa. However, recent work has also shown that the response to pH is both variable and heritable in several species. In this experiment, we sought to identify genes involved in pH tolerance in the California mussel, Mytilus californianus, using transcriptome sequencing. We created three crosses and reared offspring from each cross under ambient (~380µatm, pH=8.05) and high (1250µatm, pH=7.6)pCO2 conditions. At 63 hours post fertilization, we passed larvae from each culture through a 64µm mesh filter separating each family x pCO2treatment into a fractions of larvae with large vs. small body sizes. We prepared libraries from the bulk RNA extracted from each of the 12 family x treatment x body size combinations and sequenced all 12 libraries on a single lane of Illumina (100 bp, PE). From ~80 million pairs of cleaned, filtered reads, we assembled a de novo transcriptome for M. californianus. We then mapped reads from each library back to this assembly to identify effects of high pCO2 on gene expression, and genetic differences between larvae tolerant of high pCO2 those that remained normal size) and larvae that were sensitive to high pCO2 (those that were smaller than under ambient conditions). Our results provide important insights into the mechanistic basis of resilience to ocean change in a key foundation species of the eastern Pacific intertidal zone.
Kim, N.1*, Kim, J.-H.2, Edwards, M.3
PRELIMINARY STUDY OF INORGANIC CARBON UTILIZATION BY UNDERSTORY MACROALGAE IN A GIANT KELP FOREST
1 – Torrey Pines High School, 2 – Chonnam National University, 3 – San Diego State University
As concerns regarding global climate change increase, research on species-specific carbon acquisition strategies is more important to predict the effects on ocean acidification on kelp forest ecosystems. In this study, we investigated the characteristics of photosynthesis and carbon utilization strategies of several understory macroalgal species in a kelp forest. Specifically, nine species of fleshy macroalgae with diverse photosynthetic capacities were placed under low light conditions (34.88 ± 12.08 µmol photons m-2s-1) and their reliance on CO2 and HCO3– as a carbon source inphotosynthesis evaluated. Under these conditions, their apparent half-saturation constants for HCO3– (K(1/2) HCO3–) ranged from 0.17 to 0.72 (mean value = 0.41 ±0.21 μM HCO3–), indicating that most of these species were already nearly carbon saturated under current ocean carbon concentrations. In addition, according to pH compensation points (ranged from 8.34-9.12), most species preferred utilizing CO2 as a source for photosynthesis. Consequently, we postulate that these macroalgae will have a physiological advantage under elevated CO2 conditions with respect to their carbon utilization strategies.
Kinlan, B.P.1,2*, Menza, C.1, Bauer, L.B.1,2, Caldow, C.1
PREDICTIVE SPATIAL MODELS FOR MULTI-SPECIES BYCATCH RISK EVALUATION AND SPATIAL PLANNING IN THE U.S. PACIFIC GROUNDFISH FISHERY
1 – NOAA NOS National Centers for Coastal Ocean Science (NCCOS), 2 – CSS-Dynamac
Studies of strategies to reduce bycatch and improve spatial management in multi-species fisheries highlight the importance of spatial information on the distribution of fish. Yet, for large marine ecosystems, spatial information on fish distribution can be prohibitively costly to collect by direct sampling alone. Fish occurrence and abundance vary tremendously on scales of meters to kilometers, yet fisheries operate over 10’s to 1000’s of km. Statistical models that integrate field survey data with other available information (ecology, habitat) can aid spatial management by making predictions about the relative occurrence probability and abundance of species in between survey locations. We developed spatially explicit predictive models for 15 species in the U.S. Pacific Groundfish species complex, including 7 overfished species (OFS) and 8 non-overfished commercially targeted species (TS) with overlapping spatial distributions, and used these models to evaluate strategies to reduce bycatch of OFS while maximizing catch of TS. Models integrated species-specific ecological information and habitat data with observations from the 2003-2010 annual West Coast Groundfish Bottom Trawl Surveys conducted by the NOAA Fishery Resource Analysis and Monitoring (FRAM) Division to make spatial predictions that allow evaluation of alternative multi-species spatial management and bycatch avoidance programs at a California Current Ecosystem-wide scale.
† Kollars, N.M.1*, Byers, J.E.2, Sotka, E.E.1
EVIDENCE FOR A CONTEXT-DEPENDENT MUTUALISM BETWEEN A NON- NATIVE SEAWEED AND A NATIVE DECORATOR POLYCHAETE
1 – College of Charleston, 2 – University of Georgia
Mutualisms between non-native and native species can be fundamental drivers of invasions but are less frequently described in marine systems. The association between the non-native seaweed Gracilaria vermiculophylla and the native polychaete Diopatra cuprea may represent one of the first examples of a marine mutualism between a non-native and native species. In the estuaries of South Carolina and Georgia, the decoration behavior of Diopatra facilitates the growth of G. vermiculophylla by anchoring the seaweed in a favorable photic zone. G. vermiculophylla may reciprocally benefit Diopatra by providing the polychaete with a valuable food source. In the laboratory, Diopatra growth was greater when provided a diet of G. vermiculophylla relative to mud-only controls. However, this fitness benefit was not consistent across multiple field experiments as we found high spatial (Charleston, SC versus Savannah, GA) and temporal (early versus late summer) variation in the effects of Gracilaria on the growth and survivorship of Diopatra. This suggested G. vermiculophylla is not the only ecological force driving the fitness of Diopatra and that the nature of the interaction is context-dependent. Future research should examine the effects of the larger biological community and abiotic stressors on determining interaction strength in the Diopatra-G. vermiculophylla association.
Konar, B.*, Iken, K.
Monitoring of rocky coastal communities as part of the Gulf Watch Alaska Program
University of Alaska Fairbanks
Gulf Watch Alaska is a monitoring effort that is collecting physical and biological data in Kachemak Bay, Prince William Sound, the Kenai Fjords, and the Gulf of Alaska shelf. Among the biological data collected in coastal areas, rocky intertidal beaches are being surveyed for algal and invertebrate composition and density along with size frequencies for mussels and limpets. In Kachemak Bay, sampling is being completed at four distinct depth strata (high, mid, low and 1 m) in May of each year. Here, five rocky intertidal sites that are exposed to various degrees of glacial discharge are being monitored. Glacial discharge can have a large influence on nearshore communities and as such is an important environmental driver in northern coastal communities. Our monitoring efforts show distinct community differences among sites, which are consistent across years. Additionally, we see differences in mussel and limpet size frequencies and mussel recruitment among sites. Supplementary rocky subtidal community and recruitment data along this glacial influenced gradient show similar patterns in community composition and recruitment patterns. Climate warming increases glacial melt along high latitude coastlines and monitoring of these coasts is essential for understanding how climate change will impact these systems.
† Kram, S.L.1*, Price, N.N.1, Kelly, E.L.A.1, Gleason, M.1, Hamilton, S.L.2, Smith, J.E.1
Response of calcified and non-calcified southern California seaweeds to increased CO2 and temperature
1 – Scripps Institution of Oceanography, 2 – Moss Landing Marine Laboratories
Anthropogenic carbon dioxide levels have increased rapidly in the past century, leading to global change phenomena such as warming and ocean acidification (OA). Declining oceanic pH and carbonate saturation state associated with OA is anticipated to negatively affect growth of calcified algae, but it is unclear how OA will impact non-calcifying algae. Likewise the combined effects of OA and warming on seaweeds are largely unknown. We conducted CO2 enrichment and warming experiments with 2 southern California red calcifying and non-calcifying seaweeds and measured changes in growth, chlorophyll fluorescence, carbonic anhydrase activity, pigment concentration and photosynthetic oxygen production over one month. We designed replicated novel seawater flow-through experimental aquaria to allow specimens to experience natural pH and temperature fluctuations without nutrient limitation. Increased temperature had significant negative consequences for the growth of non-calcified algae but increased temperature and CO2 offset some of that negative effect. However, calcified algae were only negatively affected by OA. Elevated CO2 and/or temperature did not significantly affect the other response variables. These results suggest calcified algae may be less competitive under acidic oceanic conditions, but are less threatened by warming. Non-calcified algae may be threatened by warming, but the addition of OA may lessen that negative effect.
† Krueger-Hadfield1,2*, Roze, D.1, Destombe, C.1, Valero, M.1
O FATHER, WHERE ARE THOU? PATERNITY ANALYSES IN A NATURAL POPULATION OF THE RED SEAWEED Chondrus crispus
1 – Equipe BEDIM, Station Biologique de Roscoff, France, 2 – Grice Marine Laboratory College of Charleston
Chondrus crispus follows an isomorphic haploid–diploid life history in which male gametophytes release non-motile spermatia and fertilization is followed by zygotic amplification. The objective of this study was to understand the impacts of haploid-diploidy, male gamete dispersal and the intertidal shorescape on the genetic structure of C. crispus. Individual fronds were sampled every 25 cm in two 5mx5m grids located high and low on the shore. Fronds (N=472) and cystocarps (N=565, excised from 29 female gametophytes) were genotyped using polymorphic microsatellite loci. The maternal allele at each locus can be determined from the haploid female thallus. The remaining allele is the paternal contribution. Large levels of inbreeding detected using indirect methods were supported by the paternity analyses. Larger kinship coefficients were detected between males siring cystocarps on the same female than between males in the entire population. However, only 1 of 424 sires was sampled in the populations suggesting fertilization distances of less than 25 cm. More detailed sampling of genets is necessary to resolve the high levels of inbreeding and genetic structure within the intertidal shorescape.
Krumhansl, K.A.1*, Lauzon-Guay, J.S.2, Scheibling, R.E.1
MODELING EFFECTS OF CLIMATE CHANGE AND PHASE SHIFTS ON DETRITAL PRODUCTION OF A KELP BED
1 – Biology Department, Dalhousie University, 2 – Fisheries and Oceans Canada, Institut Maurice-Lamontagne
The exchange of energy and nutrients between ecosystems plays a central role in ecological dynamics over a range of spatial and temporal scales, but little attention has been paid to the potential for anthropogenic impacts on natural systems to alter the dynamics of material exchange between ecosystems. We generated a model of detrital production from a kelp bed in Nova Scotia, and used this model to predict that historical (measured in the study region from 1976-2009) increases in temperature have led to an increase in detrital production and a decline in kelp biomass. Projected increases in temperature and wave height due to future climate change caused short-term increases in detrital production, but this rate declined in the long-term as kelp biomass was reduced. We also used the model to demonstrate that phase shifts from kelp beds to barrens caused by grazing sea urchins reduce kelp detrital production by several orders of magnitude, an effect that would be exacerbated by projected increases in temperature and wave action. These results indicate that climate-mediated changes in ecological dynamics operating on local scales may alter the magnitude of resource subsidies to adjacent ecosystems, affecting ecological dynamics over broader scales than previously considered.
Kushner, D.1*, Shears, N.2
REGIONAL-SCALE RECRUITMENT PATTERS DETERMINE RESERVE EFFICACY ACROSS AN ISLAND MARINE RESERVE NETWORK
1 – Channel Islands National Park, 2 – Leigh Marine Laboratory, University of Auckland
Our understanding of the effectiveness of marine protected areas in protecting and promoting exploited species is largely derived from spatial comparisons between reserve and fished sites or from a limited number of reserves where before and after protection data are available. The establishment of networks of marine reserves worldwide provides increased opportunity to examine how exploited species respond to protection across regions and determine important factors driving variation in response of exploited species to protection. We utilize a unique marine monitoring data set that spans 30 years, 6 reserves, and two biogeographic regions, to investigate the response of a heavily harvested sea cucumber (Parastichopus parvimensis) to protection. Clear regional variation was found in sea cucumber abundance and harvest levels across the Channel Islands, with both density and fisheries landings increasing with warming water temperatures from west to east. Concomitant with this was higher rates of recovery in reserves in the warmer region and a greater overall magnitude of reserve effects. These patterns correspond to higher recruitment levels in the warmer region.. These results provide a unique example of how monitoring data from a network of marine reserves can be used to assess and interpret variation in the performance of MPAs and develop better predictions as to how exploited species will respond to protection.
† Kwan, C.K.1,2*, Long, J.D.1
COPPER WEAKENS TRAIT-MEDIATED INDIRECT INTERACTIONS IN A TRI-TROPHIC SYSTEM OF PREDATORY CRABS, INVASIVE WHELKS, AND BARNACLES
1 – Coastal and Marine Institute Laboratory, San Diego State University, 2 – Bodega Marine Laboratory, University of California Davis
Recent studies have emphasized that predator-induced modifications of prey traits strongly influence community structure. Trait-mediated indirect interactions can occur when chemical cues from a predator alter prey behavior with effects on the prey’s resource. However, we know very little about the context-dependency of indirect interactions, especially under polluted scenarios. Pollutants might influence sensitivity to predator cues and shift the relative importance of trait- and density-mediated indirect interactions and, thus, the functioning of marine communities. We examined the effects of copper on an estuarine tri-trophic system consisting of the crab Cancer productus, which feeds on the invasive whelkUrosalpinx cinerea, a predator on Balanus barnacles. These species co-occur in San Francisco Bay, a heavily polluted estuary. In laboratory experiments, we exposed these interacting organisms to a range of copper concentrations, including levels typical of heavily polluted marinas in the United States. In the absence of copper, crab cues induced predator avoidance behaviors in whelks and reduced their consumption on barnacles. Increasing copper concentrations weakened the effect of crab cues on whelk consumption of barnacles. Our study represents one of the first in marine systems to show that contaminants at ecologically realistic concentrations can alter indirect interactions between predators and basal resources.
† Labou, S.G.*, Henkel, S.K.
PHYSICAL FACTORS AFFECTING THE DISTRIBUTION OF INFAUNAL BIVAVLE ASSEMBLAGES ALONG THE CONTINENTAL SHELF OF THE PACIFIC NORTHWEST
Hatfield Marine Science Center, Oregon State University
The spatial distribution patterns of benthic infauna result from interactions with a host of environmental variables including sediment characteristics, depth, temperature, and dissolved oxygen. The study discussed here focuses on the association of infaunal bivalve assemblages with potentially influential environmental variables along the continental shelf of the Pacific Northwest. Data for this research comes from a survey funded by the Bureau of Ocean Energy Management (BOEM), conducted in 2010. Across the six sites sampled, eight distinct bivalve assemblages were identified using non-metric multidimensional scaling and SIMPER analysis from the ecological software PRIMER 6. Environmental characteristics associated with each assemblage were determined. Percent silt-clay was the most useful environmental variable for distinguishing bivalve assemblages by habitat, with major differences between sandy and silty areas. Within predominantly sandy habitats, changes from one bivalve assemblage to another were associated with small differences in the remaining percentage of silt-clay in the sediment, whereas within predominantly silty habitats, changes in assemblage were associated with changes in depth, rather than exact percent silt-clay. These results can be used to inform the selection of appropriate control sites for assessing wave energy device impacts on benthic infauna.
CONTAMINANT COCKTAILS: EFFECTS OF MULTIPLE STRESSORS IN ESTUARIES ON MARINE INVERTEBRATES
1 – Evolution and Ecology Research Centre, University of New South Wales, 2 – Sydney Insitute of Marine Science
Contaminant cocktails are increasingly common in our estuaries and understanding stressor interactions is important to predict changes in ecosystem structure and function. Nutrient enrichment is a prominent stressor, often found with metals, from sewage and industrial activity. Sessile marine invertebrate larvae often settle in response to environmental cues, and cues can be affected by contaminants. We present two studies investigating effects of elevated nutrients with metals on sessile invertebrate recruitment and assemblage structure. First, we elevated nutrient and copper levels and tested their impact on invertebrate abundance through time. Nutrients increased recruitment settlement, while copper had the opposite effect. Barnacles and ascidians, in particular, responded to elevated nutrients. Second, we manipulated biofilm presence and growth conditions under elevated nutrients and quantified the 5d bacterial community before a 7d invertebrate recruitment period. DAPI fixed-staining revealed that elevated nutrients reduced bacterial abundance. Pre-filming of settlement plates affected community composition by increasing recruitment of organisms, regardless of elevated nutrients. Again, elevated nutrients increased barnacle and solitary ascidian recruitment, but reduced recruitment of other organisms that preferred the natural biofilm. These consistent responses to nutrient inputs, in conjunction with metal pollution, highlight the importance of examining both micro- and macro-level responses to contaminants.
† Leary, P.L.1*, Walter R.K.2, Denny M.W.1, Micheli F.1, Monismith S.G.2, Woodson, C.B.3
HYPOXIA IN THE KELP FOREST, HYDRODYNAMICS AND SPATIAL VARIABILITY
1 – Stanford University, Hopkins Marine Station, 2 – Stanford University, 3 – University of Georgia
In coastal upwelling systems, severe hypoxic pulses on the inner shelf occur often, though their intrusion into the shallow subtidal has been documented only recently, and their hydrodynamics and resulting effects on rocky reef communities are largely unknown. The primary driver of coastal hypoxic events in Monterey Bay is horizontal transport by internal waves. Most research on internal waves has been conducted over smooth bottoms, and modification of waves by complex topographies such as kelp forests and rocky reefs has been largely unstudied. There are many potential mechanisms in the interaction between internal waves and reefs that could create complex three-dimensional variability in the dissolved oxygen (DO) field within a single kelp bed. Beginning in summer 2012, these mechanisms and their resulting DO variance have been investigated using moored instruments, water column profiling, and mobile diver-operated instruments. DO at the sea floor may vary spatially by 40% within an ~1800m2 kelp bed, or be almost uniform, depending on phasing of the internal wave event. These spatial DO variances exist during times of both normal (~8 mg/l) and hypoxic (<4.6mg/l) average dissolved oxygen. Spatial and temporal variance in dissolved oxygen may be an overlooked driver of variability in kelp-forest communities.
Shifting baselines of a rocky reef foodweb: Place and time matter to northern abalone conservation
Coastal Marine Ecology and Conservation Lab, School of Resource and Environmental Management, Simon Fraser University
Shifting and arbitrary baselines elicit vexing conservation challenges when society comes to value attributes of an altered ecosystem and perceives it as “normal”. Northern abalone in BC rocky reefs is one such case where sea otters, important abalone predators, were hunted to extirpation a century ago. Without otters, populations of their benthic macroinvertebrate prey increased dramatically. Poor fisheries management then led to precipitous declines in northern abalone abundance, its listing as a threatened species, and recent uplisting to endangered status. Re-introduction and range expansion of sea otters in recent decades is again shifting the macroinvertebrate and kelp community. Conservation management for abalone and sea otters becomes complex given that both are listed as species-at-risk in Canada, and that abalone abundance in the absence of sea otters currently informs recovery targets. To understand how recovery of sea otters is impacting northern abalone, we use multiple lines of evidence to improve our understanding of historical and contemporary trajectories of rocky reef ecosystem change, including observational data across gradients of sea otter occupation, historical records, and traditional knowledge. While poaching remains a threat, this historical ecosystem context challenges us to re-evaluate the status of northern abalone and targets for conservation.
† Lenz, E.A.1*, Bramanti, L.2, Edmunds, P.J.1
GORGONIANS OF THE CARIBBEAN: SUCCESS IN A CHANGING SEA
1 – California State University Northridge, 2 – Ocean Observatory of Banyuals
As coral reefs continue to be impacted by anthropogenic activities, long-term studies have become essential to determine how the structure and function of their benthic communities are changing. The degradation of scleractinians has occurred in association with changes in benthic communities favoring other taxa, most frequently macroalgae. We used data from local (<10 km) and regional (200-4000 km) scales to test the hypothesis that gorgonians have changed in abundance on Caribbean reefs over multiple decades. At the local-scale, we examined the abundance (colonies m-2) of gorgonians on the reefs of St. John, US Virgin Islands using photoquadrats (0.25 m-2) recorded every 5 y from 1992-2012. At the regional-scale, we used results from St. John with a literature survey of studies completed between 1968-2013. In St. John, mean abundance of erect gorgonians increased 42% from 1992-2012, with each of the dominant genus (Gorgonia, Eunicea, Antillogorgia, Plexaura, Plexaurella, and Pseudoplexaurella) increasing 11-221% over the same period. Regionally, the data compilation shows that gorgonians have increased in abundance with mean densities rising from 7.0 to 15.1 colonies m-2 over the last 45 years. This study highlights the potential success and importance of octocorals on contemporary coral reefs as scleractinian corals decline.
† Lindsley, A.J.*, Heppell, S.A.
THE JUVENILE ROCKFISH OF YAQUINA BAY, OREGON
Oregon State University
Oregon estuaries are important nursery habitat for young-of-the-year (YOY) Pacific rockfish and Yaquina Bay has been identified as essential fish habitat (EFH) for juvenile black rockfish (Sebastes melanops). YOY yellowtail rockfish (S. flavidus), copper rockfish (S. caurinus), quillback rockfish (S. maliger), widow rockfish (S. entomelas) and blue rockfish (S. mystinus) have also been detected in Yaquina Bay. I am attempting to determine the rockfish species present and their temporal utilization of Yaquina Bay as nursery habitat, the use of natural eelgrass (Zostera marina) habitat versus piers (artificial structure) and gather information about their movement, ontogeny and recruitment to the adult population. Sampling has been conducted during the spring tides for 17 months, methods include trapping and seining. Juvenile rockfish are tagged with visible implant elastomer. Abundance fluctuates seasonally and the species demonstrate high site fidelity.
Long, J.D.1*, Rinehart, S.A.1, Miller, L.P.2
FLIP IT AND REVERSE IT: INTERTIDAL ELEVATION SWITCHES THE IMPACT OF HERBIVORES ON SPARTINA GROWTH
1 – San Diego State University, 2 – Stanford University
Across their normal ranges, organisms experience striking differences in abiotic factors that may shape their interactions with each other. For example, intertidal herbivory in salt marshes may depend upon elevation because of associated changes in thermal, desiccation, and salinity stress. Unfortunately, the role of elevation on intertidal species interactions remains incomplete, in part, because previous studies exposed organisms to unrealistic tidal conditions. We conducted a mesocosm experiment that examined the impact of scale density (6 levels) and intertidal elevation (4 levels) on Spartina performance. We designed a tide controller that exposed organisms to realistic water levels and rates of ebb and flow. Consistent with previous studies, Spartina grew faster at lower elevations. The impact of scales depended strongly upon elevation. Scales had no effect on plant performance at the two highest elevations. Surprisingly, the direction of the effect of scales on plant growth switched between the two lowest elevations. Scales reduced Spartina growth at our intermediate-low elevation. However, moving only 15 cm lower in elevation led to a positive impact of scales on Spartina growth. These results suggest that elevation eliminated the ability of plants to display compensatory responses to herbivory.
† Lord, J.P.*, Whitlatch, R.B.
Space Race: Geographic Variability of Growth Rate and Competition in Fouling Communities
University of Connecticut Avery Point, Marine Science Department
Epibenthic fouling communities are comprised of organisms such as sea squirts, sponges, and bryozoans that grow on docks, boats and other artificial structures. These communities are useful for studying community composition because of the importance of growth rate, overgrowth competition and space limitation. Even though fouling data on invasions and community shifts show correlations with climate change, causation cannot be established without studies of thermal responses and other underlying mechanisms. This study experimentally assessed temperature-dependent growth rates of several tunicates and bryozoans in 8 regions along the US east and west coasts, from southern California to Alaska and Florida to Maine. Several encrusting species showed significant changes in growth rate in response to increased temperature. Photo surveys of floating docks were also conducted at 20 harbors in each region in order to compare communities and overgrowth competition. On the west coast of the US, competition between encrusting ascidians and bryozoans was more intense at southern than northern sites, and invasive species tended to be dominant competitors. The ultimate goal of this project is to predict the impact that invasive species will have on fouling communities after the invasives are introduced and become established in a new region.
† Lorda, J.1,2*, Bonel, N.3,4
GROWTH AND BODY WEIGHT VARIABILITY OF THE INVASIVE MUSSEL
LIMNOPERNA FORTUNEI (MYTILIDAE) ACROSS HABITAT AND SEASON
1 – University of California Santa Barbara, 2 – Tijuana River National Estuarine Research Reserve, 3 – Universidad Nacional del Sur, 4 – Consejo Nacional de Investigaciones Científicas y Técnicas
The freshwater mussel, Limnoperna fortunei, is adapted to colonize a wide range of aquatic environments, and its ability to contend with environmental stress through phenotypic plasticity has allowed this species to successfully colonize and become established in new regions. Only limited information is currently available on the widely intraspecific variability of this species in response to environmental heterogeneity. Here, we tested the hypotheses that (1) growth and body weight of mussels from a highly polluted environment differed from those from a less polluted habitat, and (2) growth parameters estimated in this study differed from those reported for other invaded ecosystems. We conducted controlled field experiments in two study sites with differing levels of pollution. To compare our results to those reported elsewhere, we considered growth data from studies performed in different locations. We found that mussels from the more polluted habitat showed lower shell growth and body weight than those from the less polluted environment. We also observed differences in the growth performances of the golden mussel between our estimates and those from other invaded habitats. Our findings provide useful information to better understand the striking intraspecific variability of this species in response to stressful conditions. Knowledge on the phenotypic plasticity of L. fortunei is essential for predicting and managing this species within new and existing populations.
Lyons, K1, Jarvis, E.T.2, Jorgensen, S.3, Weng, K.4, O’Sullivan, J.3, Winkler, C.5, Lowe, C.G.*
Assessment of GILLNET fisheries interactions with juvenile white sharks in southern California
1 – California State University Long Beach–Shark Lab, 2 – Orange Co. Sanitation District, 3 – Monterey Bay Aquarium, 4 – University of Hawaii, 5 – Southern California Marine Institute
Previous reports have documented juvenile white shark interaction with gillnet fisheries in southern California; however, there has been no quantification of the degree of this interaction via fishery-independent methods. We used geopositioning data from juvenile white sharks fitted with acoustic (n = 11) or satellite transmitters (SPOT) (n = 13) and fisheries data collected from 2006 to 2012 to determine the degree and effect of white shark interactions with the gillnet fisheries in southern California. Set gillnet effort comprised a majority of the total gillnet effort (88%) and both set gillnet and inshore drift gillnet effort were significantly and positively correlated with incidence of white shark capture (p < 0.0001) and number of SPOT detections (p < 0.0001). Although juvenile white sharks were shown to overlap with gillnet fisheries in their vertical and horizontal distributions, post-release survival of sharks retrieved alive in gillnets was high (92.9%). While shark bycatch mortality occurred over this time period (42±24%), sharks were more often found alive in gillnets when mean net soak times were low. Future management may consider lowering net soak duration to reduce incidental capture mortality and improve incidental capture survival of white sharks at their most vulnerable age class.
† Lürig, M.D.1,2*, Best, R.J.1, Stachowicz, J.J.1
Microhabitat selection by Seagrass mesograzers: effects of predation, trait variation and species interactions
1 – Bodega Marine Laboratory UC Davis, 2 – Carl von Ossietzky Universität Oldenburg
Seagrass ecosystems worldwide depend on the mutualistic relationship between habitat-forming organisms and epiphyte-consuming grazers. A diverse assemblage of grazers appears to better control epiphyte growth, but grazer diversity varies widely among beds and it is not clear what factors allow the coexistence of many grazer species. While recent studies have focused on the influence of abiotic gradients and habitat structure on this group of invertebrates, species-specific microhabitat preferences, predator-avoidance and habitat competition could affect coexistence among grazers. To address this, we compared the habitat preferences of 8 seagrass mesograzer species from Bodega Harbor, CA and tested how these preferences varied with the presence of (a) predators and (b) competitors that are either similar or dissimilar in habitat selection and traits. We found significant differences in habitat preferences among species, with some consistently choosing Ulva, eelgrass, or open habitat. The presence of predatory fishes did not change these preferences. The presence of other mesograzer species altered habitat selection to a variable extent, which may depend on the two species’ overlap in important traits such as tube-building ability, body size, and their fundamental habitat preferences. We will discuss how these results could help explain the distribution of grazer diversity in seagrass ecosystems.
Marshman, B.C.1,2*, Byron, S.N.1,2, Moore, J.D.1,2,3
ABALONE RX: DEVELOPING AN ANTIBIOTIC BATH PROTOCOL TO CURE WITHERING SYNDROME IN CAPTIVE ABALONE POPULATIONS
1 – California Department of Fish and Wildlife, 2 – Bodega Marine Laboratory, 3 – Wildlife Health Center, University of California, Davis
The future of California’s abalone species is uncertain. All of the seven native abalone species have experienced population declines over the better part of the last century, which can be mainly attributed to overfishing and disease. Withering Syndrome, a chronic degenerative disease caused by the rickettsiales-like prokaryote Candidatus Xenohaliotis californiensis (Xc), has been a prominent cause of this deterioration. Although this disease has had a significant impact on California’s wild abalone, it has also deleteriously affected captive abalone populations in farms, aquaria, and laboratories that contribute to recovery programs through captive breeding. To help combat the disease within captive populations, we developed an oxytetracycline (OTC) antibiotic treatment that has been shown to not only eliminate the Xc infection, but also protect treated abalone from subsequently being reinfected with Xc for up to four months post-treatment. The 21-day treatment, consisting of eight baths, has the advantage of not only administering a uniform dose to each abalone, but also allows for whole captive populations to be treated simultaneously. Due to efficacy while presenting minimal risk, we believe that the OTC bath treatment protocol can be used on captive abalone populations to aid in restoration efforts.
Less Powerpoint, more flower point: Exposing students to natural history in their own campus backyard
Santa Barbara City College
How do we introduce students to nature while working under the constraints of a one- to three-hour class taught within the confines of campus? The answer to this question may lie just beyond the doors of our buildings. Although each institution has its own unique setting and outdoor environment, all campuses have some potential to act as interactive natural history classrooms. Myriad courses can be enriched by use of plants, water sources, hillsides, rock walls, and other natural (or even semi-natural) features found on the college or university grounds. Whether students collect samples from outside for further examination in the lab, or take measurements and make observations “in the field”, seeing physical and biological elements of the ecosystem first-hand has a lasting imprint. I will discuss some methods currently being used to draw students into the natural environment on campus at Santa Barbara City College, as well as the potential to create on-campus environments that function as outdoor classrooms.
† McCollum, B.A.*, Edwards, M.S.
RETURN OF THE MAC: DIFFERENTIAL SURVIVAL AMONG EARLY LIFE-HISTORY STAGES AND YOUNG RECRUITS OF MACROCYSTIS PYRIFERA
San Diego State University
Many field-based studies of macroalgae focus on large conspicuous sporophytes, thereby ignoring the possible effects of ecological processes on the difficult to identify early life-history stages. This is particularly true for the giant kelp, Macrocystis pyrifera, a major ecosystem engineer and the dominant canopy-forming alga along the coast of southern California. The majority of field-based studies on M. pyrifera are limited to a single life history stage or are otherwise done over short time scales. This study tracks the survival of three different size classes of juvenile M. pyrifera (gametophytes, 5-25cm-tall, and 1m-tall sporophytes) when outplanted to the Point Loma kelp forest, San Diego, CA, at low, medium, and high densities. We compared the survival of these individuals to those of unmanipulated naturally occurring recruits. With this study, we ultimately examine size-specific variation in survival and the effects of density-dependent mortality in the early life-history stages of M. pyrifera.
† McCormick, M.C.1*, Garza C.D.1, Litvin, S.Y.2
INTERTIDAL FORAGING HABITS OF FISHED AND PROTECTED CALIFORNIA SPINY LOBSTERS OF CATALINA ISLAND, CALIFORNIA
1 – California State University, Monterey Bay, 2 – Hopkins Marine Station, Stanford University
Managers increasingly utilize marine reserves to protect valuable species like the California Spiny Lobster (Panulirus interruptus). Both in and external to these protected areas, rocky intertidal zone likely serve as an important nighttime high tide foraging habitat for lobsters, where they feed upon mussels, crabs, and limpets. On Catalina Island, variation in the prey lobsters target may reflect variable prey availability or fishing pressure. We compared the trophic level of protected and fished lobster populations by measuring their isotopic signatures. In addition, we inferred the relative importance of each of three species that largely comprise spiny lobster diet in this region by applying the isotopic signature data to Bayesian mixing models. Mixing models may indicate variation in the order of importance of prey species between fished and protected sites and between sites with and without mussel beds, a key foraging habitat for lobsters. The strategy of closing areas to fishing can impact local trophic dynamics but habitat quality, regardless of fishing pressure, remains an important factor in determining prey availability and community trophic dynamics. For coastal management, this study highlights the value of incorporating a variety of habitats, such as intertidal mussel bed habitat, into the design of marine reserves.
McCormick, T.B.1*, Buckley, L.M.2
NATIVE OYSTER RESTORATION IN MUGU LAGOON
1 – Channel Islands Marine Resource Institute, 2 – University of the Virgin Islands
To expand remnant populations of the Native Oyster, Ostrea lurida in Mugu Lagoon, Ventura County, California, six fabricated spat substrates were deployed: wire-mesh shell Trays; Mini-reefs of shell in three wire mesh bags stacked in a pyramid; Stick arrays of 36 wooden stakes covered in cemented lime granules; Futons, single layer of shell between two layers of wire mesh; Monoliths, partially buried limestone paving stones; and plastic-mesh Bags of shell suspended from a stake. Mini-reefs and Bags had the highest recruitment (621 oysters on 120.1 m2 of substrate in 2012 and 894 oysters on 89 m2 in 2013). Recruits to Mini-reefs attained average shell lengths of 24.2 mm after 9-11 months in 2012 and 38.2 mm in 2013. Nine suspended Bags produced 272 oysters; whereas, five arrays of 36 Sticks produced only 29 oysters. No recruitment was observed on 10 Monoliths. Futons became buried after several months, as did lower shells of Mini-reefs. These results estimate an increase in native oyster population in Mugu Lagoon of 11-15 percent in the first year and 14-18 percent in 2013.
† McIlroy, S.E.1*, Cunning, R.2, Gilette, P.2, Kluter, A.1, Baker, A.C.2, Coffroth, M.A.1
SYMBIODINIUM IDENTITY AFFECTS GROWTH AND THERMAL TOLERANCE IN NEWLY SETTLED ORBICELLA FAVEOLATA
1 – University at Buffalo, 2 – Rosenstiel School of Marine and Atmospheric Science, University of Miami
The majority of stony corals exist in an obligate mutualistic relationship with intracellular dinoflagellates of the genus Symbiodinium. These algal symbionts are quite diverse both taxonomically and physiologically. To determine if symbiont type affects growth and thermal tolerance of newly settledOrbicella faveolata, aposymbiotic larvae were inoculated with either S. minutum (Clade B, ITS type B1) or S. microadriaticum (Clade A, ITS type A1). The results demonstrate that these Symbiodinium species have unique photosynthetic characteristics as measured with PAM Fluorometry, and these characteristics correlate with a significant difference in coral growth over the first nine months after settlement. During this time O. faveolata polyps that harbored Symbiodinium microadriaticum (A1) grew significantly more than those with S. minutum (B1). Monthly measurements of Fv/Fm demonstrate that despite higher growth, polyps that harbored S. microadriaticum used light less efficiently than polyps that harbored S. minutum, suggesting that the former contribute more to host growth using less light. This is particularly important for researchers that correlate Fv/Fm values with host “fitness” measures. When subjected to thermal stress, there were significant differences between the photosynthetic responses to increased temperatures but the small magnitude of these differences indicate photoacclimation, rather than damage to photosynthetic organelles.
Miller L.P.1*, Allen, B.J.2, Denny, M.W.1
CHANGING ENVIRONMENTAL VARIABILITY IN A CHANGING CLIMATE: EFFECTS OF THERMAL VARIATION ON GROWTH RATES IN AN INTERTIDAL COMMUNITY
1 – Hopkins Marine Station, Stanford University, 2 – California State University, Long Beach
Climate change will involve more than just shifts in average temperature through time. Temperature variation is expected to increase in many regions, including increases in the frequency and duration of heat waves. Research on climate warming typically focuses on changes in average temperature, but changing variation in an already highly-variable environment such as the rocky intertidal zone may adversely impact many species, particularly those already living near their physiological tolerance limits. Using a novel experimental design to passively manipulate temperatures at our Central California field site, we are exploring how altered temperature variation affects the growth of herbivorous limpets and their microalgal food supply. Intensive sampling of microhabitat thermal conditions, coupled with estimates of energetic costs for limpets under varying temperatures, allows us to estimate the effects of changing environmental variability on the growth and survival of four species of limpets that have distinct microhabitat preferences and thermal tolerance limits.
† Mor, C.1*, Langdon, C.2, Carpenter, R.C.1
ELEVATED CO2 AND TEMPERATURE CAUSED BY OCEAN ACIDIFICATION AND CLIMATE CHANGE CAN DISTRESS THE PROCESSES OF PHOTOSYNTHESIS AND CALCIFICATION IN HALIMEDA INCRASSTA
1 – California State University Northridge, 2 – Rosenstiel School of Marine and Atmospheric Science,University of Miami
Climate change and ocean acidification are predicted to have negative effects on calcified organisms. It is predicted that by the year 2100, levels of CO2 will generate an unbalanced ion concentration in seawater chemistry that will disturb the calcification rates of calcifying organisms such as the green alga Halimeda,which is major carbonate producer that contributes to much of the sediments associated with coral reefs. The effects of OA and temperature on the photosynthesis and calcification of Halimeda incrassata were tested with O2 incubations, total alkalinity anomaly, and chlorophyll a and b spectrophotometric analysis through a combination of two PCO2 (390 and 900 uatm) and two temperature (26 and 30 °C) treatments. The synergistic effect of elevated CO2 and temperature destabilized photosynthesis and calcification in H. incrassata. There was a significant effect of elevated CO2 on chlorophyll b content, and a significant combined effect of temperature and CO2 on chlorophyll a content. Heat damage caused by long-term exposure to elevated temperatures may disrupt photosystem II causing a decline in photosynthesis and pigment concentrations that consequently could lead to a decline in calcification. These results suggest that growth rates of H. incrassata will be lower in a warmer and more acidic future ocean and that sediment production likely will be reduced.
† Morello, S.L.*, Etter, R.J.
TRANSITION PROBABILITIES IDENTIFY SHIFTS IN INTERTIDAL SPECIES INTERACTIONS ACROSS LARGE-SCALE GRADIENTS IN THE GULF OF MAINE
University of Massachusetts, Boston
Large-scale environmental gradients modulate ecological interactions and dramatically alter the assembly, structure, and function of communities. Understanding the role of larger-scale processes is critical for forecasting effects of climate change and managing ecosystems, but is made challenging by complex webs of species interactions. In the Gulf of Mane (GOM) intertidal, local and regional gradients in temperature, wave-exposure, productivity, and physical oceanography influence physiology and the interactions between sessile invertebrates, marine algae, and their mobile consumers. Less understood are the mechanisms responsible for regional shifts in intertidal assemblages. One approach to identify the forces regulating communities, while retaining the complexity of interactions, is to use transition probabilities among species occupying space (e.g. Markov Chain Models). Although not mechanistic, these models identify the relative importance of species interactions in community structure and dynamics, and can be used to understand how interaction webs are altered across regional scales. Transition probabilities of faunal elements were quantified monthly for 1.5 years for local intertidal communities at three replicate sites in southern, mid-coast and northern GOM. Transition probabilities differed regionally suggesting species interactions shifted in response to large-scale environmental gradients. Transitions responsible for regional differences were identified and used to infer important direct and indirect interactions.
Morgan, S.G.1*, Shanks, A.2, MacMahan, J.3, Reniers, A.4, Fujimori, F.4, Marley, J.2, Griesemer, C.1, Brown, J.2
DIFFERENTIAL TRANSPORT ACROSS THE SURF ZONE OF REFLECTIVE AND DISSIPATIVE SHORES AS A DETERMINANT OF LARVAL SUPPLY
1 – Bodega Marine Laboratory, UC Davis
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 was abundant only on the dissipative beach. Individual-based models indicated that benthic streaming and Stokes Drift coupled with sinking in turbulence may enable larvae to cross the surf zone. Different hydrodynamics of surf zones at dissipative and reflective beaches together with larval behavior may play a key role in regulating larval supply along the West Coast.
INTERIOR SECRETS OF TINY ANIMALS: MICRON-LEVEL, THREE-DIMENSIONAL INSIGHTS INTO OSTRACOD VISION, REPRODUCTION AND LUMINESCENCE
Cornell University and Shoals Marine Lab
Ostracods are tiny, abundant aquatic crustaceans, a few of which can produce light and some even participate in elaborate courtship displays at the edge of twilight over shallow habitats in the Caribbean Sea. These species have complex copulatory limbs used in internal fertilization, bilateral compound eyes, and a unique organ on the upper lip from which luminescence is secreted. Ostracod anatomy is well known from light and both transmission and scanning electron microscopy. However, nanoCT imaging on undisturbed preserved specimens is now providing detailed three dimensional insights of soft tissues to a resolution of less than a micrometer. We are focusing on (1) the structural relations among the constituents of the luminescent system and the surrounding exoskeleton and muscles of the light organ, (2) the spatial relationship of the components of the male spermatophore and its depositional state in the female reproductive tract, and (3) the optical geometry of the paired compound eyes.
† Morton, D.N.*
WHAT IS THE PARASITIC COMPONENT OF KELP FOREST BIODIVERSITY?
University of California, Santa Barbara
The parasitic component of biodiversity has only been quantified in a handful of ecosystems, and in those systems, parasites impact energy flow, food web stability, and connectance. I hypothesized that parasites comprise a large, unquantified component of kelp forest diversity. As a preliminary investigation, I used a published food web of the Santa Barbara Channel kelp forests and conducted a systematic database search to assess potential parasite diversity. The majority of parasite records were for commercially exploited fishes, with sparse data for most fishes and invertebrates. Fishes are the most resolved taxon, with 50 species in the food web. For those 50 hosts, 295 parasites have been reported in the literature. Simply adding these fish parasites would more than double the size of the kelp forest web. The number of recorded parasites per host increased with the number of publications for that host. Had all fishes been well studied, we would expect to see further parasites reported. Only field work will indicate the proportion of those reported fish parasites that will be found in a particular location. Thus, I plan to sample directly, with attention to benthic web components and identification of intermediate hosts for the parasites of the fishes.
Muth, A.F.1*, Fox, M.D.1,2, Graham, M.H.1
GROWTH VERSUS REPRODUCTION TRADEOFFS IN THE INTERTIDAL KELPS POSTELSIA PALMAEFORMIS ANDALARIA MARGINATA
1 – Moss Landing Marine Laboratories, 2 – Scripps Institution of Oceanography
Tradeoffs in resource allocation towards reproduction and growth are common in kelps. Among the 4 kelp families, the temporal aspect of these tradeoffs in response to biomass loss may be defined by their life history strategy. In this study, we tested the effects of biomass loss on growth and reproduction in the annual intertidal kelps Postelsia palmaeformis and Alaria marginata. Experiments were conducted in 2002 at Bodega Marine Laboratories (BML) and in 2011 at Soberanes Point, central California, and consisted of removing vegetative blades and quantifying subsequent growth and reproductive output. The response of Postelsia individuals to biomass loss was variable and temporary, with uncut blades at BML increasing in growth relative to cut blades, whereas those at Soberanes Point showed no growth response to biomass loss; a general short-term decline in reproductive output was observed, although all individuals quickly recovered to control conditions. Conversely, Alaria marginata was unable to regrow lost biomass and subsequently experienced a long-term crash in reproductive output. These experiments suggest that all kelps will not respond equally to disturbance, and that the ability to recover from biomass loss will be dictated by life history strategies that should be considered when investigating responses to changing environmental conditions.
NATURE EDUCATION IN OUR BACKYARD: ORMOND BEACH AS A DEGRADED AND HIDDEN OPPORTUNITY
California Sea Grant
Initiated in 2008, the Research and Education for Students and Teachers about the Ormond Beach Restoration (RESTOR) Project is a middle school teacher and student watershed education program focused on the Ormond Beach wetland in Oxnard, California. This yearlong project uses hands-on classroom and outdoor education activities to educate local middle school teachers and students about wetlands and watersheds. We attempt to use a tiered-mentoring approach to involve students in research along with community members and local university students. Most of the resident low-income, multicultural population is unaware of the expansive natural resources at their doorstep. Broader goals of the project are to foster social-ecological resilience and garner community support for the large restoration effort.
† Needles, L.A.1,2*, Gosnell, J.S.2, Waltz, G.T.1, Wendt, D.E.1, Gaines, S.D.2
Native generalist predators facilitate invasion of the introduced bryozoan Watersipora subtorquata in a marine fouling community
1 – Cal Poly San Luis Obispo, 2 – University of California Santa Barbara
Recent research has demonstrated that generalist predators can provide biotic resistance to invasion. However, predators structure communities in many ways, and theory predicts that they should also facilitate invasions through indirect interactions. We studied direct and indirect interactions of key rocky reef species of the California coast – two keystone predators; Pisaster spp. (sea stars) and Enhydra lutris nereis (the Southern Sea Otter), and two foundation species; Mytilus californianus (native mussels) and the invasive exotic bryozoan Watersipora subtorquata, a putative competitor with mussels. Both predators were found to facilitate invasion of the exotic bryozoan, and the rate of invasion was highest when both predators were present. Facilitation of Watersipora subtorquata occurred via indirect mechanisms that partly involved the removal of a competitor (mussels) via predation.
Wave exposure influences plant species richness on small islands
Quest University Canada and Bamfield Marine Sciences Centre
Species richness generally increases with sampling area. However, the species-area relationship can break down at small spatial scales, something known as the small-island effect (SIE). Here I report the results of student-led research linking intertidal zonation patterns with island biogeography theory to test a novel explanation for the small island effect. In a three-week field course, students were first presented with a research question and taught the background necessary to understand its significance. They then spent the remaining two-thirds of the course learning to identify island plants, designing a sampling scheme, collecting and analyzing the relevant data, and presenting their findings in a mock poster session. To reliably quantify species richness, students learned to distinguish one species from another through careful observation, gaining valuable natural history skills in the process. By avoiding estimates of species abundance, students were able to collect a large-enough sample to provide a reliable test of their hypothesis. Students found evidence that wave exposure can act to override the effect of island area on small islands, a novel result that could explain the presence of SIEs in many island datasets.
† Newcomb, L.A.1,2*, Hall-Spencer, J.M.3, Milazzo, M.4, Carrington, E.1,2
MECHANICAL CONSEQUENCES OF DECREASED CALCIFICATION IN THE GREEN ALGA ACETABULARIA ACETABULUM DUE TO ELEVATED CO2
1 – Friday Harbor Laboratories, 2 – University of Washington, 3 – University of Plymouth, 4 – University of Palermo
Ocean acidification lowers the saturation state of carbonate causing decreased calcification in many species. Some organisms manage to survive with much less calcification at low carbonate saturation but it is not yet clear how reduced calcification affects their performance. For calcifying marine algae, such as the green alga Acetabularia acetabulum, calcification of the stem may provide structure and rigidity to keep the organism upright. We tested the hypothesis that increases in CO2 concentration due to ocean acidification will have structural consequences by decreasing algal stiffness through a decrease in calcification. Samples were collected along a natural CO2 gradient created by volcanic vents off the coast of Isola Vulcano, NE Sicily, Italy. Both preserved and live samples were tested for percent calcification, stiffness, and critical stress load. Percent calcification was reduced at high CO2 levels by about 10%. Stiffness was reduced by about 45% at mid and high CO2 levels, suggesting a non-linear relationship between degree of calcification and mechanical performance. SEM photographs reveal erosion of the calcified matrix at mid and high CO2 levels. These eroded areas may concentrate stress potentially explaining this reduction in stiffness. Thus while A. acetabulum persists in high CO2 conditions, it is mechanically weakened by acidification.
† Nguyen, T.T.1*, Burnaford, J.L.2, Henderson, S.Y.3
EFFECTS OF LOW TIDE EXPOSURE ON THE PHOTOSYNTHETIC HEALTH OF SACCHARINA SESSILIS
1 – University of Washing Friday Harbor Laboratories, 2 – California State University Fullerton, 3 – Cerritos College
Because the canopy-forming kelp Saccharina sessilis is important in structuring Pacific Northwest rocky intertidal systems, changes in individual performance can have community-level consequences. Previous work has shown that high light and desiccation can reduce macroalgal photosynthetic health. We hypothesized that repeated exposure to stressful low tides (high light, wind, and temperature) would incrementally reduce S. sessilis health because the alga would not be able to recover between low tides, and that accumulated physiological damage would lead to visible tissue damage and biomass loss. On San Juan Island (WA) we followed six high S. sessilis thalli (+1.9ft tidal height) and six lower thalli (~ 0.0 ft). We measured dark-adapted Maximum Quantum Yield (MQY) via pulse-amplitude-modulated fluorometry to assess photosynthetic potential, assessed tissue damage by quantifying the proportion of blade area in five color categories, and evaluated biomass loss by measuring blade length. Performance of all individuals declined throughout a stressful tide series with substantial reductions in starting MQY values on subsequent days. MQY decline was accompanied by visible tissue damage and biomass loss as predicted. As biomass loss may limit individual growth and reproductive output, understanding the effects of ambient stresses will aid predictions of population parameters over longer time scales.
† Nichols, T.A.1*, Anderson, T.W.1, Širović, A.2
PHYSIOLOGICAL EFFECTS OF BOAT NOISE ON A COASTAL MARINE FISH
1 – San Diego State University, 2 – Scripps Institution of Oceanography
Boat engine noise is the most common form of noise pollution in marine environments, yet its effects on marine organisms are poorly understood. Here we investigate the stress response of a coastal fish, the giant kelpfish (Heterostichus rostratus), to boat noise with different temporal patterns and intensities. Juvenile fish were exposed to three types of boat noise in laboratory aquaria: continuous, regular intermittent, and random intermittent. Cortisol concentrations were measured and compared to those of fish exposed to continuous natural ambient sound. The random intermittent treatment elicited the highest cortisol levels of all treatments. To determine how intensity (decibels) may influence the stress response, fish in aquaria were exposed to random intermittent boat noise recorded at several distances from the hydrophone. Cortisol concentrations exhibited a non-linear decrease with increasing distance, dropping markedly in response to recordings made at greater distances. This is the first study of which we are aware that demonstrates that the temporal pattern of a noise stressor is an important determinant of a stress response, and that there may be a threshold response with distance from a noise source. We plan to examine whether stress from boat noise may have ecological consequences through differential predation risk.
Nickols, K.J.1*, Koweek, D.2, Lummis, S.1, Litvin, S.Y.1, Dunbar, R.B.2, Mucciarone, D.A.2
ESTABLISHING THE NATURAL VARIABILITY OF CARBON SYSTEM PARAMETERS AND WATER MASS PROPERTIES WITHIN KELP FORESTS
1 – Hopkins Marine Station, Stanford University, 2 – Stanford University
Kelp forests are among the most productive ecosystems, yet little is known about their biogeochemistry. Quantifying the natural physical and biogeochemical variability associated with these ecosystems is the first step in trying to understand how they may respond to global climate change and ocean acidification. We present a weekly time-series of water column properties (temperature, salinity, total alkalinity (TA), and dissolved inorganic carbon (DIC)) within and around a Central California kelp forest. During the study period (July 2013-present), Conductivity, Temperature, Depth (CTD) casts and coupled water samples revealed strong temporal variability in water column structure and spatial gradients between sampling locations inside and outside of the kelp forest. The water column ranged from stratified to well-mixed based on vertical density profiles. Stratification contributed to strong vertical gradients in carbon system parameters (ΔDIC > 200 μmol/kg and ΔTA > 40 μmol/kg), which were generally highest outside of the kelp where stratification was strongest, with temperature gradients up to five times greater than inside the forest. Carbon system variability was dominated by changes in DIC relative to changes in TA, indicative of an ecosystem dominated by photosynthesis.
Nielsen, K.J.1*, Dugan, J.E.2, Morgan, S.G.3
COMMUNITY STRUCTURE, TROPHIC LINKS AND ECOSYSTEM CONNECTIVITY OF LONG VS. POCKET BEACHES ALONG CALIFORNIA’S NORTH-CENTRAL COAST
1 – Sonoma State University, 2 – Marine Science Institute, University of California, Santa Barbara, 3 – Bodega Marine Laboratory, University of California, Davis
Trophic subsidies of macrophyte wrack influence the abundance and species richness of wrack- associated invertebrates and the abundance of shorebirds that feed on them on southern California beaches. We hypothesized macrophyte wrack would have similar effects on north-central California beaches and used this as a conceptual framework for baseline MPA monitoring. We surveyed the seasonal abundances and taxonomic composition of macrophyte wrack and birds and did a single survey of macroinvertebrate abundance and diversity on five MPA and five reference beaches. Of these 10 beaches, six were long and four were pocket beaches. However, our understanding of sandy beach ecology is based on work done on long beaches. Kelp wrack and wrack-associated invertebrates were more abundant on pocket beaches, while total macroinvertebrate biomass and species richness were correlated with the abundance of shorebirds across all beach types. Terrestrial birds (including Ravens, American Crows, Black Phoebes and Brewer’s Blackbirds) were more tightly linked to pocket than long beaches and shorebirds (including Sanderlings, Marbled Godwits, Willets and Western Snowy Plovers) were less frequently observed on pocket beaches. Our results suggest different ecological processes and ecosystem linkages drive community structure and habitat use of long versus pocket beaches along California’s north-central coast.
† Okamoto, D.K.*, Schmitt, R.J., Holbrook, S.J.
FOOD SUPPLY, DENSITY DEPENDENCE AND THE DYNAMICS OF SURVIVAL IN A TEMPERATE MARINE FISH
Ecology, Evolution and Marine Biology, University of California, Santa Barbara
The traditional paradigm for marine fishes is that adult survival typically is independent of food availability and that population fluctuations are driven predominantly by recruitment dynamics. We challenged the assumption that adult survival is independent of the availability of food resources or density with a stage-structured dataset of black surfperch (Embiotoca jacksoni). Using a Bayesian, state-space modeling approach, we find strong evidence that adult survival is regulated by both food supply and fish density. Analysis and simulation illustrate that food-mediated density dependence has substantial impacts on the expected behavior of populations with respect to both mean density and variability. The effect size of resource-driven variation in survival on population variability rivals that from recruitment variation; moreover density dependent adult survival dampens the impact of stochastic recruitment variability. Results suggest that variable food supply may contribute significantly to population fluctuations by regulating both recruitment and compensatory adult survival simultaneously.
† Olson, A.O.1*, Trebilco, R.1,2, Drake, M.1, Salomon, A.K.1
ROCKFISH ISOTOPIC NICHE WIDTH INCREASES WITHIN A PARTIALLY ‐ PROTECTED MARINE RESERVE
1 – School of Resource and Environmental Management, Simon Fraser University, 2 – Department of Biology, Simon Fraser University
Although marine reserves are often established with the goal of protecting marine ecosystems from anthropogenic pressures (e.g. overfishing), their effects on ecosystem processes are rarely measured. We tested the effects of spatial protection on rockfish density, size, biomass and isotopic niche width off Haida Gwaii, an archipelago of islands located off the north coast of British Columbia, Canada. We sampled rockfish (Sebastes spp.) within replicate rocky reef sites nested within two fished areas and a 5‐yr old Rockfish Conservation Area (RCAs), a marine reserve designation that prohibits hook and line fishing for reef‐associated fish. Stomach contents provided a snap shot of fish diets, while δ15N and δ13C signatures of muscle tissue and Bayesian ellipses provided estimates of integrated niche width. We found that rockfish niche width was larger in the RCA relative to fished areas and that this increase was driven by enriched δ15N values. δ13C values did not significantly different between areas. Surprisingly, the density and biomass of fish communities obtained from dive surveys did not differ between fished and non‐fished areas, suggesting that the earliest detectable effects of spatial protection may manifest in trophic rather than numerical responses.
† Orr, D.W.*, Garza, C.
PREDICTIVE MODELING OF WAVE FORCE AND ITS DISTRIBUTION OVER A ROCKY INTERTIDAL LANDSCAPE
California State University Monterey Bay
Disturbance is known to play an important role in structuring communities. Understanding and predicting small scale disturbance by large scale environmental forces has important implications for natural resource management and understanding potential consequences resulting from climate change. This is particularly important when considering disturbance to the foundation species within a community such as coral reefs or large trees in a forest. The California mussel, Mytilus californianus, is a sessile foundation species that forms massive aggregations along rocky shores in the North Eastern Pacific. In rocky intertidal communities waves are assumed to play an important role in disturbance and structuring the distribution of species. Here we measure wave force across a rocky intertidal using a swath of dynamometers. Coordinates and elevation were measured across each site. GIS modeling was used to characterize and quantify landscape characteristics. These data were used to develop a model to predict the distribution of wave force across an intertidal landscape. Understanding and predicting small scale disturbance from large scale environmental forces would have implications on other communities that depend upon foundation species. This has important implications regarding climate change, natural resource and ecosystem management.
Paddack, M.J.1,2*,Crane, N.L.1,3, Bernardi, G.4, Abelson, A.5, Nelson, P.6, Precoda, K1
ECHOES OF PRESENT & PAST HUMAN PRESENCE ON CORAL REEF COMMUNITIES 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 – CFR-West
Despite relatively low human population sizes in Ulithi Atoll, Micronesia, concern is mounting over declining fish stocks and coral reef health, upon which the villages are dependent for food and traditional ceremonies. In 2012, we began working with the villages to help assess the state of their resources and craft a sustainable marine resource use plan incorporating knowledge and engagement of community members into ecological assessment, monitoring and management. Our surveys of reefs throughout the atoll over two years reveal strong differences among Ulithian reefs in abundance, diversity, and population structure of fishes and corals and structural complexity. There are indications that degradation in coral reef health is related to proximity to present and past history of human population size on these islands. We are mapping, genetically identifying, and tracking two different species outbreaks – a coral and a corallimorph. We have found these outbreaks only in landings and anchorages. Actions taken by the most populated island, Falalop, limiting some or all types of fishing on their reefs in 2012 appear to have started a process of protection from continued decline relative to other reefs.
† Paterson, C.N.*, Allen, L.G.
THE GENETIC DIVERSITY AND POPULATION STRUCTURE OF BARRED SAND BASS (PARALABRAX NEBULIFER)
California State University, Northridge
Barred sand bass (commonly, sand bass), Paralabrax nebulifer, is part of the largest recreational fishery in southern California as well as a large artisanal fishery in Mexico. This species ranges from Santa Cruz, California to the southern tip of Baja California, Mexico, but is common only south of Pt. Conception. Sand bass form large spawning aggregation in the summer months of June-August which makes them highly susceptible to overfishing. In the last decade, populations of sand bass in southern California have experienced a severe decline in numbers and subsequently the recreational fishery has been seriously impacted. A severe decline in numbers can lead to a decrease in genetic diversity and to a genetic bottleneck. The population structure and genetic diversity of barred sand bass populations was previously unknown. This study looks at both using the d-loop region of the mitochondrial DNA for populations in California and Mexico. There is no evidence of genetic structure or low genetic diversity across the entire range of barred sand bass. Instead there is high connectivity and diversity indicative of panmixia across the region.
† Peterson, M.G.*, Hunt, L., Resh, V.H.
BENTHIC MACROINVERTEBRATE COMMUNITY RESPONSES TO A DIESEL OIL SPILL IN AN URBAN, MEDITERRANEAN STREAM
University of California, Berkeley
Among anthropogenic stressors to urban streams, exposure to chemical contaminants can cause both short- and long-term impairment to aquatic communities. The impacts of episodic spills can be difficult to assess due to the seasonal fluctuations stream community structure. Using a Before-After-Control-Impact (BACI) experimental design we examined community-level effects in macroinvertebrate fauna downstream of an unintentional 500 gallon diesel spill in the northern fork of Strawberry Creek, an urban Mediterranean-climate stream in California. Benthic macroinvertebrates were sampled monthly at four sites within the two-fork system for fourteen months pre- and post-spill, which allowed for analyses to incorporate seasonal variability. At three days post-spill, the percent of Ephemeroptera, Plecoptera, and Trichoptera (%EPT) in the impacted macroinvertebrate community was reduced by 90% compared with pre-spill levels; meanwhile, upstream control sites remained similar pre- and post-spill. Community diversity metrics, species richness, and % EPT increased to pre-spill levels after three months. One year post-spill, community metrics were comparable with pre-spill seasonal conditions, suggesting community-level recovery. The re-colonization of sensitive EPT taxa in the impacted community may have been facilitated by drift from the unaffected southern fork of Strawberry Creek, suggesting that multiple-fork complexity may promote resilience to acute spills in urban systems.
† Peterson, S.1*, Ackerman, J.2, Costa, D.1
FORAGING ECOLOGY INFLUENCES MERCURY IN DEEP-DIVING ELEPHANT SEALS
1 – University of California, Santa Cruz, 2 – U.S. Geological Survey, Western Ecological Research Center
Northern elephant seals (Mirounga angustirostris) travel across the northeastern Pacific Ocean during their biannual migrations, foraging in mesopelagic (200-1000 m depth) coastal and open-ocean regions. Although little is known about mercury in mesopelagic food webs, we know that mercury is more bioavailable in this zone due to marine chemistry. Elephant seals forage exclusively in this habitat and thus are potentially exposed to higher mercury concentrations than shallower-diving species. Blood, muscle, and fur were sampled from adult females and males during 2010-2013 and analyzed for total mercury (THg). For adult females, we used satellite tags and time-depth recorders to examine relationships between mercury concentrations and age, mean dive depths of day and night foraging dives, stable isotopes (nitrogen and carbon), oceanic ecoregions, and distance to the continental slope, in order to quantify how foraging ecology may influence mercury concentrations. Total mercury in seal muscle ranged from 1.2-13.8 µg/g (dry weight) and in fur from 6.0-75.3 µg/g, which are among the highest concentrations observed in non-stranded marine predators. Our results indicate that mesopelagic marine predators may be at greater risk for mercury accumulation than previously assumed and provide insight into the potential for mercury bioaccumulation in more elusive and vulnerable species.
† Piacenza, S.E.H.1*, Balazs, G.H.2, Hargrove, S.A.3, Richards, P.M.3, Heppell, S.S.1
Temporal variability of vital rates for a recovering population of green sea turtles (Chelonia mydas): potential indicators for population recovery?
1 – Oregon State University, 2 – Pacific Islands Fishery Science Center, 3 – Southeast Fishery Science Center
Populations undergoing recovery are dynamic and unstable. Green sea turtles, Chelonia mydas, have shown remarkable recovery in the Hawaiian Islands, with an estimated annual growth rate of 5.7%, but with wide annual fluctuations in nester abundance. This makes estimates of population size particularly difficult, and the National Research Council has recommended additional demographic research to understand how life history traits vary over time and potential indicators of density dependence. We are evaluating two life history traits in tagged Hawaiian green turtles: breeding interval and size of nesters (straight carapace length, SCL). We used generalized linear mixed models to analyze the traits from 1973 to 2010. Year was an influential factor for both life history traits. Breeding interval ranged from 1.99 (0.95 – 4.22 95% CI) to 4.68 (4.40 – 4.97 95% CI) years. Nester SCL ranged from 89.21 (88.97 – 89.46 95% CI) to 91.69 (91.50 – 91.88 95% CI) cm. There is evidence of a non-linear relationship between nester abundance and these traits. This is the first investigation of temporal variability in these traits for the Hawaiian population, and our results will contribute to a population model to assess recovery rate and impacts of future management strategies.
Pondella, D.J.*, Claisse, J.T., Williams J.P.,Zahn, L.A., Williams. C.M.
FISH PRODUCTION, HABITAT RESTORATION AND CONSERVATION ON THE PALOS VERDES PENINSULA
Vantuna Research Group, Occidental College
The Vantuna Research Group has been tracking the fish populations on the Palos Verdes Peninsula continually since 1974. In 1988 we began a biological assessment of the Abalone Cove and Portuguese Bend marine habitats and this research program now encompasses the entire nearshore reef system on the PV Shelf. We are currently using data products from this intensive study to model artificial reef design and placement to maximize fish production, habitat conservation and reef restoration on the PV Shelf.
Price, N. N.*, Martz, T. R., Smith, J.E.
DO CALCIFIED ALGAE ACCLIMATE TO DIEL FLUCTUATIONS IN SEAWATER pH ON CORAL REEFS?
Scripps Institution of Oceanography, University of California San Diego
Recent advances in autonomous sensor technology have expanded our appreciation for the spatio-temporal complexity of carbonate system dynamics in coastal environments, particularly on coral reefs. The physiological consequences for reef organisms frequently experiencing chemical conditions corrosive to carbonate minerals (approaching IPCC ocean acidification [OA] projections for the next century) are unclear. Ecologically important benthic seaweeds, which cement coral reefs and are an important food resource, may respond to dynamic inorganic carbon diel cycling. By co-locating autonomous pH/T sensors across 10 sites with long-term (>5 yrs) monitoring plots and transplanted specimens of calcified algae, we demonstrate that calcification rates and relative abundances of coralline algae and Halimeda spp. are positively correlated with the least variable chemical conditions. Additionally, we explore the response of a green calcified alga, Halimeda opuntia, to simulated OA using reciprocal transplant and common garden experiments and discover that biomineralization in these seaweeds is relatively unaffected by high pCO2 if they are previously exposed to naturally fluctuating chemical conditions. Our results indicate that exposure to suboptimal conditions in situ can slow calcification rates of reef-builders, but the same diel variation may acclimatize organisms to projected acidification and reduce severity of response to traditional OA experimental treatment conditions.
† Quintana, A.C.E.*, Garcia-Vedrenne, A.E., Hechinger, R.F., Kuris, A.M.
Trematodes of the California horn snail: some have social organization with a reproductive division of labor, others do not
University of California, Santa Barbara
A reproductive division of labor is well known for some organisms, including arthropods (e.g., bees and ants), naked mole rats, and a sea anemone. Recently, comparable social organization has been documented for some parasitic trematode flatworms. Trematodes form clonal colonies within their molluscan first intermediate hosts, and some species have both reproductive and soldier castes. Reproductives are large and filled with offspring. Soldiers are small, slender, have relatively large pharynxes, and attack and kill unrelated trematodes. This reproductive division of labor has so far been documented for five trematode species from different geographic regions and host species. Here we systematically explore the trematode fauna of the California horn snail, Cerithidea californica, which is infected by 20 morphologically distinct trematode species. Social organization has been previously documented for only one species infecting this snail. Here, we report four additional species that show reproductive division of labor: Himasthla rhigedana, Parorchis acanthus, Cloacitrema michiganensis andAcanthoparyphium spinulosum. We further detail four other species that lack such a division of labor. The wide variation in social organization between trematode species infecting the California horn snail indicates that this system can be a valuable tool for research examining the ecology and evolution of social organization.
Ranelletti, M.E.*,Hernandez, V.*, Krueger, K.L.*
“THAT’S MY PROJECT” – INSIGHTS FROM HIGH SCHOOL STUDENTS AND MENTORS ON COMPLETING SUCCESSFUL INDEPENDENT PROJECTS
Santa Barbara Museum of Natural History
Independent projects are wonderful tools for getting science minded students involved in research. Independent projects often allow for students to pursue their own interests and have a sense of ownership for their work. Projects also provide opportunities for students to receive guidance from scientists or project leaders. Classrooms and outreach programs often provide these project-based independent learning and mentorship opportunities. At the Santa Barbara Museum of Natural History we have a four year science program, Quasars to Sea Stars, where the students choose an independent project for the summer of their final year. Our staff educators and scientists mentor the students. Each year there are major hurdles that our students, educators, and mentors must overcome to ensure that the students follow their interests to create a project that they can complete in the time allowed. During this talk you will hear from the program manager and two of our senior high school students. They will share their insights about what are the most important things to plan for when creating independent project opportunities for students. The students will also share a little bit from their projects: “Delve into Mission Creek” and “Bird Beak Bonanza.”
† Rasmuson, L.K.*, Shanks, A.L.
IN SITU OBSERVATIONS OF SWIMMING ORIENTATION AND SPEED OF DUNGENESS CRAB MEGALOPAE
Oregon Institute of Marine Biology
A key question in marine ecology is how the planktonic larvae of coastal organisms are transported back to settlement sites in nearshore waters. One mechanism of transport is by internal waves that are generated by internal tides. Daily recruitment of Dungeness crab megalopae to Charleston, OR is significantly correlated with the tidal cycle (though lagged relative to the spring-neap cycle) suggesting megalopae are transported by internal waves. The distance larvae are transported by internal waves increases if megalopae swim in the direction of wave propagation, and are strong swimmers. We conducted in situ observations of Dungeness crab megalopae to determine if megalopae orient their swimming to abiotic factors and to quantify their average swimming speed. To determine swimming orientation a snorkeler released megalopae and recorded the direction they swam, as well as the direction of the surface current, waves and sun. On all days, megalopae swam with the surface current. To determine swimming speeds, individual megalopae were followed for 30 seconds by a snorkeler holding a flowmeter. The average swimming speed of megalopae after the removal of background water velocity was 9.8 cm s-1. These behaviors should increase the cross-shelf transport distance of Dungeness megalopae.
Reed, D.*, Schroeter, S, Huang, D., Harrer S.
Production not attraction accounts for high macroalgal biomass on the Wheeler North Reef
University of California Santa Barbara
Debate over whether artificial reefs serve as centers of attraction vs. production have generally focused on highly mobile reef fishes. This debate may also apply to sessile organisms if artificial reefs serve as sinks for propagule dispersal. There has been little discussion to date, however, concerning the extent to which artificial reefs act as sources of production (vs. sinks for attraction) for sessile species. This is particularly true for primary producers such as macroalgae that serve as major sources of food and shelter for high trophic levels. We examined this phenomena by applying recently develop methods for estimating macroalgal biomass and net primary production (NPP) to time series data of macroalgal abundance collected at the recently constructed 71 ha Wheeler North Reef (WNR) and two adjacent natural reefs before and after the construction of WNR. Our results show: 1) macroalgal biomass and NPP at WNR rapidly increased to levels that were greater than that of nearby natural reefs, 2) the higher biomass at WNR could not be explained by the attraction of algal propagules away from natural reefs, and 3) the construction of WNR has led to a substantial increase in the macroalgal biomass of the region.
† Reimer, J.N.*, Hacker, S.D., Menge, B.A.
SOURCE AND SEASON AFFECT THE PRESENCE OF MACROPHYTE WRACK SUBSIDIES ALONG PACIFIC NORTHWEST SANDY BEACHES
Oregon State University
Macrophyte wrack, such as drift algae and seagrass, washes into coastal ecosystems from the ocean and is an important ecological resource for biological communities. This subsidy may be especially important on sandy beaches, where little in situ primary productivity exists to fuel higher trophic levels. To better understand the potential importance of macrophyte wrack as a coastal subsidy, we investigated the amount and composition of wrack that washes into Pacific Northwest sandy beaches. We conducted a large-scale observational study at 13 sites from southern Washington to northern California using two different surveys to estimate the amount and composition of wrack onshore. All sites were monitored in early and late summer to understand how temporal variability (e.g., storms and algal senescence) affects wrack presence. Our data suggest that macrophyte wrack maintains a consistent presence on all beaches throughout the summer, that proximity to a rocky headland or estuary dictate the type of wrack washed ashore, and that inputs increase later in the season. As wrack presence influences the nutrients available to coastal organisms, our next steps involve determining the nutritional value of wrack and the connections that may help deliver these nutrients to local producers and consumers in the dune ecosystem.
† Renick, V.C.1*, Vidal-Dorsch, D.2
Linking physiological and behavioral responses to pesticide exposure of an estuarine fish, Fundulus parvipinnis
1- San Diego State University and Coastal and Marine Institute, 2- Southern California Coastal Water Research Project
Estuarine and coastal ecosystems are frequently polluted by coastal cities. Pesticides are common contributors to coastal pollution, yet their ecological consequences for resident organisms are relatively understudied. The majority of studies focus on the physiological effects of sublethal pesticide exposure, but their connections to behavior and ecology are not well understood. Here, a common estuarine species, the California killifish (Fundulus parvipinnis) serves as a model to improve our understanding of the relationship between physiological and behavioral effects of sublethal pesticide exposure. Juvenile fish were exposed to a common organophosphate pesticide, chlorpyrifos, at two pesticide concentrations for four days. Subsequent behavioral observations were conducted to assess activity and exploration in a novel environment, social behavior, and the willingness to forage following a simulated avian predator attack. The activity of acetylcholinesterase, a neuromuscular enzyme, was later measured in brain and muscle tissue of each individual and related to their behavior. Our results indicate that pesticide exposure altered multiple ecological behaviors, including activity levels, surfacing behavior, sociality, and an anti-predator response. Furthermore, physiological responses as measured by altered enzyme activity were highly linked to specific behaviors. These modifications in behavior carry potential ecological consequences, including heightened predation risk.
Ridgway, L.M.1*, Foster, N.R.2, Valdes, A.A.3, Gravitt, A.4
Biogeography AND ECOLOGICAL OBSERVATIONS of Boreoberthella augusta in Pribilof Canyon and Zhemchug Canyon, Bering Sea
1 – Alaska Deep Ocean Science Institute, 2 – NRF Taxonomic Services, 3 – California State Polytechnic University , 4 – Alaska Pacific University
In 2007 live specimens and video images of an unidentified pleurobranch were collected during submarine exploration of the Pribilof and Zhemchug canyons in the Bering Sea. Expert examination of the specimen, especially the radular and jaw morphology confirmed its identity as Boreoberthella augusta. The new genus and species of this pleuobranchoidean opisthobranch, Boreoberthella augusta, was reported by Martynov and Schrodl in 2009. It was described from preserved specimens collected in the 1930s, 1971 and 1991 in the Sea of Japan and near the Komandorskyie Island in the northwestern Pacific. Our in situobservations of B. augusta provide details on morphology, coloration and ecology of the organism in subarctic undersea canyons, now considered a northern reservoir for this and other members of some pacific invertebrate fauna. We describe distribution patterns, species associations, habitat and limited behavioral attributes of this exquisite new opisthobranch.
† Rinehart, S.A. 1,2*, Guidone, M.2,3, Thornber, C.2
OVERWINTERING STRATEGIES OF ULVA SPP. IN NARRAGANSETT BAY, RI
1 – San Diego State University, 2 – University of Rhode Island, 3 – Sacred Heart University
In order to fully understand how Ulva spp. blooms begin to proliferate in the spring, we need to understand their overwintering strategies. Previous studies showed that Ulva spp. can overwinter as fragments, germlings and/or microscopic propagules. In this study we examined the winter abundance ofUlva species as fragments, germlings, and microscopic propagules at multiple bloom-impacted sites in Narragansett Bay, RI. We found that distromatic Ulva fragments were present in the water column and the sediment throughout the winter months. Density of fragments in sediment cores did not differ significantly among months or sites, indicating a relatively consistent fragment pool. Settlement tiles placed in the field for varying lengths of time contained distromatic Ulva spp., confirming their presence throughout the winter months. Tiles moved from the field and subsequently cultivated in the laboratory showed that under simulated spring conditions, Ulva spp. begin to propagate, suggesting that Ulva spp. may be overwintering as microscopic propagules. Additionally, fragments within the sediments may act as a ‘seed bank’ during years of reduced propagule recruitment. Our data give increased support to the hypothesis that bloom-forming Ulva may utilize multiple reproductive strategies, thereby increasing its chances of survival during harsh winter months.
Rivers, T.J.1*, Morin, J.G.2
THE COSTS OF LIGHT FOR ATTRACTION AND DEFENSE: LUMINESCENT CHEMICAL BUDGETS IN A CARIBBEAN OSTRACOD
1 – University of Kansas, 2 – Cornell University
In luminescent species, a single individual may use light for a variety of purposes, including courtship and defense. However, the relative costs of producing these different behaviors remain largely unknown. In the marine ostracod Photeros annecohenae, males and females have extracellular luminescent displays for predation defense. Additionally, males utilize light for complex courtship displays. We recorded and quantified the relative amounts of light released by both display types and compared them to each other and to the total stores found in the individual. We found courtship displays are inexpensive compared to defensive displays, releasing 50 times less luminescence. Males would need to display over 450 times to completely exhaust their stores. Both display types show simple first-order decay kinetics; however, courtship displays decay three times faster than defensive displays, leading us to hypothesize there is differential release of the luminescent chemicals and mucus to fine-tune the signal characteristics.
† Rivest, E.B.*, Hofmann, G.E., Blanchette, C.A., Kapsenberg, L.
Keeping a finger on the pulse of marine ecosystems: the investment of coupled long-term physical and biological observations
University of California Santa Barbara
The co-location of environmental sensors with hypothesis-driven research continues to be a significant and valuable asset towards an understanding of how environmental change might alter marine populations, communities, and ecosystems. Exemplified by the coastal and marine Long Term Ecological Research (LTER) programs, the incorporation of these sensors and measurements into core biological research frameworks facilitates the linking of environmental data with changes in biological or ecological processes. Additionally, these in situ data can guide the design and interpretation of laboratory experiments on important species, placing these studies in a relevant environmental context. Here, we focus of three key environmental parameters measured at several LTER sites: (1) air and sea temperature, (2) wave and storm energy, and (3) seawater chemistry. Each case highlights the importance of coupling long-term physical and biological observations for documenting and forecasting the impact of global change on marine coastal ecosystems that host high biodiversity and support many ecosystem services.
† Sabal, M.C.1*, Carr, M.H.1, Hayes, S.A.2, Merz, J.E.3, Setka, J.D.4
INTERACTIVE EFFECTS OF NON-NATIVE SPECIES AND HABITAT ALTERATIONS ON NATIVE JUVENILE SALMON
1 – University of California Santa Cruz, 2 – Southwest Fisheries Science Center (NMFS), 3 – Cramer Fish Sciences, 4 – East Bay Municipal Utility District
Predation is a fundamental process that structures and shapes ecosystems. Humans can intensify effects of predation on native species through introduction of non-native species and habitat alterations. In California, native salmon populations are in decline and juvenile salmon experience low survival during their outmigration where they pass through various habitat alterations and encounter non-native predators (e.g. striped bass). My study objectives were to (1) examine how striped bass consumption of juvenile salmon varies by habitat; and (2) assess population-level consumption in an area of high predation. Diet data illustrated a significant difference in frequency of occurrence of important prey items for striped bass caught at a dam (Chinook salmon 80%, crayfish 15%) and other locations (Chinook salmon 0%, crayfish 75%). Focusing on the dam habitat, population-level consumption of striped bass on juvenile salmon was examined through three separate approaches resulting in a range of impacts between 10.2% and 25%. These results show that humans are exacerbating mortality on native juvenile salmon through combined effects of a non-native predator and habitat alterations. Predators, prey, and habitat can interact to shift predation pressure; this has important implications in assessing relative potential for various management strategies for native species recovery.
Samhouri, J.F.1*, Shelton, A.O.1, Feist, B.1, Williams, G.1, Bartz, K.1, Canade, E.2, Fotherby, H.2, Sheer, M.1, Levin, P.1
HOW MUCH CITY IS TOO MUCH CITY? DIVERSITY AND ECOSYSTEM FUNCTIONS ALONG AN URBAN GRADIENT IN PUGET SOUND
1 – Conservation Biology Division, Northwest Fisheries Science Center, 2 – Program on the Environment, University of Washington
Over half of the world’s population resides in urban areas and 44% in coastal areas. As urbanization continues, the ability of coastal marine ecosystems to provide the services people want and need from them is in question. Indeed, the extent of human activity in a region often doubles as an indicator of natural ecosystem responses to multiple stressors. For instance, habitat conversion and reclamation, harvest and hunting, and human population density are frequently assumed synonymous with reductions in the abundance of wild animal populations. However, it is surprising how rarely such assumptions are actually tested against real-world observation of the relationships between stressors and components of ecosystem structure and functions. In this study we investigated how land cover, a potential indicator of stressors such as toxic contaminants, nutrient loads, and extractive uses, related to empirically measured ecosystem responses in the nearshore marine environment of Puget Sound, WA, USA. Specifically, we estimated how invertebrate diversity and four ecosystem functions (primary production, secondary production, decomposition, and predation) varied across 12 watersheds characterized by perennial streams flowing directly into Puget Sound. In addition to measuring land cover, which spanned a gradient from highly rural (>80% forested) to heavily urbanized (>80% developed), we also tracked other factors that could influence these ecosystem response variables, such as temperature, salinity, stream flow, and nutrient loads. Marine primary productivity and decomposition rates tended to be lower in more urban than less urban areas, while predation rates and diversity were largely invariant across the urban gradient. These preliminary results suggest that land cover indicators can provide useful information about changes in natural ecosystems. Because ecosystem responses can be idiosyncratic, though, this study also highlights the importance of groundtruthing stressor-ecosystem relationships to ensure that indicators are indeed meaningful.
San Miguel, R.A.1,2,3*, Neeb Wade, P.1,3, Sankaran, S.M.3
WATSONVILLE AREA TEENS CONSERVING HABITATS (WATCH): INSPIRING HIGH SCHOOL STUDENTS TO CONSERVE THEIR WATERSHED THROUGH SCIENCE
1 – Moss Landing Marine Laboratories, 2 – California State University: Monterey Bay, 3 – Monterey Bay Aquarium
The WATCH program (Watsonville Area Teens Conserving Habitats) was created through a partnership between the Monterey Bay Aquarium and the Pajaro Valley Unified School District in Watsonville, California. The program educates teens about watershed science and the importance of environmental stewardship, particularly in a region that has direct impacts on the health of the ocean. During a summer program and year-long science elective, high school students learn to craft testable scientific questions, test them in the field, analyze their data, and present their results to their community, and to relevant stakeholders through an outreach activity of their design. Local scientists from institutions such as Moss Landing Marine Laboratories, University of California at Santa Cruz, Monterey Peninsula College, the Monterey Bay Aquarium Research Institute (MBARI), California State University at Monterey Bay (CSUMB), and Elkhorn Slough National Estuarine Research Reserve mentor students throughout the school year. Collaboration between the Monterey Bay Aquarium, teachers and school administrators, City of Watsonville employees, local scientists, and community members allows WATCH to make unconventional, project & field-based science education possible in one of the most disadvantaged school districts in the state.
† Sanchez, B.D*, Steele, M.A.
IMPACT OF ORGANIC POLLUTANTS ON THE GROWTH AND FECUNDITY OF PARALABRAX NEBULIFER (BARRED SAND BASS) FROM SOUTHERN CALIFRONIA
California State University, Northridge, Department of Biology
Organic pollutants are globally distributed and persistent since they have the ability to accumulate in sediments and in the tissues of organisms. These pollutants can cause physiological stress in fishes by limiting the abilities to acquire resources for growth, reproduction, and survival. Benthic associated species are more impacted by pollutants by their direct and indirect contact with the substrate, especially in areas of high pollutant concentrations, like harbors. This study evaluated the impacts of pollutants on growth and fecundity of a recreationally important coastal marine fish in Southern California. Tissue concentrations of pollutants, as well as growth, physiological condition, and reproductive potential were compared among four sites. There was a significant difference of pollutant type and concentration among sites, with fish in harbors having the highest tissue concentrations. Measures of growth, physiological condition, and reproductive potential did not differ among sites, implying that the concentrations of pollutants in the harbors studied were not high enough to affect these variables. Organic pollutants are still present in the marine environment of Southern California, but this research indicates that the concentrations are too low to significantly impact the growth and reproductive potential of the barred sand bass population.
† Schram, M.J.*, Steele, M.A.
EFFECTS OF SIMULATED SIZE-SELECTIVE HARVESTING ON A PROTOGYNOUS TEMPERATE REEF FISH,RHINOGOBIOPS NICHOLSII
California State University, Northridge
Observational studies examining the effects of size-selective harvesting on protogynous fishes across large temporal and spatial scales have noted reductions in size at maturity and size at sex-change which ultimately may influence reproduction and future population size; however controlled, manipulative studies demonstrating the causal links have not been conducted. The purpose of this study was to investigate those direct effects using a model study species, the blackeye goby (Rhinogobiops nicholsii), occupying twenty 2.25 m2 artificial reefs subjected to size-selective removals. Five reefs each received one of three size-selective removals (large, medium and small) with the five remaining reefs as controls. Reproductive output was measured on artificial nesting plates photographed weekly for 5 weeks to quantify clutch size and egg density. Size-selective removals did not significantly affect reproductive output of the study populations, suggesting there is adequate social flexibility in reproductive patterns to buffer short-term effects of size-selective harvest. Disruption of social dominance hierarchies that repress growth of subordinate individuals may allow rapid growth of certain individuals after harvest. This growth flexibility combined with the ability to change sex may provide protogynous species the ability to replenish size classes with high reproductive value at a greater rate than can gonochoristic species.
Schroeter, S*, Reed, D., Huang, D., Weisman, D.
the Wheeler North Reef as a test case for the production vs. attraction hypothesis for reef fish
University of California Santa Barbara
Debate over whether artificial reefs serve as centers for attraction or production of reef biota, particularly for mobile reef fishes is longstanding and largely unresolved. One of the few examples of an experimental study addressing this question found evidence of production for octopus but not mobile reef fish on a large artificial reef in Japan. We present data from an analysis of a time series of fish standing stock biomass on the Wheeler North Reef (WNR) and two natural reference reefs: an impact reef near WNR (the San Mateo reef) and a control reef far away (the Barn reef). Data were collected at both the near (Impact) and far (Control) natural reefs seven years prior to the construction of the WNR and at all three reefs four years after construction. These were used to: 1) examine changes in standing stock at all three reefs before and after the construction of WNR, and 2) to conduct a BACIP analysis to examine the influence of the WNR on reef fish standing stock in the near control reef (i.e. San Mateo reef). We found that overall standing stock in the combined WNR and San Mateo reefs declined slightly from the before to the after period. In addition, the BACIP analysis showed a substantial relative decline in fish standing stock biomass at the San Mateo reef from the Before to the After period. Although ongoing studies indicate that reef fish production is occurring on WNR, the BACI results indicate substantial attraction of fish from San Mateo to WNR.
† Selden, R.L.1*, Warner, R.R.1, Gaines, S.D.2
THE CONSEQUENCES OF FISHING-INDUCED CHANGES IN PREDATOR SIZE FOR TOP-DOWN CONTROL OF PREY POPULATIONS
1 – Ecology, Evolution and Marine Biology, University of California Santa Barbara, 2 – Bren School of Environmental Science and Management, University of California Santa Barbara
Removing predators has released prey from top-down control in many ecosystems. In marine ecosystems, trophic cascades have been attributed to declines in predator abundance due to overfishing. However, fishing also truncates the size distributions of these predators. Because body size determines what a predator can eat, the loss of large individuals may eliminate the capacity of the predators to regulate prey populations, and cause similar changes as total removal. We developed a size-structured predator-prey model to examine the characteristics of predators, prey, and fisheries that make predator-prey interactions vulnerable to disruption by fishing. We applied this model to kelp forest ecosystems in which predation by sheephead, Semicossyphus pulcher, on sea urchins, Strongylocentrotus spp., depends on size. In populations where large sheephead were absent, urchin mortality rates were lower in the field, particularly on the largest urchins. In simulations, fishing sheephead, even at sustainable rates, led to a reduction in the ability of sheephead to control urchin densities, and an increase in the likelihood of an urchin barren. Given the losses in biodiversity as kelp forests are converted to urchin barrens, it will be important to consider the effects of changes in predator size on this key predator-prey interaction.
† Shantz, A.A.*, Burkepile, D.E.
WHEN THE SH*T HITS THE (SEA)FAN: IMPACT OF FISH-DERIVED NUTRIENTS ON CORAL REEF COMMUNITIES
Animals often act as vectors of nutrients, creating biogeochemical “hotspots” that play important roles in structuring communities. On coral reefs, understanding how such fish-derived subsidies impact community structure has become increasingly urgent as systemic overfishing continues to leave many reefs devoid of such subsidies. Here, we show that shoals of predatory reef fishes can create nutrient heterogeneity within a coral reef. Through selectivity in shelter sites, mesopredators from the families Haemulidae and Holocentridae created localized “hotspots” with consistently higher biomass of fish. At these high biomass sites the average nitrogen (N) and phosphorus (P) delivery was calculated to be 13.2 and 14.6 times greater than similar sites with low predatory fish biomass. These subsidies resulted in an approximate three-fold increase in the grazing rates of herbivorous fishes, presumably through increases in the nutritional value of food items. In turn, in contrast to enrichment driving increased macroalgal growth, these elevated grazing rates maintained macroalgae cover at levels equal to similar low fish-biomass sites, while significantly increasing the cover of crustose coralline algae. In addition, the skeletal extension rates of Acroporid coral transplants were significantly higher at high fish-biomass sites (0.011% day-1) than low fish-biomass sites (0.006% day-1). Taken together, our results suggest that by concentrating nutrients at specific locations, predatory fishes play an important and underappreciated role in the bottom-up structuring of coral reef communities.
† Silberg, J.N.*, Salomon, A.K.
INDIRECT EFFECTS OF SEA OTTER RECOVERY ON TEMPERATE REEF FISH
Simon Fraser University School of Resource and Environmental Management
The loss or recovery of apex predators can have profound positive or negative ecological and socio-economic impacts. Effects of predator depletion or recovery are frequently accompanied by time lags and non-linear dynamics, which are often context-dependent. In temperate rocky reef ecosystems, sea otters (Enhydra lutris) trigger a cascade of direct and indirect effects driving transitions between alternative kelp-depleted and kelp-dominated states. We quantified indirect effects of sea otter recovery on fish size structure and relative abundance along a gradient in sea otter occupation time on British Columbia’s Central Coast. We used hook-and-line surveys at shallow depths (2-25 m) at 20 rocky reef sites and a space-for-time substitution representing variation in occupation time. We found significant differences in the size of copper rockfish (Sebastes caurinus) along the otter occupancy gradient with larger fish occurring at sites with longer otter presence (p<0.001). However, we found no difference in the sizes of lingcod (Ophiodon elongatus) and other rockfish species (Sebastes spp.), or in the catch rate per unit effort for any species along the same gradient. These data will allow us to evaluate trade-offs elicited by sea otter recovery and thus advance ecosystem-based approaches to conservation and management plans for temperate reef systems.
† Simonsen, C.M.*, Sandin, S.A.
QUANITIFYING THE DRIVING FORCES OF FORAING BEHAVIOR IN HERBIVOROUS REEF FISHES
Scripps Institution of Oceanography, University of California, San Diego
Coral reefs have undergone major phase shifts in the past three decades resulting in algal dominance and herbivorous fish are the main force removing algae from Caribbean reefs. This study looks to determine the elements controlling herbivorous fish populations on Caribbean coral reefs and their ability to remove turf and erect macroalgae. We asked whether the foraging rates and behaviors at a species, family and guild level changed with context. Over a three-month period, focal observations were conducted on five common herbivorous fish species, three Scarids and two Acanthurids, at nine sites on Curaçao that varied in benthic composition and fish populations. On an individual level, the driving force of foraging is taxonomic constraint, with variability in food availability and fish assemblage. Herbivores also have an overwhelming preference for turf algae at every site, regardless of the benthic makeup. Across a guild, the total amount of bites a reef is experiencing at one time is organized at a guild level; variations of density, estimated bite rates and selectivity all decreased along an inverse taxonomic gradient. These findings suggest that analyzing foraging behavior and intensity at a guild level is the most beneficial to understanding impact of herbivory on coral reefs.
Smith, J.R.1*, Vogt, S.C.2, Creedon, F.3, Lucas, B.1, Eernisse, D.3
TIDAL ZONE VARIATION IN THE EFFECTS OF THE NON-NATIVE RED ALGA CAULACANTHUS USTULATUS ON NATIVE ROCKY INTERTIDAL COMMUNITIES
1 – California State Polytechnic University, Pomona, 2 – City of Dana Point, 3 – California State University, Fullerton
The turf-forming red alga Caulacanthus ustulatus, a putative introduction from Asia, has become a common component of the rocky intertidal community in southern California since 1999. To evaluate the effects of Caulacanthus on native communities, macrofaunal, meiofaunal, and macroalgal community structure and diversity were compared between patches with (non-native) and without Caulacanthus(native) in the upper intertidal zone at 5 locations. Caulacanthus displaces macroinvertebrates, such as barnacles, limpets, and periwinkles, while facilitating a diverse array of meiofauna and macroalgae. This is likely due to the formation of a novel turf habitat in the upper zone where turfs are uncommon in this region naturally; algal turfs can increase habitat complexity, trap sediment, and maintain moisture during low tide which likely benefits meiofauna and seaweeds by providing food, habitat, or refuge from desiccation stress. Subsequent comparisons of invertebrate and seaweed assemblages were conducted in native and non-native patches at one site in both the upper intertidal zone and in the middle intertidal zone where a native turf zone exists. Despite differences in community composition in the upper zone, no differences were observed in the middle zone, providing support that the novel turf created byCaulacanthus in the upper zone drives community differences.
Smith, L.M.*, Dudgeon, S.R.
GENOTYPIC RESPONSES IN GROWTH AND FORM TO HYPOXIA IN HYDRACTINIA POLYCLINA
California State University Northridge
Sessile, colonial invertebrates adjust to variable environments by sensing environmental signals that trigger adaptive plasticity. Colonies of the hydrozoan, Hydractinia polyclina, grow continuously, lack determinate size and shape, and show a continuum of morphotypes, but experience a wide range of O2conditions in the field. Laboratory studies demonstrate that colonies use oxygen availability (ρO2) to cue morphogenesis, but can colonies in nature discriminate among environmental cues amidst simultaneous variation of potentially conflicting signals? We placed three genotypes factorially in different environments, measured environmental parameters and followed the growth trajectories of colonies. Environments characterized by saturating levels of dissolved oxygen, intermediate flow, and coarse sand, showed a colony-wide increase in stolon branching, polyps and sheet-like tissue, across all genotypes. Environments characterized by reduced levels of dissolved oxygen, low flow, fine sand and silt, showed genotype-specific morphological responses, suggesting a possible genotype x environment interaction. Path analysis showed that colonies in nature respond most strongly to hypoxic signaling in a natural setting, and the strength of response varies among morphotypes. Hydractinia polyclina colonies appear to respond plastically to hypoxia via changes in colony morphology, which may allow these colonies to adapt to the changes in ρO2 that they experience in natural settings.
† Smolenski, J.R.*, Edmunds, P.J.
SPECTRAL DISTRIBUTION OF LIGHT HAS NO EFFECT ON CORAL CALCIFICATION IN RESPONSE TO INCREASED PCO2
California State University, Northridge
Evaluating how corals respond to ocean acidification (OA) under varying conditions is important for conducting ecologically relevant experiments. Light is one source of physical variability, where intensity and spectral distribution vary over space and time with effects that can influence coral performance through multiple pathways. We tested the hypothesis that spectral distribution of light has no effect on the calcification of corals when subjected to high Pco2. Adult fragments of Porites rus from Moorea (French Polynesia), and adults plus recruits of Seriatopora caliendrum from Taiwan, were incubated under similar intensities (~50 µmol photons m-2s-1) of red (peak 645nm, range 580-700nm), green (peak 530nm, range 480-610nm), blue (peak 450nm, range 400–530nm), or white light, and exposed to ambient (~44Pa) and high (~80Pa) Pco2. Calcification was measured as buoyant weight standardized by area following 18d incubations. For both adult species, calcification was unaffected by Pco2 or the interaction between light and Pco2, however, calcification of S. caliendrum was reduced ~32% under red light. For recruits, calcification was reduced ~19% in high Pco2, but was unaffected by light or the interaction between the two. Together, these results suggest that spectral distribution will not affect the calcification response of corals to OA.
† Sogin, E.M.1,2*, Anderson, P.3, Horgen, F.D.4, Williams, P.2, Gates, R.D.1,2
Differential expression of betaines links to performance limits in corals
1 – Hawai‘i Institute of Marine Biology, 2 – University of Hawai‘i at Mānoa, 3 – College of Charleston, 4 – Hawai‘i Pacific University
Corals reefs are ecologically, economically and culturally important to tropical regions worldwide. Unfortunately, anthropogenic stressors are threatening the persistence of reefs into the future. Reef response to stress is non-uniform and the composition of coral reef ecosystems reflects differences in performance among coral species. Understanding molecular mechanisms that drive such variations in response is a central question in coral biology. To contribute to this line of research, and using a non-targeted proton-nuclear magnetic resonance based metabolomics approach, we assessed metabolite profiles in coral species representing key contributors to the structural and habitat integrity of Indo-Pacific reefs. This technique measures a broad range of compound classes, allowing us to capture co-regulatory dynamics in metabolite production. We detected strong differences in metabolite composition of the four coral species studies and found that betaines contributed significantly to this variation. Differential expression of betaines in corals is particularly interesting given their central roles in osmoregulation, antioxidant response and cellular homeostasis, all of which are critical to coral survival. Our research suggests that a more comprehensive understanding of the full diversity of betaines in corals is warranted and will likely contribute new understanding of the cellular mechanisms driving coral ecological performance.
† Spies, B.T.*, Steele, M.A.
THE EFFECTS OF TEMPERATURE, LATITUDE, AND HABITAT PREFERANCE ON LARVAL TRAITS IN TWO NATIVE CALIFORNIA ESTUARINE FISH SPECIES
California State University, Northridge
Variations in the abiotic environment have been found to strongly influence the early life history of marine organisms across large latitudinal gradients. Species such as the arrow goby (Clevelandia ios) and the endangered tidewater goby (Eucyclogobius newberryi) are both found in estuaries along the California coast, however, these two species have a dissimilar preference in habitat type (fully tidal vs. seasonally closed estuaries). This study investigates variations in larval traits of C. ios and E. newberryi in relation to temperature trends found in eighteen estuaries spanning approximately eight degrees of latitude. Newly settled individuals were collected from July-October 2011, along with hourly temperature recordings using iButton and HOBO data loggers, in order to determine how temperature variations affect larval duration, settlement size, and growth rates. Estuaries inhabited by E. newberryi showed high variability in temperature with no significant latitudinal trend. This varied from estuaries inhabited by C. ios, which followed a more traditional latitudinal temperature trend (colder in the north – warmer in the south). Both species experience variations in all life history traits between high and low temperature sites. Fish that experienced colder temperatures, on average, had a longer larval duration, slower growth rates, and were larger at settlement.
Steele, M.A.1*, Adreani, M.S.1, Schroeter, S.C.2, Reed, D.C.2
GROWTH AND TISSUE PRODUCTION OF TEMPERATE REEF FISHES ON ARTIFICIAL VERSUS NATURAL REEFS
1 – California State University Northridge, 2 – University of California Santa Barbara
Artificial reefs are sometimes used to mitigate damage to natural reefs, yet how well these artificial reefs function is still widely debated. One major question yet to be resolved is whether artificial reefs produce fishes at rates equivalent to those on natural reefs. We tested whether rates of growth and total tissue production (somatic + gonadal) of reef fishes on the 176-acre Wheeler J. North artificial reef were comparable to those on two nearby natural reefs. Adults from four of the most common rocky reef fishes in the Southern California Bight (California sheephead, kelp bass, señorita, and blacksmith) were collected during the spawning season in 2009, 2010, 2011, and 2012. Rates of growth and tissue production of each species were generally similar between the two reef types, with rates on the artificial reef being most like those on the natural reef nearest to it. The similar performance of fishes living on the artificial and natural reefs implies that well-designed artificial reefs can mitigate damage to natural reefs by enhancing production of reef fishes.
Stewart, H.L.1*, Copping, I.D.1, Davies, N.1,2, Meyer, C.P.1,3
Insights into the community of associated organisms on a drifting seaweed
1 – Moorea BioCode Project, 2 – University of California at Berkeley, 3 – Smithsonian Institution
Characterization of the biota of systems that are well-constrained geographically offers an unparalleled opportunity to examine the role and importance of vectors moving organisms into and out of the system. The Moorea BioCode Project, an ecosystem-level barcode initiative, has been characterizing the macrobiota on the island and reefs of Moorea in the South Pacific Ocean. Using this database we have begun to address questions about the community composition and spread of organisms associated with a relatively recent seaweed invader in parts of French Polynesia. Detached, floating rafts of the brown alga,Turbinaria ornata drift from island to island on surface currents and are a mechanism of dispersal/invasion/connectivity for this seaweed. Studying and comparing the organisms found inTurbinaria rafts around Moorea and other islands to the BioCode database provides insight into the community inhabiting this floating habitat, arrival pathways for new immigrants, new species behaviour, and the discovery of potentially new species.
Stewart, K.R.1,2*, Dutton, P.H.2
Identifying source populations for sea turtles caught in fisheries
1 – The Ocean Foundation, 2 – Southwest Fisheries Science Center
Sea turtle conservation requires policies to be enacted at local, national and international levels, and thus it is critical to understand threats to these species. To assess impacts of fishing practices on distinct populations of sea turtles, we characterized bycatch turtles using genetic fingerprinting. We then compared each individual’s signature to those of source nesting populations. Here we present two case studies for leatherback turtles (Dermochelys coriacea). First we analyzed samples from Canadian foraging leatherbacks, and using a reference dataset with nine source populations, we assigned each turtle to a nesting beach. We found that of 288 turtles, most assigned to Trinidad, which hosts the largest rookery in the Western Atlantic. In the second case study, we analyzed and assigned 100 bycatch leatherback samples from the Gulf of Mexico (GOM) and 220 samples from the Northeast Distant Waters Fishery Zone (NED). We discovered that turtles in the GOM were primarily from the Costa Rican population, while those turtles caught in the NED were primarily from Trinidad. The fishery in the GOM may represent an area of concern for Costa Rican turtles. We expect that results from these types of analyses will inform management and policy decisions.
Stier, A.S.1*, Hanson, K.M.2, Holbrook, S.J.3, Schmitt, R.J.3, Brooks, A.J.3
PREDATION AND LANDSCAPE CHARACTERISTICS INDEPENDENTLY AFFECT REEF FISH COMMUNITY ORGANIZATION
1 – Northwest Fisheries Science Center, 2 – University of Hawaii, 3 – University of California Santa Barbara
Trophic island biogeography theory predicts that the effect of predators on prey diversity are context-dependent and should shift across heterogeneous landscapes. However, experimental tests of the predicted context dependency in top-down control remain limited. Using a factorial field experiment we quantify the effects of predation and patch characteristics (size, fragmentation) on coral reef fish communities. We found independent effects of predation and patch characteristics on prey communities. Predators reduced prey abundance by 50% and gamma diversity by 45%, with a disproportionately strong effect on rare species relative to common species (60% and 16% reduction, respectively – an oddity effect). Larger patches contained more fishes, but a doubling of patch size led to a modest (36%) increase in prey abundance. Fragmented patches had 50% higher species richness and modified species composition relative to unfragmented patches. Our findings suggest two different pathways (i.e., habitat or predator shifts) by which natural and/or anthropogenic processes can drive variation in fish biodiversity.
AMBIENT FLUID MOTIONS INFLUENCE FEEDING BY THE HYDROMEDUSAE MITROCOMA CELLULARIA ANDAEQUOREA VICTORIA
Oregon Institute of Marine Biology, University of Oregon
Individual species of cnidarian hydromedusae are highly selective in the prey types they consume and are significant predators in coastal ocean ecosystems. However, we lack a detailed, mechanistic understanding of how prey capture interacts with ambient fluid motions. The goal of this study was to measure the influence of realistic turbulence levels on (1) swimming behavior and (2) fluid interactions during feeding by two species of suspension feeding hydromedusae, Mitrocoma cellularia and Aequorea victoria. A laboratory turbulence generator produced realistic levels of turbulence representative of the field (Friday Harbor, WA). Though swimming speeds and accelerations did not change in turbulence, velocity vector maps produced using Particle Image Velocimetry (PIV) showed that feeding currents were eroded by ambient fluid motions in both species. Lowered feeding current velocities near the bell margin and tentacles have the potential to reduce clearance rates. These results demonstrate that feeding current erosion within turbulent flows affect predator-prey interactions by the suspension feeding M. cellularia and A. victoria.
† Swanson, S.A.*
RAPID MORTALITY OF MULTIPLE SPECIES OF SEA URCHINS IN MOOREA, FRENCH POLYNESIA: INITIAL IMPACTS ON THE CORAL REEF COMMUNITY
University of California Santa Barbara
Historically, sea urchins have been noted for remarkable population reductions and explosions that can result in profound impacts on marine communities. The Caribbean mass-mortality event of Diadema antillarum in the 1980’s resulted in a phase shift on some reefs from coral dominance to algal dominance, and this topic has been at the forefront of coral reef ecology for decades. In Moorea, French Polynesia in January of 2013 we observed a multi-species mortality including the echinoids Diadema savignyi,Echinothrix diadema, Echinothrix calamaris, and Echinometra mathaei by an unknown agent. For D. savignyi, in the backreef on the eastern side of the island, the population was reduced by 99% of pre-mortality density and average test size decreased by 75%. The algal turf community did not change significantly in biomass or length at 5 days, 20 days or 6 months following mortality. Additionally, the algal community after 6 months did not show significant changes. The response by the remaining herbivore community is likely imparting resistance for this coral reef to a shift in the benthic community.
† Swezey, D.S.1*, Sanford, E.1, Bean, J.R.1,2, Gaylord, B.1
Roles of plasticity and local adaptation in mediating bryozoan responses to ocean acidification
1 – Bodega Marine Laboratory, University of California at Davis, 2 – Department of Anthropology, University of California at Davis
Recent studies indicate that phenotypic plasticity and local adaptation play important roles in the dynamics of marine populations. However, the way that these phenomena interact to shape responses of marine species to global environmental change is poorly understood. Bryozoans, a group of predominantly calcifying colonial invertebrates, provide a unique study system for investigating the impacts of ocean acidification (OA). Persistent variation in upwelling intensity along the west coast of the United States creates a coastal mosaic of OA, which may induce plastic responses in growth and morphology and/or select for adaptive differences among populations in terms of tolerance for elevated pCO2. Using a newly constructed flow-through CO2 control apparatus, we tested whether two laboratory-reared populations of the bryozoan Celleporella cornuta showed differences in growth, calcification, and reproductive investment in response to simulated future OA conditions. Scanning electron microscopy revealed that elevated pCO2 (1200 µatm) led to partial dissolution of bryozoan skeletons. However, bryozoans grew and persisted under these acidified conditions through morphological plasticity and shifts in energy allocation, with potential indications of local adaptation within the two populations.
† Teesdale, G.N.*, Wolfe, B.W., C.G. Lowe, C.G.
AN ANALYSIS OF SITE FIDELITY, HOME RANGE, AND MIGRATORY BEHAVIOR OF BARRED SAND BASS,PARALABRAX NEBULIFER, ACOUSTICALLY TAGGED WITHIN THE PALOS VERDES SHELF SUPERFUND SITE
California State University Long Beach
Legacy contaminants (DDT, PCBs) still present in sediments at Whites Point, Palos Verdes, California are redistributed through the local food web. As a result, there are “no-consumption” advisories for 21 fish species, including barred sand bass (BSB), along the Palos Verdes shelf. An array of 42 VR2W acoustic receivers moored at fixed positions on the ocean floor covered a 15 km2 site at Whites Point from July 2010-October 2012. Fifty-five BSB were caught within the array, surgically fitted with acoustic transmitters, released, and monitored. Non-spawning season site fidelity (September-May) for individual BSB was 65.8 ± 28.8% days at liberty. Overall home ranges (95% KUDs) were 29,187 ± 5,559 m2 and core home ranges (50% KUDs) were 2,834 ± 392 m2. Ten additional receivers were periodically deployed from vessels at known spawning sites outside the array. Thirty-nine tagged BSB (71%) made seasonal emigrations from PV shelf, during which 24 (44%) were detected at Huntington Flats, 26.1 ± 4.0 km southeast. High site fidelity of mature BSB to small home ranges at Whites Point suggests potential long-term exposure to legacy contaminants. Migration of BSB to spawning aggregations outside the “no-consumption” area extends the human health risk from legacy contaminants beyond Whites Point.
terHorst, C.P.1*, Lau, J.A.2
GENETIC VARIATION IN INVADER RESPONSE TO DIRECT AND INDIRECT SPECIES INTERACTIONS
1 – California State University, Northridge, 2 – Michigan State University
Strong species interactions, such as competition and predation are proposed to increase biotic resistance to invasion. In diverse communities, indirect effects may also generate biotic resistance. However, some invading genotypes may possess traits that make them less susceptible to direct or indirect interactions. Intraspecific variation in traits mediating species interactions may result in variation in the strength of biotic resistance and allow invasion by only some genotypes. We measured the response of many genotypes of an invading plant species (Medicago polymorpha) to direct and indirect effects of insect herbivores and competitors. Insect herbivores increased biotic resistance by reducing invader fitness. Native competitors reduced invasion success, but only in the presence of insects, indicating an indirect ecological effect of the shared insect herbivore. We also found significant genetic variation in the response of invaders to direct and indirect effects. Insects decreased the fitness of Medicago genotypes collected from the native range, but had little effect on Medicago genotypes collected from the invasive range. This variation suggests that biotic resistance may be more effective against some invading genotypes than others. Intraspecific variation in traits related to biotic interactions may contribute to invasion success into a wide variety of novel habitats.
Microbial-Animal Competition in the Cold: Carbon Cycling in a High Antarctic Infaunal Food Web
Oregon State University
The majority of the world’s seafloor is fueled by bursts of seasonal primary production which sustain benthic communities for months to years. For these communities to persist a balance must exist between metazoan consumption of and competition with bacteria. Through a series of mesocosm experiments in which microbial production was manipulated, I tested whether differing food quantity and microbial activity lead to differential uses of microbial biomass by a High Antarctic infaunal community. Independent of treatment and season, there was minimal change in community structure or reproductive state of many species indicating even during the most food limited time of year, the metazoan community was not inhibited by lack of food. In the absence of metazoans, microbial populations proliferated rapidly with the addition of food, however when intact communities were given varying concentrations of food, only the metazoans increased their respiration and uptake while microbial consumption remained constant. This potentially indicates that the animals, either through their activity or top-down forcing, inhibit the microbial populations. Fatty acid and stable isotopic analysis, combined with a biomass-respiration-biomarker model, provide insight into how this interactions is manifested throughout the food web, with the differential role of bacterial biomass during each season resolved.
Torchin, M.E.1*, Miura, O.2, Hechinger, R.F.3
Reversed latitudinal gradients: Parasite species richness and Intensity of interspecific interactions increase with latitude
1 – Smithsonian Tropical Research Institute, 2 – Kochi University, 3 – University of California Santa Barbara
Species richness generally increases from the poles to the equator. This latitudinal gradient in diversity is a robust and general pattern that extends across a broad range of animal and plant taxa. However, the mechanisms structuring this pattern and the scales at which they operate remain a central debate in ecology. We used trematode parasites of two geminate horn snail species (Cerithidea spp.) to begin to decipher mechanisms shaping species richness patterns and to examine the relationship between local and regional processes. The standardized habitat type (host snail) controls for environmental variation and a single widespread regional pool of species (shared trematodes) controls for evolutionary processes providing an ideal test of the mechanisms. We quantified parasitism across 27 degrees of latitude in over 27,000 snails from 40 locations in both the Atlantic and Pacific Oceans, across 5 countries in North and Central America. Counter to conventional patterns of species richness, trematode richness in both snail species is positively correlated with latitude. Further, we compared the intensity of species interactions among trematodes by estimating levels of intraguild predation and found that the intensity of interactions increased from low to high latitudes. We discuss factors that might drive this unusual biogeographical pattern.
COUNTING ON HOWE SOUND: NARROWING THE GAP BETWEEN RESEARCH AND SCIENCE EDUCATION
Vancouver Aquarium Marine Science Centre
Counting on Howe Sound is a unique education program at the Vancouver Aquarium that connects students to research being done in Howe Sound, British Columbia. The program, which we developed over the past year, aims to inform students about the incredible diversity of life in their backyard while engaging them in activities that mimic methods used by marine researchers to collect data. Through pre and post program assessment, we found that students between grades 4‐12 knew very little initially about local marine environments but dramatically improved their knowledge during the program. Over 500 students have already participated and we expect to engage over 1,000 students by June 2014. The Counting on Howe Sound program provides a valuable example of how connecting with a local, science education facility can help communicate research and inspire the public. In this talk, I describe how our program provides a model for raising public awareness of local ecosystems, conservation issues and current research. I will also provide contacts for educational facilities and organizations in Western North America for researchers interested in developing similar programs elsewhere.
† Trebilco, R.1*, Dulvy, N.K.1, Salomon, A.K.2, Stuart-Smith, R.D.3, Thomson, R.J.3, Edgar, G.J.3
GLOBAL SIGNATURES OF SUBSIDIES AND HUMAN ACTIVITIES IN REEF FISH COMMUNITY SIZE STRUCTURE
1 – Earth to Oceans Research Group, Simon Fraser University, 2 – Resource and Environmental Management, Simon Fraser University, 3 – Institute for Marine and Antarctic Studies, University of Tasmania
The prevailing paradigm for understanding the structure of communities has been that species identity determines community assembly and ecosystem function. For near-shore reef ecosystems, this paradigm has struggled to provide and overarching understanding of the processes driving community structure. Using a dataset of visual surveys of reef fish communities of unprecedented size and geographic representation, we undertook a global analysis of the scaling of total biomass with body mass, regardless of species, in reef fish communities (biomass spectra). We found strong and consistent patterns in community size-structure. At the site-scale, biomass spectra slopes are generally flat or slightly negative for tropical reefs (indicating biomass ‘columns’), whereas slopes are generally positive for temperate reefs (indicating inverted biomass pyramids). Slopes are negative at the Ecoregion scale in both temperate and tropical latitudes (indicating bottom-heavy biomass pyramids). These results indicate that size-based processes, above and beyond the contingencies of species identity, play a key role in the transfer and distribution of energy (and biomass) on reefs. Comparing observed scalings with expectations from metabolic theory provides compelling evidence of energetic subsidies at site scales and reveals a global footprint of human impacts on total biomass and size-structure.
† Tuttle, L.J.1*, Sikkel, P.C.2, Hixon, M.A.3
COMPARATIVE PARASITE COMMUNITIES OF INVASIVE RED LIONFISH (PTEROIS VOLITANS) AND NATIVE FISHES ON ATLANTIC CORAL REEFS
1 – Oregon State University, 2 – Arkansas State University, 3 – University of Hawai’i
Biological invasions may result in novel host-parasite interactions: an invader can introduce new parasites to indigenous hosts, and it can acquire parasites from its new range. We compared the macroparasite communities infecting red lionfish, an invasive predator in the tropical western Atlantic and Caribbean, and ecologically similar native fishes at two locations: the Bahamas and the Cayman Islands. Lionfish harbored fewer parasites than native fishes, in terms of both infection prevalence and intensity. All parasites found in lionfish were indigenous to the region. Using multivariate ordinations of hosts in parasite space, we detected significantly different parasite communities infecting each of five host families (lionfish [Scorpaenidae] n = 138, Haemulidae n = 44, Holocentridae n = 31, Lutjanidae n = 15, and Serranidae n = 32). Invasive lionfish and native serranid groupers tended to occupy smaller regions of ordination space than did the other families, perhaps due to the extreme rarity of lionfish or grouper infected by very many parasites. Our data align with other examples of invasive species with depauperate parasite communities, which may explain some of their success if lionfish consequently allocate more energy to growth and reproduction than to immune defenses.
† Tyburczy, W.T.*
SCALING UP IN TIME AND SPACE: EFFECTS OF PREY LEVELS ON WHELK GROWTH, SURVIVAL AND REPRODUCTION, MEASURED ACROSS REGIONS AND YEARS
University of Chicago
Many prominent multi-species models assume that the reproduction and mortality of predators relate directly to their immediate feeding rate and local prey abundance. However, for systems with annually reproducing species, where predation and reproduction occur on very different timescales, the validity of this assumption remains in question. From 2009-2012, I measured growth, survival, and reproduction of the predatory whelk, Nucella ostrina, both in caged manipulations across Oregon and Washington, and in naturally isolated populations in Washington. Whelks in the experiments were exposed to a range of abundances of their barnacle prey. Analysis revealed an effect of barnacle abundance on whelk growth, and a correlation between growth and reproduction, but showed no discernable direct relationship between barnacle abundance and whelk reproduction. The data, combined with a subsequent literature search, also revealed large regional variation N. ostrina survival rates. The results demonstrate the value of conducting research at larger spatial scales, and suggest a need for further empirical investigation of predator-prey systems with annually reproducing species.
† 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 0.14–0.35 units by 2100. Bioerosion of coral reefs is predicted to accelerate due to this unprecedented decline in ocean pH. This present study examines the effects of OA on the boring capacity of Lithophaga laevigataresiding within living massive Porites on the back reef of Moorea, French Polynesia. Abundance ofLithophaga, a common boring bivalve, ranged from 3 to 95 ind/m2 within massive Porites. Size analysis ofLithophaga showed a significant correlation of the borehole opening and valve size, which allowed nondestructive quantification of Lithophaga growth. I conducted a month-long mesocosm experiment where coral cores with and without Lithophaga 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 pCO2 conditions. Results showed no significant difference between treatments yet further investigation of this abundant and active bioeroder under simulated future environmental conditions could provide insight to the poorly understood effects of OA on bioerosion.
Walker, B.J.*, Garza, C.
SCALE DEPENDENCE IN THE RELATIONSHIP BETWEEN TOPOGRAPHIC COMPLEXITY AND INTERTIDAL COMMUNITY STRUCTURE
California State University Monterey Bay
Many factors drive the population distribution of species in intertidal communities. Traditionally, it is expected that physical stressors, like desiccation, dictate upper limits of organisms in the intertidal. Biological stressors, like predation and competition, influence the lower limits for these species. However, small-scale variations in the rocky intertidal may play a significant role in species distribution. Differences in rugosity, relief, and complexity can control habitat suitability for various organisms. In order to isolate the importance of these traits, we scanned four rocky intertidal sites near Monterey, California using a Terrestrial Laser Scanner. This TLS recorded coordinate and elevation data within each site at a resolution of five centimeters. We utilized Geographic Information Systems to translate this data into high resolution, three-dimensional maps. We then performed spatial analyses on these maps to quantitatively assess the relationship between topographic complexity and community structure in the rocky intertidal. The results of our study suggest that not only is there a strong relationship between intertidal topographic complexity and the structure of intertidal communities, but that this relationship exhibits scale dependence. More broadly, our results suggest that the strength of ecological drivers acting upon communities may in part arise from variation in local geological features.
† Ward, P.K.1*, Craig, S.F.2
DEFINING ENVIRONMENTAL CUES OF THE RED ALGAE PRIONITIS SPP. THAT INDUCE LARVAL SETTLEMENT OF THE INVASIVE BRYOZOAN WATERSIPORA SPP.
1 – URM Program, Humboldt State University, 2 – Department of Biological Sciences, Humboldt State University
For sessile marine animals, larval settlement involves crucial choices that determine future success. Marine bryozoans in the genus Watersipora have invaded bays and harbors all around the world due, in part, to larval “niche” traits which exploit international shipping. Our larval settlement studies demonstrated that Watersipora spp. preferentially settle on the red algae Prionitis spp. when given a choice between four different algal species commonly found worldwide. We conducted experiments to identify settlement cues used by these larvae, introducing them to algae in one of three treatments: (1) live (untreated), (2) ethanol-killed and (3) plastic algal mimics. Results showed live algae most strongly induced larval settlement. Chemical cues were tested by introducing larvae to a crude extract ofPrionitis and to seawater in which Prionitis had been immersed: neither induced larval settlement. To test for biological cues, we treated Prionitis with an anti-bacterial cocktail that significantly reduced surface bacteria, which resulted in significantly fewer settled larvae. Our results indicate that the strongest inducer of larval settlement is a biological cue that may be emitted from surface bacteria. Understanding the cues that induce larval settlement is an essential element in determining where and when a successful invasion is likely to occur.
Watson, J.C.1*, Lemieux, G.2, Saville, L.3, Yeomans, A.1, Davey, N.1
THE EFFECTS OF A RETURNING PREDATOR; SEA OTTERS, RED TURBAN SNAILS AND CHANGING PREY DYNAMICS.
1- Vancouver Island University, 2 – Archipelago Marine Research, 3 – Westwind SeaLab
The return of sea otters to the west coast of Vancouver Island, British Columbia is known affect the size and abundance of many invertebrate populations. We examined how red turban snail (Astraea gibberosa) populations differed in areas with and without sea otters. For six years we sampled snails at six sites with and without otters. Snail density did not differ between treatments (areas with or without sea otters) or among years, but mean snail diameter and biomass at sites with sea otters was significantly smaller. We hypothesized that differences in recruitment, size specific survival or growth rates might explain these disparities. Tagging studies, conducted over three years at four sites with and without sea otters indicated that the growth rate in snails <40mm in diameter did not differ between areas. Surprisingly, we recovered ~10X more tagged snails at sites with otters than at sites without otters. Lab experiments and field observations imply that crab predation may be a major mortality source of snails <30mm in areas without sea otters, whereas sea otters appear to prey on snails >35mm. Our results suggest that, off the west coast of Vancouver Island, sea otters have both expected and unexpected effects on the population dynamics of red turban snails.
† Whalen, M.W.*, Aquilino, K.M., Stachowicz, J.J.
Grazer DIVERSITY AND BIOGENIC SUBSTRATE heterogeneity ACCELERATE INTERTIDAL ALGAL succession
University of California Davis, Bodega Marine Laboratory
Spatial heterogeneity in environmental conditions has long been thought to promote coexistence by providing opportunity for niche partitioning. Likewise, environmental heterogeneity may intensify the expression of niche differences in diverse communities and therefore mediate ecosystem processes and state variables. In particular, we were interested in how habitat heterogeneity and grazer community composition interactively determine algal succession. We experimentally tested this idea in the field by manipulating the composition of three gastropod grazer taxa (Lottia digitalis, Lottia scabra, littorine snails) and heterogeneity in barnacle cover on a high intertidal rock wall over the course of one year. Barnacle cover heterogeneity was achieved by removing all or no barnacles from a plot (low heterogeneity), or by removing barnacles from one half of a plot (high heterogeneity). Both grazer diversity and barnacle cover depressed the establishment and accumulation of early successional micro- and macroalgae, but these effects were largely independent. We found, however, that the establishment of perennial macroalgae was simultaneously promoted by herbivore diversity, substrate heterogeneity, and suppression of ephemeral algae. These results imply that effects of substrate heterogeneity on grazing efficiency in this community may only emerge late in succession and may be mediated by early successional species.
Wheeler, S.G.1,2*, Russell, A.D.2, Fehrenbacher, J.S.2
VALIDATING A METHOD OF OTOLITH MICROCHEMISTRY ANALYSIS TO IDENTIFY WATER-MASS ASSOCIATIONS OF LARVAL FISH IN AN UPWELLING REGION
1 – San Diego State University, 2 – University of California, Davis
Otolith microchemisty can be used to determine fish movement patterns and hind-cast geographic location or water mass associations. Interpreting element:calcium ratios in otoliths, however, requires a thorough understanding of natural variation in trace element concentrations and incorporation into otoliths. Our goal in this study is to validate a methodology of otolith microchemistry analysis with the purpose of identifying water mass associations of larval fish in a dynamic upwelling region, using three approaches for method development. First, we characterized seawater chemistry of upwelling-relaxation cycles across multiple years. Second, we experimentally determined the effect of temperature on trace element incorporation into otoliths of recently-settled rockfishes (Sebastes spp.). Finally, we reared juvenile rockfish in a flow-through seawater system across an upwelling-relaxation cycle (~1 month), while simultaneously collecting seawater. This approach allows us to determine the accuracy of otolith chemistry in predicting short-term water mass associations (~5 days). We found significant differences in the chemical signatures of water-mass types with a consistent barium:calcium signature for upwelled seawater. We found that the effect of temperature on elemental signatures varies by element, but not by species. In addition, we report the effectiveness of otolith microchemistry analysis as a tool to identify water mass associations of rockfishes.
White C.F.1*, Anderson P.A.2, Gleiss A.C.3, Skomal G.B.4, Hueter R.E.1, Whitney N.M.1
ASSESSING POST-RELEASE RECOVERY PERIODS IN BLACKTIP SHARKS
1 – Center for Shark Research, Mote Marine Laboratory, 2 – Aquatic Research Department, Mystic Aquarium, 3 – Hopkins Marine Station, 4 – Massachusetts Division of Marine Fisheries
Traditional post-release studies have focused on quantifying mortality of individuals that are landed and released. The few studies focusing on sub-lethal effects of capture stress have often used broad scale measurements of depth to infer changes in behavior. We applied acceleration data loggers to blacktip sharks (Carcharhinus limbatus, N=31, duration= 7-55 hours) in order to assess the lethal and sub-lethal effects of recreational capture stress. Acceleration data loggers provide fine scale (<1Hz) temperature, depth and movement data that can be used to quantify swimming behaviors. We observed three mortalities, all occurred shortly after release (<2hr) producing a post release mortality of 9.5%. However, for individuals that lived, sub-lethal effects were observed up to 20 hours after release. We evaluated 58 metrics of swimming behavior of which 18 showed a significant change in value over time. We used mixed models to fit a logistic relationship between metrics and hour post release to determine the rate of recovery and the time of recovery. Some metrics (e.g. tail beat frequency) were found to display a 50% change between their recovered value and their value immediately after release. Recovery periods were found to range from 7.2 to 14h after release (9.9±1.9h, mean ± SD).
White, C.1*, Costello, C.2
CLOSE THE HIGH SEAS TO FISHING?
1 – Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, 2 – Bren School, UC Santa Barbara
The world’s oceans are governed as a system of >150 sovereign exclusive economic zones (EEZs, ~42% of the ocean) and one large high seas (HS) commons (~58% of ocean) with essentially open access. Many high-valued fish species migrate around these large oceanic regions, and as a consequence of competition across EEZs and a global race-to-fish on the HS, have been over-exploited and return less than their economic potential. We address this global challenge by analyzing the effects of completely closing the high seas (HS) to fishing. This policy both induces cooperation among countries in the exploitation of migratory stocks and provides a refuge sufficiently large to recover and maintain these stocks at levels close to those that would maximize fisheries returns. We find that completely closing the HS to fishing could simultaneously give rise to large gains in fisheries profit (>100%), fisheries yields (>30%), and fish stock conservation (>150%). We also examine the possibility of changing the size of the EEZs themselves. There, we find that some fisheries may benefit from increasing EEZ size, but that a complete closure of the HS still returns larger fishery and conservation outcomes than does a HS open to fishing.
Willette, D.A.1*, Sbrocco, E.J.2, Treml, E.A.3, Steiner, S.C.C.4
AHEAD OF THE SPREAD: AN EARLY WARNING SYSTEM TO PREDICT THE INTRODUCTION AND IMPACT OF INVASIVE SPECIES BEFORE THEY ARRIVE
1 – University of California Los Angeles, 2 – National Evolutionary Synthesis Center, 3 – University of Melbourne, 4 – Institute for Tropical Marine Ecology
Humans have transformed the world’s biotic communities through the intentional and accidental introduction of alien species into new habitats. Survival and uncontrolled spread of alien species categorizes them as invasives. Most research on invasions focuses on responding and managing invasives after their arrival, yet predicting the likelihood and location of invasions would provide unprecedented information to resource managers to plan for invasions before they happen. Here, we used Halophila stipulacea, the world’s first globally invasive marine angiosperm, as our model organism. Our approach was two-fold. First, we asked the question “Where can the seagrass disperse to?” To predict the dispersal pattern of H. stipulacea propagules generated at existing invaded Caribbean sites, we parameterized a spatially-explicit biophysical connectivity model and quantify dispersal potential of propagules to new locations. Next, we asked the question, “Where can the species invade?” To assess this, we identified Caribbean habitat that is potentially suitable for H. stipulacea establishment using ecological niche models. Building ecological niche models from the native Indian Ocean range of the species, we projected these models back onto the Caribbean Sea region to predict locations where the species could establish and generated a map of invasion vulnerability.
Williams, J.P.*, Pondella II, D.J.
THE UNDERWATER 18TH HOLE: ASSESSING THE RESTORATION POTENTIAL OF A BURIED REEF AT BUNKER POINT, PALOS VERDES PENINSULA
Vantuna Research Group, Occidental College
Turbidity, sediment transport and scour along the Palos Verdes Peninsula are associated with: 1) the continuous (1954-present) Portuguese Bend landslide, 2) the landslide of the Trump National Golf Club’s 18th hole in 1999, 3) the recent (2011) landslide at Whites Point, 4) sediment plumes from the nearby Port of Los Angeles, and 5) large storm drains that empty directly into this nearshore environment. These chronic stressors have deleterious impacts to over 100 acres of nearshore rocky reef environment. This study determined the status of the buried reefs in this region and examined this study site’s potential for restoration. Scuba and sonar surveys of the ocean floor from 2009-2013 provided information regarding the extent of reef burial. A small, natural pinnacle reef located inside the study site at a depth of 15m provides an example of how proper reef design can prevent burial by deposited sediment and recreate thriving habitat. Possible locations for restoration were determined by assessing sediment depth as well as the extent of scoured bare rock cover, abiotic cover on rocky reefs, benthic cover of sediment resistant algal and invertebrate species, and available light energy.
Windell, S.W., Garza, C.*
THE VALUE OF HABITAT DIVERSITY IN MARINE RESERVES: SPINY LOBSTERS USE OF THE INTERTIDAL ZONE AT THE SANTA CATALINA ISLAND MPA
California State University Monterey Bay
Marine Protected Areas are a relatively new approach to managing exploited marine species. However, in order for MPAs to be effective, a diversity of habitats that incorporate all necessary ecosystem services for targeted species must be included in their design. The Southern California spiny lobster (Panulirus interruptus) is an exploited species for which MPAs have been designed. Previous work suggests this species forages within the intertidal zone during high tide; however the relative importance of this habitat in the early design of MPAs was not considered. As part of a study to test the efficacy of a longstanding MPA on Catalina Island, California, surveys recording abundance, size, and gender were conducted along transects within and without an MPA at high tide. Intertidal habitat composition was also assessed. These data were paired with a data set beginning before the establishment of the MPA to conduct a BACIPS analysis that quantifies the impact of the MPA and importance of the intertidal zone. We hypothesized that lobster demographics were higher in the MPA as well as higher in the intertidal zone relative to the subtidal. Preliminary results suggest current demographic parameters are higher outside of the reserve due to more suitable intertidal habitat.
† Wirth, C.D.*
GIANT KANGAROO RATS INFLUENCE SPATIAL DISTRIBUTION AND MICROHABITAT USE OF THE COMMON SIDE-BLOTCHED LIZARD
California State University, Northridge
Giant kangaroo rats are ecosystem engineers that modify habitat by building extensive burrowing systems known as precincts, and are associated with greater density and diversity of vertebrates and invertebrate populations, as well as greater plant diversity. These associations can vary across spatial scales (Prugh & Brashares 2011; Davidson & Lightfoot 2007). However, few studies have addressed the functional mechanisms behind these associations and how ecosystem engineering affects the behavior of associated species. My research investigates both landscape and local scale effects of habitat modification by the federally endangered giant kangaroo on the common side-blotched lizard. On the landscape scale, giant kangaroo rats influence the spatial distribution of lizards, while on a local scale, they influence lizard behavior and microhabitat use by providing structural elements for thermoregulation, refuges from predators, and creating higher quality foraging patches by increasing the abundance of arthropod resources. Understanding the functional attributes of the relationship between this keystone ecosystem engineer and associated vertebrate species is essential in conserving the vital role the giant kangaroo rat plays in the ecosystem.
Witting, D.A.1*, Pondella, D.J.2
THE MONTROSE SETTLEMENTS RESTORATION PROGRAMS SUBTIDAL REEF RESTORATION ON PALOS VERDES SHELF
1 – NOAA Restoration Center, 2 – Vantuna Research Group
The Trustees of the Montrose Settlements Restoration Program (MSRP) have identified projects to restore critical Palos Verdes Shelf fish habitat to compensate for interim losses in fish habitat services caused by the presence of DDTs and PCBs in the sediments. One of these projects is to restore impaired subtidal rocky reef habitats that lie directly adjacent to the White Point Wastewater Outfalls. Recent surveys of the nearshore reefs (<30 m) of the peninsula have located nearly 250 acres of buried reefs at Bunker Point with Southern Palm Kelp (Pterygophora californica) growing out of the sediment from where they were still attached to the buried reef. This reef burial was not observed during the extensive surveys of this region in the 1990s, this burial likely occurred in the last decade. The restoration approach is to build artificial reef modules within these restoration sites that will be designed to mimic the high relief reef habitats that have been withstood the chronic impacts of sedimentation and turbidity and remain productive reefs to this day. We will provide a summary of the project with some examples of how this project differs from traditional artificial reef projects.
Wonham, M.J.1,3*, Wyeth, R.C.2,3
QUESTIONS, HYPOTHESES, SURVEYS, EXPERIMENTS: HELPING STUDENTS TEST WHAT THEY MEAN TO TEST
1 – Quest University Canada, 2 – St. Francis Xavier University, 3 – Bamfield Marine Sciences Center
There is nothing like a natural-history field trip to foster student engagement and prompt a steady stream of observations and questions. Honing this raw curiosity into a critical scientific approach to answeringthose questions, however, is a challenge to instructors and students alike. Through inclination and training, scientists routinely generate questions, formulate hypotheses, and design surveys and experiments to test their ideas in the field, lab, or armchair. But what is fun – and second nature – for an instructor often proves opaque and frustrating to a student. What distinguishes a trivial from an important observation? An interesting from a boring question? A testable from an untestable hypothesis? A survey from a manipulative experiment? How well does the study address the original question? The answers are not obvious to the beginning scientist (and occasionally not obvious to the instructor). We present an assignment framework we have refined over ten years of teaching field courses to help students clarify their thinking from field observations through to experimental designs. We illustrate several variations with different pedagogical goals, point out some predictable pitfalls, and qualitatively illustrate the response of students to the assignment both during and after the course.
† Wren, J.L.K.1*, Kobayashi, D.R.2, Toonen, R.J.1
MODELING AND GROUND-TRUTHING THE REEF FISH LARVAL POOL AROUND THE HAWAIIAN ISLANDS
1 – Dept. of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, 2 – NOAA Fisheries, Pacific Islands Fisheries Science Center
Understanding connectivity of marine organisms is imperative to effectively manage and protect marine ecosystems. Most adult reef fish show site fidelity thus dispersal is limited to the mobile larval stage of the fish. In this study we assess larval reef fish distributions in the waters around the Main Hawaiian Islands (MHI), using both in situ and model data. Catches from three years of Cobb midwater trawls around the MHI shows that reef fish larvae are most numerous in offshore waters deeper than 3000 meters and consist largely of pre-settlement Pomocanthids, Acanthurids and Chaetodontids. Larval reef fish abundance shows no relation to total trawl catch or total fish catch. Using a rearward trajectory simulation we identify depth layers and pelagic larval durations (PLD’s) resulting in the greatest settlement probability, and develop a model that predicts larval abundances. By comparing in situ larval shore fish catch with modeled larval abundances we hope to identify physical drivers of connectivity, and highlight geographic areas of high importance to maintaining marine fish populations. This study lays the groundwork for better understanding connectivity in marine fish populations, ultimately leading to the ability of making better-informed management decisions.
† Wrubel, K.R.1,4*, Tissot, B.N.1,2, Bowlby, E.3, Brenkman, K.3, Bright, J.3
FISH-HABITAT ASSOCIATIONS AND THE IMPORTANCE OF DEEP-SEA CORALS IN OLYMPIC COAST NATIONAL MARINE SANCTUARY
1 – Washington State University Vancouver, 2 – Humboldt State University, 3 – Olympic Coast National Marine Sanctuary, 4 – Hershman Marine Policy Fellow, The Nature Conservancy
Declining populations of groundfish have prompted fishery managers to identify important habitats for recovery. Habitats that are important for fish, for spawning, breeding, feeding, or growth to maturity, are classified as essential fish habitat (EFH). However, an EFH Conservation Area off of Washington State was designated with little information on fish distributions and habitat requirements. Consequently, in 2006 and 2008 remotely operated vehicle surveys were conducted to identify fish-habitat associations and the importance of deep-sea corals as fish habitat. Five major habitat and associated species assemblages were identified from multivariate analyses. We parsed out the importance of corals as fish habitat over similar physical substrates and found that low-relief habitats with corals present had higher fish abundance than similar habitats without corals; however fish abundance was significantly higher on boulder habitats without corals than with corals present. Thus, deep-sea corals are likely important components of EFH over lower complexity or mixed substrates, but may not be as important in high-relief complex boulder habitats. This study provides baseline data for current conditions and future comparisons to determine the efficacy of the EFH Conservation Area in rebuilding fish stocks in deep-sea ecosystems.
† Wyse, D.E.1*, McPhee-Shaw, E.E.1, Bellingham, J.G.2, Sudek, S.2
PLANKTON IN MONTEREY BAY: OPTIMIZATION OF OPTICAL SENSOR DATA FROM AUVS WITH APPLICATIONS IN PLANKTON COMMUNITY COMPOSITION
1 – Moss Landing Marine Labs, 2 – Monterey Bay Aquarium Research Institute
Autonomous underwater vehicles (AUVs) equipped with oceanographic sensors demonstrate tremendous capability to describe plankton communities in the marine environment. The vehicles collect data from the surface through the mixed layer for a number of oceanographic parameters. The Monterey Bay Aquarium Research Institute operates the Dorado gulper vehicle, an upper-water-column AUV. TheDorado AUV collects data for 32 size-classes, from 1.25 to 250 μm, using a laser in-situ scattering and transmissometry (LISST-100X) instrument. The objective of this research is to analyze data from multiple sensors on the Dorado AUV to describe plankton community composition in Monterey Bay. Analyzing data from multiple sensors on an AUV can provide a baseline for variability of plankton species in the bay and can further inform sampling methods to target specific classes of plankton. Preliminary results of this study show that specific combinations of LISST-100X size class channels can be combined as surrogates to reconstruct fluorescence data. Other preliminary work on this project includes laboratory sensor calibration using monocultures of phytoplankton. Further research and analysis of laboratory calibration data and in situ data may be useful in establishing organism signature identification for species of interest, particularly harmful algal bloom species.
† Yarid, A.A.*, Edmunds, P.J.
EFFECTS OF INCREASED PCO2 ON THE RESPONSE OF MASSIVE PORITES TO DAMAGE
California State University, Northridge
Ocean acidification (OA) and physical damage are known to affect the physiology of scleractinian corals, but the interactive effects of these stressors have not been investigated. In this study, we tested the hypotheses that coral calcification is unaffected by the combination of physical damage and PCO2 and that the appearance of normal tissue coloration within a damaged area is unaffected by PCO2. We inflicted ~1cm2 wounds 1-2mm deep, similar to those resulting from parrotfish bites, on juvenile colonies (~4cmdiameter) of massive Porities and exposed them to ambient (390µatm) and elevated (970µatm) PCO2at 28°C for 20d. Net calcification was significantly decreased (26% across PCO2 treatments) by damage, and was not significantly affected by PCO2. Though the interaction between damage and PCO2 was not significant, there was a trend for elevated PCO2 to cause a 24% decrease in net calcification among damaged corals, while undamaged corals were unaffected by PCO2. Furthermore, PCO2 did not affect the return of normal tissue coloration within a wound. This study suggests that the response of juvenile massive Porites to small, shallow wounds, such as those inflicted in this study, will be unaffected by the level of OA expected at the end of this century.
† Young, M.A.*
USING SPECIES DISTRIBUTION MODELS TO EVALUATE THE PLACEMENT OF CALIFORNIA MARINE PROTECTED AREAS
University of California, Santa Cruz
With the continued increase in human impacts on the ocean and the realization that the single species approach to management is not adequate, the use of marine protected areas (MPAs) is widely being adopted to supplement traditional fisheries management methods. With the implementation of these spatially explicit policies, there is a need to acquire reliable spatial information on species distributions. California has rapidly established an unprecedented state-wide network of marine protected areas and the development of species distribution models can be utilized to help evaluate the placement and efficacy of these MPAs. In addition to the designation of MPAs, California has also designed and implemented a state-wide mapping project called the California Seafloor Mapping Program, which has provided a high resolution (1-10m) basemap for the entire state waters of California. In this study, I focus on the Central Coast region of California and combined these habitat maps with spatially-explicit ecological observation data to create species distribution models and advance the understanding of ecosystems further than what is achievable through the use of in situ data alone. Using generalized linear models (GLMs) and generalized linear mixed models (GLMMs), I developed species-habitat models for the densities of 7 species (e.g., kelp greenling, gopher rockfish, etc.) of ecologically and economically important demersal fish using SCUBA-based biological observation data collected by one of the MPA monitoring organizations (i.e., PISCO) responsible for monitoring the nearshore ecological communities within kelp forests across the networks of MPAs in California. I related these observations to a variety of seafloor variables derived from the multibeam bathymetry including seafloor complexity, slope, and depth and kelp biomass values derived from LANDSAT imagery. I found that all variables were important in predicting the species distributions; however, seafloor complexity and kelp biomass were consistently the most important predictors. Once the best models were chosen using AIC, these species-habitat associations were extrapolated over the study area to evaluate the distributions of species inside and outside the MPAs. I found the density of several key resource species to be higher inside the MPAs compared to outside. The results of this study help to further our understanding of how the variation in habitat affects the distribution of species and evaluate the effectiveness of the MPAs that were put in place to protect these species.
Yund, P.O.1*, McCartney, M.A.2, Tilburg, C.E.3
CONSTRAINTS ON LARVAL DISPERSAL DETERMINE THE SOUTHERN RANGE BOUNDARY OF THE NORTHERN BLUE MUSSEL, MYTILUS TROSSULUS
1 – The Downeast Institute, 2 – University of North Carolina – Wilmington, 3 – University of New England
The northern blue mussel, Mytilus trossulus, abruptly decreases in abundance south of the Bay of Fundy. The Eastern Maine Coastal Current (EMCC) flows from northeast to southwest along the Maine coast, implying a steady supply of larvae. However, the EMCC diverges from shore where M. trossulusabundance decreases, suggesting that limited mixing between the EMCC and inshore waters may prevent larvae from returning to the coast. Alternatively, larvae or adults may suffer mortality from exposure to higher temperatures inshore of the EMCC. We tested these alternative hypotheses through a combination of field surveys and manipulative experiments. Hydrographic data revealed little to no wind-driven across-shelf mixing in our study region, while the across-shelf distribution of mussel larval was consistent with the hydrography, suggesting that a diverging coastal current can limit across-shelf larval dispersal. Field transplant experiments with juvenile mussels indicated no increase in mortality, while lab experiments suggest higher mortality of M. trossulus larvae only at late season temperatures.
Zahn, L.A.*, Williams, J.P., Claisse, J.C., Williams, C.M., Pondella II, D.J.
ABUNDANCE AND BIOMASS OF IMPORTANT FISHERY SPECIES IN RELATION TO AREAS OF BURIED ROCKY REEF ALONG THE PALOS VERDES PENINSULA
Vantuna Research Group, Occidental College
The Palos Verdes Peninsula is a coastal headland that has been intensively studied with particular emphasis on loss of giant kelp (Macrocystis pyrifera) and rocky reef habitat due to several anthropogenic factors including sedimentation and associated turbidity. In addition to the impacts of fishing, persistent stressors continue to influence these reefs including several landslides over the past 50 years and constant runoff from numerous storm drains causing increased scour and turbidity. Scuba surveys done from 2009-2013 determined the extent of buried rocky reef habitat, as well as species abundance (fish, macroalgae, and invertebrate) and biomass (fish) within a 2.9km2 area offshore of Bunker Point to determine its potential for restoration. Designated reefs around the Peninsula varied greatly in fish and invertebrate species composition as well as abundance. Important fishery species such as kelp bass (Paralabrax clathratus), California sheephead (Semicossyphus pulcher), California spiny lobster (Panulirus interruptus), and red urchin (Strongylocentrotus franciscanus) varied greatly in abundance and biomass among these reefs, which indicates separate stressors of both fishing pressure and decreased habitat through sedimentation. This information illustrates the potential for increased fishery production and habitat enhancement through restoration of these buried reef areas.
Zellmer, A.J.*, Claisse, J.T., Williams, C.M., Pondella II, D.J.
SPATIAL FISHING PRESSURE INDEX FOR ROCKY REEF HABITAT IN THE SOUTHERN CALIFORNIA BIGHT
Understanding the spatial distribution of fishing pressure is crucial for management of fisheries. Here, we utilize spatially referenced records for both commercial and recreational fish taken from 1972-2009 off the southern California coast to generate an index for fishing pressure on rocky reef habitats. For commercial data, we used both the California Department of Fish and Game’s Commercial Fisheries Data to calculate average monthly pounds taken per species per spatial fishing block, and for recreational data, we used the dataset derived from the California Commercial Passenger Fishing Vessel logbooks to calculate average monthly numbers kept per species per block. Fishing pressure totals were calculated both for all reef species of commercial and recreational importance, and individual totals were combined to create a Fishing Pressure Index for all species of interest. Using this information we investigate the spatial and temporal distribution of fishing pressure to understand how these rocky reef habitats have been utilized by fishermen and identify areas of significant fishing pressure.
† Zias, K.J.*
COMMUNITY-LEVEL ARTHROPOD RESPONSE TO RIPARIAN WILDFIRE
1 – Pacific Institute for Restoration Ecology, California State University Channel Islands
Coastal and riparian insect community dynamics are poorly understood, but large episodic events such as El Nino storms are thought to be major drivers of these communities. We took advantage of the lucky happenstance of our having sampled the invertebrate community the week before the massive Springs Fire (May 2013) swept through the Calleguas Creek (Ventura County, CA) region by conducting an immediate post-disturbance sampling that allowed us to document the impact of this fire on the invertebrate community. Interestingly, biomass of arthropods changed little pre- and post-fire but species diversity decrease after the fire. Some groups (e.g. flies) responded dramatically to the burn whereas others changed little. We have seen a very similar pattern with other mobile animals in the wake of the fire, with some vertebrate populations little effected (e.g. coyotes) and others (e.g. rodents) decimated. This differential impact of such disturbance/sensitivity across the community may be a signature of such large-scale apparently “universal” disturbance events.
† Aceves-Bueno, E.*, Gaines, S.D.
HOW FAR ARE TERRITORIAL USE RIGHTS IN FISHERIES FROM AN OPTIMAL SIZE?
Bren School of Environmental Science and management, UCSB
Territorial use rights in fisheries (TURFs) have existed for centuries andmost of them have been established within the boundaries of traditionalfishing grounds (Panayotou, 1982). However, TURFs are gaining attentionas a tool for fisheries’ management in new sites around the world, andtheir creation requires a better understanding of the features that lead totheir success. TURF’s size is an important aspect of their design, affectingtheir efficiency both from an ecological and social standpoint. Previousefforts (White & Costello 2011) have looked at the effects of TURF size onyield, showing that TURFs should be designed tens of kilometers long to generate enough returns. Larger TURFs decrease the spillover of adults and larvae to surrounding areas and thereby create greater incentives for TURF owners to take actions that enhance yields in the future. We compared the optimal size dictated by the model created by White and Costello (2011), with empirical data from TURFs created based on the boundaries of traditional fishing grounds. The difference in size between the empirical TURFs and that predicted from the model is likely due to social constraints and it will have important consequences for the performance of these TURFs.
† Adlof, C.C.*
HOW DOES HARVESTING IMPACT WHITE SAGE (SALVIA APIANA) AS A CULTURAL RESOURCE IN SOUTHERN CALIFORNIA?
California State University Northridge
Biodiversity hotspots, such as the California floristic province, are areas that have both a high concentration of endemic plant species and high amounts of habitat loss. Monitoring endemic species for sources of decline is important in order to maintain as much diversity as possible. One source of decline or extinctions is harvest, if not done sustainably. One plant species, endemic to California, which has experienced recent increases in harvest demands is Salvia apiana (white sage). Salvia apiana is used for ceremonial purposes by local Native American tribes and has been incorporated into other earth/nature-centric religions. Leaves are often gathered from wild populations and there is concern that certain harvest practices may be harmful to the plant. This study examines the effect that different harvest techniques, amount harvested, and season harvest occurs on Salvia apiana.
† Anderson, E.A*, Wendt, D.E., Nakamura, R.
THE EFFECT OF MARINE PROTECTED AREAS ON THE PREDATOR-PREY INTERACTIONS BETWEEN LINGCOD AND ROCKFISHES
Cal Poly Center for Coastal Marine Sciences
Marine Protected Areas (MPAs) are a management tool used to protect fish stocks and buffer against fishing pressure. The California Collaborative Fisheries Research Program has continuously monitored and assessed nearshoregroundfish populations inside MPAs along the central coast since 2007, as well as reference sites adjacent to the respective MPA. The data suggest the abundance and size of lingcod (Ophiodonelongatus), a top fish predator along the central coast of California, has increased inside the Point Buchon State Marine Reserve. However, not all species have responded to the absence of fishing pressure as quickly as lingcod. We expect that the abundance of prey species of lingcod, such as rockfish (Sebastes spp.), might be negatively correlated to lingcod abundance due to trophic interactions. To that end, my proposed project will analyze stomach contents from lingcod inside and outside the Point Buchon MPA to identify possible effects of MPAs on lingcod predation of rockfishes. Stomach contents will be obtained by the gastric lavage technique, and the mass and length of prey items will be quantified. Increased understanding of predator-prey interactions will allow fisheries managers and researchers to make more accurate predictions of how species will respond to an MPA.
† Bachhuber, S.M.*, Sugano, C.S., Kelly, M.W., Rivest, E.B., Hofmann, G.E.
EFFECTS OF ELEVATED pCO2 CONDITIONS ON LARVAL DEVELOPMENT OF RED ABALONE, HALIOTIS RUFESCENS
University of California Santa Barbara
The Red Abalone, Haliotisrufescens, is a commercially and ecologically important species along the Central California Coast. In the past 60 years, abalone populations have been decimated by overfishing and introduced diseases. Declining abundance means that little work has been done on the effects of climate change on these animals. We raised red abalone larvae from a local shellfish farm in high and low pCO2 conditions to evaluate the effects of new stressors on larval growth and development from the egg to pre-settlement phase (approximately 5 days at 17oC). As Haliotisrufescenshas a lecithotrophic larval stage, the effects of stress on development and energy reserves can be observed through biometric and lipid analyses. We found that increased pCO2 increased the number of abnormal larvae after two days of development, and we plan to present further biometric data on larval shell diameter and area. We are currently performing total lipid analysis of the larvae, and plan to conduct specific lipid analysis for carbohydrate, wax ester, phospholipid, triacylglycerol and lipid classes.
† Barnes, C.L.1*, Starr, R.M.1,2, Harvey, J.T.1, Hamilton, S.L.1, Reilly, P.N.3
REPRODUCTIVE BIOLOGY OF CALIFORNIA HALIBUT (PARALICHTHYS CALIFORNICUS): EVIDENCE FROM THE CENTRAL COAST
1 – Moss Landing Marine Laboratories, 2 – California Sea Grant, 3 – California Department of Fish and Wildlife
A clear understanding of the reproductive biology of harvested species is critical for effective resource management. Because the productivity of a population is directly related to its resilience through exploitation, life history traits must be evaluated to ensure fishery sustainability. However, financial and logistical limitations often prevent extensive data collection on maturation, fecundity, spawning frequency, and duration of reproductive seasons. To reduce data deficiencies surrounding California Halibut (Paralichthyscalifornicus)reproduction, 605 fish (344 female, 261 male) ranging from 394 to 1171 mm total length, were collected off of central California in 2012 and 2013. Specimens were measured, weighed, and sexed. Where possible, maturity stages were assigned macroscopically, gonads were weighed to calculate gonadosomatic indices (GSI), and ovarian tissues were preserved for estimates of fecundity. Livers were also weighed to calculate hepatosomatic indices (HSI). Nearly all (i.e., 93.0%) males were actively spawning between May and September, whereas 20.8% of females possessed hydrated oocytes ready for release at time of capture. GSI for both sexes peaked in July, whereas HSI remained relatively constant throughout the season. These data, along with impending fecundity results, will enhance our existing knowledge of California Halibut reproduction while providing essential information for use in future stock assessments.
† Barry, S.N.*, Chiquillo, K.L., Crow, K.D.
HOX EXPRESSION IN PELVIC FIN AND CLASPER DEVELOPMENT OF THE LITTLE SKATE LEUCORAJA ERINACEA
San Francisco State University
Hox genes are considered master regulatory genes that specify organs and appendages during animal development. In early development, expression of Hox genes set up an address system specifying the anteroposterior axis. In vertebrates, limbs develop at later stages and are patterned by the HoxA andHoxD genes during forelimb and hindlimb budding and growth, as well as the specification of digits. In fishes, these same genes are expressed during fin development, yet relatively little is known about development of pelvic fins and differences in Hox expression that may be associated with novel fin modifications. In cartilaginous fishes, the pelvic fins of males are modified to form claspers, intromittent organs used for internal fertilization. Because relatively little is known about Hox expression in pelvic fins, the role that Hox genes play in the evolution and development of genitalia is not well understood in this group. By means of rtPCR and in situ hybridization we are examining the role that the posterior Hox genes play in the development of claspers in the little skate Leucorajaerinacea, including HoxA11,HoxA13, HoxD11, HoxD12 and HoxD13. Further, we are comparing expression of HoxA and HoxD between males and females. Preliminary results suggest that there is no difference between males and females forHoxA11.
† Beach-Mehrotra, M.R.*, Adams, N.L.
COVERING RESPONSE OF PURPLE SEA URCHINS – WHAT’S LIGHT OR PREDATION GOT TO DO WITH IT?
California Polytechnic State University, San Luis Obispo
CA purple sea urchins, Strongylocentrotuspurpuratus, are dominant grazers that live in intertidal and sub-tidal habitats and that covered themselves with shell debris, rocks and drift algae. Multiple physical factors have been shown to contribute to this behavior. For example, some sea urchins respond to and cover themselves in response to ultraviolet radiation (UVR) in a wavelength dependent fashion. Similarly, studies indicate that water temperature, currents and possibly predators may also influence this behavior. One of the most notorious predators of purple sea urchins on the CA coast is the sunflower star (Pycnopodiahelianthoides). We are currently testing whether CA purple sea urchins cover themselves in response to exposure to solar UVR or the presence of P.helianthoides or whether there is an interaction between these factors. Sea urchins are exposed to or protected from UVR while simultaneously in the presence or absences of P. helianthoides.
† Bitter, M.C.*, Kapsenberg, L., Hofmann, G.E.
ASSESING pH VARIABILITY ALONG THE SANTA BARBARA COASTLINE AND ITS EFFECTS ON CALCIFICATION IN COASTAL MARINE COMMUNITIES
University of California, Santa Barbara
Seasonal upwelling events bring nutrient-rich, low-pH waters to the coastal environments of the California Current System (CCS), making the region susceptible to future ocean acidification. Some studies suggest that within the next 30 years the surface waters of the CCS will have summer-long periods of undersaturation with respect to aragonite, with sea floors experiencing yearlong undersaturation. While this pH variability is natural, few studies have examined how an increasingly low pH during upwelling affects coastal marine communities. The aim of this research project is twofold: (1) to quantify the natural variability of pH along the Santa Barbara coastline using SeaFET pH sensors, and (2) examine how this pH variability affects calcification rates of recruitment communities in kelp forest and intertidal zones. The SeaFET pH sensors were co-located with Calcium Accretion Units (PVC recruitment tiles). Community composition and calcification rates on these units will be quantified. This study will provide an insight into how natural pH variability impacts calcification of marine communities and allow for a better understanding as to how California’s coastal communities will respond to possible future ocean change.
† Bogeberg, M.A.1*, Kane, C.N.1, Tissot, B.N.1,2, Walsh, W.J.3
HERBIVOROUS SURGEONFISH USE OF UPPER MESOPHOTIC CORAL REEFS IN WEST HAWAI‘I
1 – Washington State University, Vancouver, 2 – Humboldt State University, 3 – Hawaii Division of Aquatic resources, Kona, Hawai‘i
Surgeonfish (Family Acanthuridae) are both ecologically and economically important species in Hawai‘i. They regulate algae on coral reefs and comprise a majority of fish collected in the aquarium trade in West Hawai‘i. Many surgeonfish make ontogenetic shifts in habitat use on coral reefs. They are reported to utilize deep aggregate coral-rich and sandy rubble habitats at mid to deep depths (15-20 m) as recruits and juveniles and then move into shallow turf-rich boulder habitats as adults. Previous studies, however, have only examined surgeonfish populations from depths of 5-20m. Coral reefs in Hawaii extend to 153m and these deeper reefs could be serving as additional foraging, breeding, or nursery grounds for reef fish. This study aimed to understand the habitat uses of herbivorous surgeonfish at different life stages on a greater depth gradient, extending to the upper mesophotic reef zone (30-40m). Fourteen out of 15 species of surgeonfish were found at all surveyed depths (3-40m). The majority of surgeonfish found at deeper depths (30-40m) were adults. Thus, mesophoitc coral reefs may be serving as additional foraging or breeding grounds for many species of surgeonfish and further studies are needed to investigate the importance of deep reefs for these fish populations.
† Briley, S.K.1*, Ware, R.R.2, Whitcraft, C.R.3, Zacherl, D.C.1
DO OYSTERS HELP EELGRASS PERFORM BETTER IN BED? IMPACT OF A CONSTRUCTED OYSTER BED ONZOSTERA MARINA DENSITY AND LIGHT INTENSITY
1 – California State University Fullerton, 2 – Coastal Resources Management, 3 – California State University Long Beach
Filter feeding bivalves, including oysters, are well-known for their ability to improve water clarity, which has the potential to positively impact seagrasses by increasing light available for growth. However, extremely low population densities of Olympia oyster, Ostrealurida, have limited our understanding of its potential impact on local eelgrass, Zostera marina.An Olympia oyster restoration project built shoreward of an existing eelgrass bed in Alamitos Bay, Long Beach, CA offers a unique opportunity to examine this relationship. We monitored eelgrass shoot density and water column light intensity before and after installation of a constructed oyster bed in an adjacent eelgrass bed and at two nearby reference eelgrass beds. One year after construction, eelgrass near the restored oyster bed shows no significant change in shoot density; but contradictory trends in reference eelgrass beds diminish a clear signal of oyster impact. Oyster impact on light availability is not discernible, as trends for increased light availability in the eelgrass bed near the oyster bed are mirrored in one of the reference eelgrass beds. Continued monitoring and additional measures are necessary to understand the relationship between O. lurida andZ. marina, which is relevant for future restoration of both species.
† Burt, J.M.*, Salomon, A.K.
PATTERNS AND PROCESSES: UNDERSTANDING MULTI-SCALE DYNAMICS IN HIGH LATITUDE KELP FORESTS
Simon Fraser University
Kelp forests are known to collapse rapidly in response to environmental and biological perturbations. The mechanisms maintaining these large-scale phase shifts however, are less well known and demand investigation at multiple spatial scales. In high latitude kelp forests, top-down control of sea urchins by consumers (sea otters and humans) drives transitions between macroalgal-dominated and urchin-dominated states. What is less well known, are the thresholds at which these transitions occur; the internal feedbacks that maintain stable states, the spatial extent to which canopy kelp cover and composition shifts over time; and the implications these changes have on coastal food webs and people. I propose to examine these questions on the Central Coast of British Columbia where sea otters have recently recovered and are rapidly expanding their range. I will use aerial maps and satellite remote sensing data to examine large-scale and long-term changes in canopy kelp cover and composition; subtidal manipulative experiments to empirically examine threshold dynamics; and stable isotope signatures to explore the role of kelp carbon in fueling coastal food webs. Ultimately, this multi-scale investigation of kelp forest phase shifts will help inform marine spatial planning currently underway in the area.
† Carlson, P.M.*, Davis, K., Caselle, J.E.
COUPLING MOVEMENT AND BEHAVIOR: A COMPREHENSIVE STUDY OF A PARROTFISH CHLORURUS MICRORHINOS ON A PRESTINE CENTRAL PACIFIC ATOLL
University of California, Santa Barbara. Department of Ecology, Evolution, and Marine Biology
Coral reef herbivores have been shown to play critical roles in reef resilience by altering the successional trajectories of algal growth. Along with removing algae, herbivores, particularly large parrotfish, exert a distinct benthic effect that exposes new substrate, potentially fostering recruitment of calcifying, reef building organisms. Understanding movement patterns at daily and yearly scales is essential to describe the effect of large parrotfishes on the benthos. To investigate these movement patterns, we have begun a passive acoustic tracking study on Steephead Parrotfish, Chlorurusmicrorhinos, on a pristine Central Pacific coral reef. Coupled with the acoustic tracking, we performed in situ behavioral observations of tagged individuals, measuring bite rate, bite composition, and competitor interactions. We also recorded benthic composition and fish assemblage data at each site. Passive tracking data shows individuals moving 1.0 km away from their consistent daily feeding areas to what appears to be offshore spawning sites, as well as to sleeping areas 200m away from daily feeding grounds. These longer-term movement studies, coupled with behavior observations, reveal the actual time spent feeding and the locally intense grazing patterns of these important herbivores.
† Champieux, T.C.*, Whitcraft, C.R., Zacherl, D.C.
IMPACTS OF A CONSTRUCTED OYSTER BED ON INFAUNAL INVERTEBRATE COMMUNITIES IN JACK DUNSTER MARINE RESERVE
California State University Long Beach
A recent oyster restoration effort in Alamitos Bay CA provides us with an opportunity to analyze the composition of infaunal assemblages under and near constructed oyster beds. Oysters are very important to the health and resilience of estuarine ecosystems because of the many functions they provide to these ecosystems. However, restoration techniques that include bed construction can impact sediment organic matter and benthic invertebrates that also provide trophic support for species of commercial importance.The objective of this study is to assess the impacts of a constructed shell bed on oyster bed-associated sediment and infaunal communities. Preliminary results show there is more organic matter both near and under the oyster bed site as compared to the control site. Overall abundance of invertebrates is reduced only under the oyster bed. There is an altered community structure only under the oyster bed (driven by a reduction in Tubificidae). These results are possibly explained by the shell’s action as a barrier to the mud-water interface. While significant, the impacts of oyster bed construction are spatially restricted to just under the bed. Longer term studies should be conducted to address the effects of the oysters themselves once they settle in greater abundance.
† Clavelle, T., Couture, J.*, Newman, C.,Visalli, M.
EVALUATING THE ECOLOGICAL AND ECONOMIC IMPACTS OF FISHING WASTE PRODUCTS
Bren School of Environmental Science & Management, UCSB
Capture fisheries and aquaculture are essential to global food security and economic growth, especially in small-scale fishing communities. Overexploited and collapsed wild fisheries have been caused by not only increasing global demand for seafood, but by growing non-human consumptive uses as well. These uses include inputs into aquaculture feeds, livestock feeds, pet foods and even agriculture. As these industries continue to amass, reliance on fishmeal and fish oil puts more and more pressure on wild fish stocks, potentially causing significant ecological and social impacts.At the same time, the processing of farmed and wild caught fish is annually generating millions of metric tons of waste. These byproducts can be turned into fish silage for example, a stable fish product that can be used instead of fishmeal as a nutritious feed ingredient in a variety of industries. Silage and other value added products can offer many advantages in areas where resources are limited and there is a need for alternative economic opportunities. The goal of this project is to assess the viability and impact of these value-added products in artisanal fishing communities as a means to increase efficiency of fisheries, provide ecological benefits and generate value for local economies.
† Clements, S.M.*, Kelly, E.L.A., Smith, J.E.
Herbivoresoncoralreefsareinstrumentalinmitigatingthecompetitiveinteractionsbetween reef-buildingcoralsandfleshyalgae;however,notallherbivoresprovidethesameecosystemservices.Surgeonfishesclassifiedas“grazers/detritivores”consume turf‐algaeandtheorganicmattersuspendedintheturfcommunity.ThisstudyaimstoidentifyfunctionaldiversitywithinthefamilyAcanthuridaethroughobservationsofforagingbehaviorinthefieldandanalysisofstomachcontentsforAcanthurusnigrofuscus,A.olivaceus,andCtenochaetusstrigosusat three sites on the leeward side of Maui. Turf communities are the primary spatial competitors to coral at these sites, composing 48-60% of the benthos. Preliminary results from this study support that these three species differ in allocation of grazing efforts over different substrates, including turf, macroalgae, and sand. Analysis of the isotopic signatures of each species at each site will provide an integrated measure of diet over time and will help to determine whether any observed dietary differences are strong enough to influence trophic position. The completion of this project will contribute to a more thorough understanding of fine-scale functional diversity within the grazer/detritivore guild and help to inform future marine policy aimed at coral reef conservation through protection of herbivorous fishes.
† Conroy, L.P.*, Gray, D.A.
MATING ASSESSMENT IN A SONGLESS CAMEL CRICKET
California State University Northridge
Sexual displays convey information about male signalers to the opposite sex. Whether they be visual, acoustic, or chemical, these displays allow females to assess their potential mates. However, in systems in which sexual displays are absent, females must evaluate mates in other ways. Field crickets and other members of Order Orthoptera have served as excellent models for studies of acoustic signaling. However, in the wingless and therefore soundless genus of camel crickets, Pristoceuthophilus, a striking sexual dimorphism exists which might allow for female assessment of male quality. Males in this genus possess “weaponized” hind legs, with large femoral spines and strongly bent tibiae, which have been shown to be used in male-male fighting for access to females. I will present data on how these hind leg traits, in addition to male mass, body size, and condition, predict the likelihood of copulation in the species Pristoceuthophilusarizonae. In addition, I will compare the relative impacts of these traits on copulation probability when females are presented with a single male or two males. These results will shed light on how mates are assessed in a soundless genus in an otherwise songful taxon.
† Davis, K.*, Carlson, P.M., Caselle, J.E.
INDIVIDUAL VARIATION IN SPACE USE PATTERNS OF THE STEEPHEAD PARROTFISH DETERMINED BY ACTIVE TRACKING AT PALMYRA ATOLL
University of California Santa Barbara
Quantifying movement patterns of coral reef herbivores provides valuable information with a variety of applications. With regards to conservation, obtaining spatial and temporal patterns of movement through active tracking can aid managers in the design of protection strategies for these ecologically important species. Herbivorous fishes such as parrotfishes are believed to play an important role in modifying the competitive interactions between corals and algae, facilitating coral recruitment and survivorship. Active tracking of these fishes can illuminate patterns of the spatial and temporal distribution of these impacts. In this study, we tracked individual steephead parrotfish, Chlorurusmicrorhinos, at two sites on the shallow reef terrace at an unfished coral atoll. Our data indicates different movement patterns for C. microrhinos than previously reported. Though core foraging areas for each individual were consistent and small, individuals traveled long distances (100s of meters) from daytime foraging sites to sleeping holes and some individuals traveled long distances (up to a kilometer) offshore to what are possibly spawning sites. Our data suggests that though core feeding areas are similar in size between individuals, overall home range sizes are quite variable and may depend on social dynamics and the mating strategy of the individual.
† Eckdahl, K.A.*, Zacherl, D.C.
BLACK ABALONE (HALIOTIS CRACHERODII) DENSITY ANDHABITAT AVAILABILITY IN SOUTHERN CALIFORNIA
California State University, Fullerton
The black abalone (Haliotiscracherodii) is an endangered species that was once abundant in therocky intertidal zone of southern California until overfishing and Withering Disease drasticallyreduced populations on the mainland and the Channel Islands. Haliotiscracherodiiwas listed asendangered in 2009. The current geographic range of black abalone is from Point Arena, CA toBahia Tortugas, Mexico; however, since the mid 1990s, black abalone have been rare south ofPoint Conception on the California mainland coast. In recent years black abalone populations onthe Channel Islands have experienced recruitment, but the current state of black abalone on thesouthern CA mainland has remained unknown. I am conducting rocky intertidal surveys forblack abalone from Point Conception to San Diego to determine if recruitment is occurring onthe mainland and to measure population density. I am also conducting habitat assessments todocument black abalone habitat availability. Preliminary findings show black abalone are presentbut rare along the southern CA coast; the majority of abalone found may correspond to a singlerecruitment pulse. Good black abalone habitat is present, however, sessile organisms are takingup recruitment space at some sites, potentially transforming good habitat into poor habitat.
† Fitzgerald, M.*, Whitcraft, C., Allen, B.J.
THE RELATIONSHIP BETWEEN BIODIVERSITY AND ECOSYSTEM FUNCTION IN A COASTAL WETLAND
California State University at Long Beach
The gradual loss of 90% of CTZs in California has motivated research aimed at understanding the effects of habitat loss. Biodiversity-ecosystem function (BEF) has historically focused on terrestrial communities however these questions have not been fully explored in wetlands to date. Specifically, I plan to investigate the relationship between plant species diversity and ecosystem functioning in Colorado Lagoon, Long Beach, CA. My research has been designed to answer three specific hypotheses which mainly suggest that overall wetland function will decline with a reduction in species diversity. First, that increasing diversity will result in increased primary productivity and increased resistance to invasion. Second, that observed species-specific variation in individual demographic parameters (e.g., survival) will be correlated with variation in plot-level responses. Finally, that variation in demographic parameters and resulting ecosystem processes among treatments at a given diversity level will be correlated with species-specific functional traits. I selected six native species: Sarcocorniapacifica, Batismaritima, Distichlisspicata, Frankeniasalina, Jaumeacarnosa, and Distichlislittoralis. Preliminary data indicate that there is a strong block effect, but also that the higher diversity treatments have decreased mortality and increased occurrence of non-planted species. With time, I predict that species-specific traits will help explain these differences.
† Fuentes, C.M.1*, Whitcraft, C.2, Zacherl, D.1
OLYMPIA (OSTREA LURIDA) AND JAPANESE (CRASSOSTREA GIGAS) OYSTER
RECRUITMENT ONTO A CONSTRUCTED OYSTER BED IN ALAMITOS BAY, CA
1 – California State University, Fullerton, 2 – California State University, Long Beach
Oyster restoration projects typically seek to increase local oyster density and abundance viaaugmentation of mudflat habitat with hard substrate in hopes of increasing oyster recruitmentrates. We examined the effects of a constructed oyster bed on the settlement rates, recruitment
rates, and adult densities of native Ostrealuridaand non-native Crassostreagigasat Jack
Dunster Marine Reserve in Alamitos Bay, CA. Dead C. gigasshell was used to construct a
2X30m bed. Throughout the next year we periodically monitored shell loss via point-contact
sampling, settlement via deployment of replicate (n=4) ceramic tiles, and recruitment and adult
oyster density via excavation of replicate (n=7) 25cm X 25cm plots randomly placed within the
bed and at an un-augmented control bed. Despite ~72% loss of added shell after one year, therewere higher densities of O. luridasettlers, recruits and adults on the constructed bed relative tothe control, and adult densities were comparable to those of reference populations throughoutAlamitos Bay. Non-native C. gigasalso settled and recruited to the bed but density differenceswere not significant relative to the control. Adding more shell to achieve higher % cover mayresult in a consolidated shell bed with increased O. luridadensity.
† Fulton-Bennett, H.*
SPATIAL TRENDS IN EGREGIA MENZIESII MORPHOLOGY
Moss Landing Marine Laboratories
Point Conception represents a conspicuous distributional break for many marine species in California, yet some taxa previously thought to be limited to areas south of Point Conception have been observed around the Monterey Peninsula, almost 200 miles north of Point Conception. Egregiamenziesii(Turner) Areschoug is an intertidal kelp that ranges from southeast Alaska to Baja California, Mexico and exhibits striking morphological variation between its northern and southern range limits. The northern ‘menziesii’morphology is characterized by a papillated central axis and is thought to dominate habitats north of Point Conception, whereas the southern ‘laevigata’ morphology is characterized by a smooth central axis and is dominant south of Point Conception. This study examined herbarium specimens from throughout the range of E. menziesiito test the validity of this biogeographic pattern and found a wide variety of morphologies north of Point Conception, with ‘laevigata’ showing up in several Central California locations. Importantly, the blade morphology of E. menziesiilacks distinctive latitudinal trends suggesting a high degree of morphological plasticity in Egregia, and provides evidence for a less defined biogeographic boundary at Point Conception.
† Garcia, E.1*, Rouse, G.2
SYNGNATHUS SPECIES WITH VIRTUALLY NO INTERSPECIFIC GENETIC VARIATION: SUGGESTIONS FOR SYNONYMIZING FOUR EASTERN PACIFIC PIPEFISHES
1 – University of California Santa Cruz, 2 – University of California San Diego
Five different Syngnathuspipefishes (Syngnathidae) can be found coexisting in the Pacific coast of California and Baja California compared to only one or two species in the rest of the entire eastern Pacific coast. The source of this relatively high Syngnathusdiversity in Californian waters remains unknown yet there is evidence indicating that this might be a product of our lack of understanding of the taxonomic relationships within this group of fishes. Here, we collected specimens from four of these species,Syngnathusleptorhynchus, Syngnathuscaliforniensis, Syngnathusexilis and Syngnathuseuchrous, in order to obtain 16S and COI mitochondrial DNA data and investigate their genetic relationships. Genetic variation was compared between the analyzed species and phylogenetic trees were generated for both loci using produced and other Syngnathussequences from literature (GenBank). Our genetic analysis failed to recognize specimens as distinct species. Consequently, we recommend synonymizing these four species into a single taxon.
† Gevertz, J.S.*
SELECTIVE SAND GRAIN SIZE USAGE AND RESULTING VARIANCES IN TUBE STRENGTH BY THE SANDCASTLE WORM, PHRAGMATOPOMA CALIFORNICA
Bodega Marine Laboratory, University of California Davis
A wide diversity of adaptations has evolved in rocky intertidal communities to cope with abiotic stresses that impact every organism living in these ecosystems. One approach of particular interest is that of the sandcastle worm, Phragmatopomacalifornica, which finds refuge from wave shock in its masterfully crafted tube of individually selected sand grains and a secreted proteinaceous mucus. In this study I evaluated the selectivity of sand grains used by P. californica individuals in two natural treatments of varying wave stress and sediment size. The strongest tubes were built with a dominant majority of grains less than 0.5 mm in diameter, with a significant decline in strength evident with increased use of larger grains. Stronger tubes were required in conditions of greater wave stress, so smaller grains were used there regardless of local grain availability; in calmer regions, less tube strength was necessary, so more intermediate sized grains were used, resulting in faster tube building. In both circumstances, wave stress influenced the resulting grain selectivity by individual worms. This example of abiotic pressure directly affecting behavior of an intertidal organism demonstrates the vast influence that environmental stresses can have on adaptations and acclimatization of species living in intertidal communities.
† Guerra, A.S.1*, Wood, C.L.1,2, Micheli, F.1
ECOLOGY OF A THREATENED SHOREBIRD IN AN ALTERED HABITAT: BRISTLE-THIGHED CURLEWS (NUMENIUS TAHITIENSIS) ON PALMYRA ATOLL
1 – Hopkins Marine Station of Stanford University, 2 – University of Colorado at Boulder
Palmyra Atoll, USA has remained mostly uninhabited since the construction and abandonment of a US naval base during World War II. However, the effects of Navy modifications made to the land and lagoons have persisted, affecting the physical conditions and benthic habitat quality of some of Palmyra’s lagoon sand flats. Palmyra’s flats provide critical habitat for threatened bristle-thighed curlews (Numeniustahitiensis) and the Atoll hosts one of the largest wintering populations of curlews of any central Pacific island. Thus, Palmyra provides an appropriate setting for studying how land alterations can change the availability of habitat for threatened seabirds. Using camera trapping, observations of focal individuals, and quantification of prey availability and sediment characteristics at sites with varying levels of historical anthropogenic impact, we found that curlew habitat preference was not primarily determined by the degree of Navy impact on lagoon flat habitat, although two of the most impacted sites had the highest curlew abundance. Curlew abundance was most strongly correlated with availability of prey items and sediment composition. These findings provide ecological information on a shorebird species of conservation concern and have implications for land management decision-making at Palmyra Atoll and other curlew wintering grounds.
† Guo, L.W.*, Gilman, S.E.
EFFECTS OF VARIABLE AND CONSTANT ACCLIMATION REGIMES ON THE UPPER THERMAL TOLERANCE OF INTERTIDAL BARNACLE BALANUS GLANDULA
W. M. Keck Science Department
As a unique habitat that encompasses steep environmental gradients, it is important to evaluate threats posed to the intertidal zone by rapid climate change. It is thought that intertidal ectotherms are living close to their physiological limit; therefore slight changes in temperature could result in high levels of mortality. Past studies on intertidal species measured thermal tolerance under constant temperatures, neglecting to consider the impacts of natural variation in field temperatures. We conducted a study on the barnacle, Balanusglandula, to assess if a variable thermal environment would alter thermal tolerance. Barnacles were acclimated in an intertidal mesocosm to either cold (<21◦C), warm (<28.5◦C), or variable (two days cold, two days warm) low-tide temperatures. We measured each barnacle’s critical thermal maximum (CTmax) by increasing air temperature 6◦C/hour and identifying the point at which equilibrium was lost. Barnacles exposed to the warm or variable treatments demonstrated the highest thermal tolerances, suggesting that barnacles are able to shift their thermal maximum. Furthermore, periodic exposure to higher temperatures is sufficient to raise thermal tolerance, reinforcing the need for future studies to incorporate variability in laboratory experiments. These results demonstrate that B. glandula in the field are well-adapted for increasing air temperatures.
† Hancock, J.R.1*, Gaitán-Espitia, J.D.2, Padilla-Gamiño, J.L.1, Hofmann, G.E.1
OCEAN WARMING AND OCEAN ACIDIFICATION EFFECTS ON THE EARLY DEVELOPMENTAL STAGES OF THE GIANT KELP MACROCYSTIS PYRIFERA
1 – University of California Santa Barbara, 2 – Instituto de CienciasAmbientales y Evolutivas, Universidad Austral de Chile
Early life-history stages of marine organisms are highly susceptible to environmental stressors such as those induced by environmental change. Warming ocean temperatures and large-scale climatic events such as El Niño have been shown to affect the recruitment dynamics and growth in natural populations of the giant kelp Macrocystispyrifera. Here, we explored the synergistic effect of ocean acidification and ocean warming on early developmental stages of M. pyrifera. Kelp spores were raised for seven days in a factorial design with temperature (18°C and 13°C) and pCO2 (~370 and ~1800 µatm) as experimental factors. Our results revealed that the combined effects of increased temperature and pCO2 can significantly decrease germination rates, and increase the mortality of kelp spores. Interactive effects of temperature and pCO2 were detected on spore mortality and dormancy. Spore mortality only differed between pCO2 treatments at high temperature. In contrast, spore dormancy was higher in the treatment with low temperature and high pCO2, which is similar to the environmental conditions experienced during upwelling events in southern California. Our results highlight the importance of considering multiple stressors to understand and predict how the early-stages of this important foundation species will be affected by global change.
† Holt, K.*, Neuneker, K., Behrens, M.
DISEASE OF THE PURPLE SEA URCHIN, STRONGYLOCENTROTUS PURPURATUS, ON THE OLYMPIC PENINSULA, WA
Pacific Lutheran University Tacoma, WA
Many species of sea urchins within the genus, Strongylocentrotus, have been documented to suffer from disease. It is likely the causative agent is not the same for all urchin species because the urchins are found in different regions and the disease lesions are not all the same. This study focuses on the two disease pathologies, black ring and red spot, found in the purple sea urchin, Strongylocentrotuspurpuratus, on the Olympic Peninsula of Washington State. The causative agent of this disease is currently unidentified and poorly understood. In this study, repeated cold and warm-season field surveys determined density, size structure and disease prevalence in purple sea urchin on the open coast and in the Strait of Juan de Fuca. Logistic regression analysis shows season and region to be significantly related to disease levels. More disease has been found during the summer and within the Strait of Juan de Fuca, where the average density and mean size are the greatest. However, it is unclear from the data whether density and size are important to disease dynamics. While the relationship between temperature and disease prevalence is limited, urchins are more likely to be recovering from disease in colder seawater temperatures.
† Honka, L.D.1*, Nichol, L.M.2, Salomon, A.K.1
QUANTIFYING SEA OTTER FORAGING DYNAMICS AND DIET DIVERSITY ACROSS A GRADIENT OF OCCUPANCY TIME ON BRITISH COLUMBIA’S CENTRAL COAST
1 – School of Resource and Environmental Management, Simon Fraser University, 2 – Pacific Biological Station, Fisheries and Oceans Canada
Ecological theory suggests that diet diversity increases at high consumer population densities when intraspecific competition is high and prey resource availability is low. As preferred prey items are reduced in abundance by predation, per capita consumption rates are predicted to decline as other prey items become more profitable. We used the recovery of sea otters (Enhydralutris) along British Columbia’s Central Coast to test these theories. In summer 2013, we examined sea otter foraging behaviour across a range of otter densities and occupancy times using direct observations with a 50-80x telescope (Questar). We collected 624 foraging observations from 73 individuals across five study areas varying in occupancy time from 1-25 yrs. Preliminary results suggest an increase in diet breadth across twelve functional prey groups, significantly reduced feeding rates on sea urchins and an increased importance of clams, crabs and mussels with increasing sea otter occupation time. As BC’s recovering sea otter population continues to grow and expand its range, consumption of marine invertebrates by this keystone predator may lead to conflict with First Nations and commercial fisheries. Estimates of the magnitude and functional form of predator-prey interactions can inform the local management of marine resources and facilitate more comprehensive conservation strategies.
† House, P.H.*, Allen, L.G.
PATTERNS IN TROPHIC STRUCTURE OF KELP BED FISHES IN AND OUTSIDEOF AN MPA IN LA JOLLA, CALIFORNIA
California State University Northridge
Fishing pressure has altered community structures of marine habitats worldwide. Multiple studies have shown that overfished ichthyofauna can grow in size, abundance, and reproductive output in Marine Protected Areas (MPAs). How fluctuations in size and abundance of targeted predatory species influence lower trophic levels inside and outside of MPAs in Southern California’s kelp beds has scarcely been assessed. In this study, I tested the hypothesis that an increase in biomass of secondary carnivore fish species inside MPAs will result in a decrease in biomass of herbivores and primary carnivores. A factorial design was used testing the effect of MPA status on trophic structure of fish communities by studying inside the Matlahuayl MPA and outside (Boomer Beach) in a randomized block design. In each area, fish were censused along 12, 50 m transects sampling the benthos and open water and all conspicuous and transient fish were counted, sized (using calibrated lasers and video), and assigned to trophic level. Results show a significant difference in trophic level biomass (p=0.007) in and out of the MPA. Gaining
insight into the trophic role of predatory species is essential to understanding the ecology of Southern California kelp beds and providing information for fisheries management.
† Howard, C.M.*, Eckert, G.L.
VARIABILITY IN SETTLEMENT TIMING AND ABUNDANCE OF JUVENILERED KING CRAB (PARALITHODES CAMCHATICUS)
University of Alaska Fairbanks
Millions of red king crab (Paralithodescamchaticus) larvae are produced each season, yet few survive to recruit to the fishery. King crab stocks in Alaska crashed in the early 80’s and have not recovered, even in the absence of fishing. Understanding the early life history is likely critical to understanding why stocks have not rebounded. Juvenile red king crab larvae settle in nearshore complex habitats where they remain for the first year or two. We conducted red king crab juvenile abundance surveys in intertidal nursery areas from fall through spring 2012-13 and investigated settlement timing and abundance of newly settled individuals by deploying larval collectors subtidally in summer 2013. Collectors were retrieved periodically using SCUBA. Settlement timing was similar to previous years, with settlement occurring in July. The magnitude of settlement in 2013 was similar to 2009, but both were less than 2008. The abundance of recruits that settled in 2012 in the intertidal was lower than in previous years. These studies indicate that settlement timing has remained fairly consistent over time, but larval and recruit abundance varies over time. Understanding variability in larval supply may help explain fluctuations in red king crab abundance in the fishery.
† Ibarra, S.N.*, Eckert, G.L.
IMPACTS OF SEA OTTER RECOLONIZATION ON KELP FOREST COMMUNITIES IN SOUTHEAST ALASKA
University of Alaska Fairbanks, School of Fisheries and Ocean Sciences
Interdisciplinary research is needed to study the effects of top-level predators on process, function, and resilience in marine ecosystems. The reintroduction of sea otters to Southeast Alaska provides an opportunity to study the structure of marine ecosystems along a gradient of occupation of a top-level predator. The expansion of sea otter populations in Southeast Alaska has negatively impacted commercial, sport and subsistence shellfish fisheries, but it is possible that sea otter recolonization may benefit other fisheries because otters promote a diverse kelp-dominated ecosystem. We will investigate these processes by collecting ecological data using SCUBA survey techniques to study the effects of sea otter recolonization (no otters, recently colonized <2 years, established <10 years and established >20 years) on kelp, fish and invertebrates communities throughout Southeast Alaska. Our interdisciplinary study will include local and traditional knowledge through semi-directed interviews on the abundance, distribution, and impacts of sea otter recolonization. Ultimately, our goal is to use input values drawn from resource users and stakeholders as well as analytical information from statistical analyses and conceptual models to estimate the current location, amount, and value of otter-mediated kelp forest ecosystem services and tradeoffs under different management alternatives.
† Ivens-Duran, M.1*, Waltz, G.1, Needles, L.A.1, Nakamura, R.1, Lowham, E.2, Wendt, D.E.1
A SPATIAL ANALYSIS OF CHANGES IN RECREATIONAL FISHING PRESSURE ON THE SOUTH CENTRAL COAST OF CA SUBSEQUENT TO MPA IMPLIMENTATION
1- Center for Coastal Marine Sciences, Cal Poly San Luis Obispo; 2 – Political Science Department, Cal Poly San Luis Obispo
Marine Protected Areas (MPAs) have been implemented to simultaneously promote conservation and rebuild exploited fisheries. While studies demonstrate that MPAs can have significant benefits for overharvested stocks both within reserve boundaries and on reserve edges, few have assessed how MPA placement leads to spatial changes in harvesting effort by the fishing community. Some studies indicate that fishing effort intensifies at the edges of MPAs as fisherman target “spillover” from the protected region. However, few datasets include sufficient pre-implementation data to demonstrate how MPAs change the spatial distribution of fishing effort. Our analysis utilized recreational fisheries data collected by Cal Poly observers aboard commercial passenger fishing vessels operating out of Port San Luis and Morro Bay. These vessels target nearshore fish species, primarily rockfish (Sebastes spp.). We assessed shifts in the spatial distribution of fishing effort from 2003 (four years before south central coast MPA implementation) to 2012 (six years after MPAs were implemented). Using this dataset, we have built a series of maps in ArcGIS that visually depict fine-scale annual fishing pressure. Data through the 2013 season will then be aggregated on a larger scale to facilitate statistical comparisons of effort between years, particularly at the edges of the MPAs.
† Jellison, B.M.*, Gaylord, B.P.
THE EFFECT OF OCEAN ACIDIFICATION ON THE PREDATOR AVOIDANCE BEHAVIOR OF AN INTERTIDAL SNAIL
Bodega Marine Laboratory, University of California Davis
Rising levels of carbon dioxide in the atmosphere are acidifying the world’s oceans, posing a major threat to marine populations and communities. Previous research has emphasized direct effects of exposure of individuals to reduced seawater pH. Ocean acidification can also affect the behavior of organisms and how species interact. Chemoreception enables aquatic animals to perceive their environment and detect potential predators, and abiotic disruption of this process could have important consequences. We investigated the impacts of ocean acidification on trait mediated indirect interactions in a trophic system in Bodega Bay, CA, focusing on the “crawl out” behavior of the intertidal turban snail,Chlorostomafunebralis, induced by predator chemical cues. We exposed turban snails to a factorial treatment of ambient versus acidified seawater and the presence or absence of olfactory cues from the predatory sea star, Pisasterochraceus. We found that the ability of snails to detect predator cues is impaired at the level of ocean acidification predicted to occur broadly in the oceans by the year 2100. These same levels of acidification arise already in rock pools inhabited by turban snails; however, the low pH conditions are confined to discrete time windows associated with low tide. In coming decades, as the fraction of a typical day spent at higher pH levels declines, snails may lose their ability to mount an effective avoidance response, with potential consequences not only for this species but for the trophic web in which they are embedded.
† Johnson, K.M.*, Hofmann, G.E.
OceanacidificationpresentsasignificantthreattomarineinvertebrateslivingwithintheCaliforniaCurrentSystem.Somemarineinvertebratespecies,likethepurpleseaurchin(Strongylocentrotuspurpuratus),exhibitsignsoflocaladaptationalongthislatitudinalgradient.However,thesetraitsdonotfollowaMendelianpatternofinheritance,suggestinganepigeneticroleinadaptationto local conditions. The field of epigenetics represents a wide array of molecular responses that until now have not been widely applied within the context of global change biology. Understanding the role of epigenetics in the cellular response to environmental stress is an emerging field that has the potential to revolutionize our view of phenotypic plasticity and presents itself as a mechanism for organismal response to environmental change. These responses include changes in DNA methylation and histone modifications, which are known to be key players in regulating gene expression by physically interfering with RNA translation. Here I evaluate two techniques that allow researchers to effectively outline changes in global DNA methylation and histone modifications to changes in environmental conditions. Characterizing these epigenetic signatures will enhances our understanding of how trans-generational epigenetic modifications can lead to increased resilience to ocean acidification in subsequent generations.
† Kim, J.-H.*, Kim, K.Y.
OCEAN ACIDIFICATION INDUCED ECOPHYSIOLOGICAL CHANGES OF MARINE MACROPHYTES (MACROALGAE AND EELGRASS): MESOCOSM STUDIES
Chonnam National University
Three mesocosm experiments were conducted to evaluate the influence of ocean acidification on the photosynthesis and growth of marine macrophytes. Mesocosm has a continuous flowing tanks system. CO2saturated seawater was slowly diluted by peristaltic pump into overflowed tanks, which are filled with ambient seawater. First set of mesocosm was tested for five macroalgal species during 2 weeks. Photosynthesis and growth of Sargassumthunbergiiand S. horneri enhanced, but those of Prionitis corneadepressed significantly under high CO2condition. Second and third sets of mesocosm tested for eelgrass(Zostera marina L.) during 3 months over two different seasons (winter and summer), and photosynthesis and growth of eelgrass were enhanced under acidification in both seasons, especially responses were more increased in summer. According to these results, many species of marine macrophytes take an advantage under high CO2 condition in aspects of photosynthesis and growth, and we assume that these positive responses are closely related with optimized carbon acquisition strategies under high CO2 condition.
† Klosinski, J.A.*
QUIT STARING AT MY WRACK, MY EYES ARE UP HERE: BEACH WRACK FROM A KELP FLY’S PERSPECTIVE
Moss Landing Marine Laboratories
Kelp wrack is an important feature of beach ecosystems along temperate coastlines. In California, large forests of the giant kelp Macrocystispyrifera deliver high quantities of kelp wrack to nearby beaches. Utilization of beach wrack by terrestrial organisms can produce very high species abundances, especially for kelp flies in the family Coelopidae that use the kelp for food and habitat. To test the quantitative relationship between beach wrack and fly abundance, beach-cast Macrocystispyrifera was collected along rocky and sandy shores between Davenport, CA and Carmel, CA in late spring to mid autumn 2013. Seasonal changes in the distribution of kelp flies were linked to wrack abundance and its distribution along the coast. More flies were present during the spring and fall compared to summer months. There was also variability between sandy and rocky coasts over the course of the study for both abundance of flies and wrack. From preliminary results, there was no correlation between the wet weight of beach wrack and fly abundance. The coastline supports little productivity and the presence of drift kelp and flies are shown to vary spatially and temporally along the coast with wrack and fly abundances being unrelated during the sampling period.
† Leung, E.*, Allen, L.G.
THE INFLUENCE OF ENVIRONMENTAL VARIATION ON YEAR-CLASS STRENGTH IN WHITE SEABASS (ATRACTOSCION NOBILIS) OF SOUTHERN CALIFORNIA
California State University, Northridge
Studies have shown that species of fish can thrive in warmer sea surface temperatures or decline from a decrease in food availability though lower primary productivity. Otoliths are the calcium carbonate ear stones found in fish. Climate events such as El Niño Southern Oscillation and Pacific Decadal Oscillation can greatly influence the formation of an otolith, where distinct bands in the structure formed during development can represent annual and seasonal variation at a point in time.White seabass (Atractoscionnobilis) was a prominent commercial and recreational fishery species in Southern California during the middle of the last century, but had decline substantially by 1982, largely attributed to overfishing. Recent studies have shown signs that the native population is in recovery and may benefit from El Niño events through increased growth rates. The purpose of my study is to determine if year-class strength in white seabassdiffers dramatically between climate events, using otoliths collected from 1997, 1998, 2000, and 2001 as part of the fisheries independent assessment of juvenile white seabass abundance from 1995 to 2008. The results from this study will ultimately determine the impact of environmental variation on year-class strength of white seabass.
† Linnenbrink, J.M.*, Zacherl, D.C., Eernisse, D.J.
GENETIC POPULATION STRUCTURE OF THE OLYMPIA OYSTER, OSTREA LURIDA, IN SOUTHERN CALIFORNIA
California State University Fullerton
Although oyster restoration projects are ongoing along the west coast of the USA, restoration managers have no information regarding range-wide genetic structure of the Olympia oyster, Ostrealurida, and therefore cannot consider this information when designing restoration projects that allocate time, money, and resources most appropriately. We aim to provide baseline genetic diversity and structure estimates for the historically impacted native Olympia oyster populations in southern California (Mugu Lagoon to Tijuana Estuary) by using non-coding mtDNA and microsatellite markers. We will test for detectable genetic structure among remnant southern California populations and combine our microsatellite data with unpublished data from central California to Washington in order to examine nearly range-wide genetic structure. We hypothesize that southern California populations will have some genetic structure and that genetic similarity will reflect geographic proximity, the pattern for an isolation-by-distance model. We will estimate haplotype or nucleotide diversity, and FST estimates in order to assess within and among-site variation. Baseline data from this study will fill a gap in the literature concerning the population genetics of southern California estuarine species and will allow restoration of Olympia oysters to serve as a model for the restoration of other native estuarine species.
† Madden, J.R.*, Miller, R.J., Yorke, C., Page, H.M.
LIFE HISTORY CHARACTERISTICS OF THE OBLIGATE KELP-DWELLING LIMPET, ACMAEA INSESSA
University of California, Santa Barbara
A species’ life history strategy can be strongly influenced by the disturbance regime it lives in. In marine ecosystems, wave disturbance predictably decreases with depth, and the intertidal zone is most impacted by waves. Previous studies have shown that the kelp Egregiamenziesii, host to the limpet Acmaeainsessa, is vulnerable to wave disturbance in the upper intertidal, where individuals survive <1 year. In response,Acmaeainsessa grows quickly and reproduces early compared to congeners living on rocks in the intertidal. In the subtidal, Egregiais subject to less disturbance, grows larger, and likely survives longer. In this study, we asked whether this greater stability is reflected in the life history strategy of subtidal populations of A. insessa. Egregiamenziesii and A. insessawere collected on subtidal reefs off Santa Barbara, and their size and reproductive state was measured for comparison to intertidal populations. Results thus far suggest that the subtidal population of limpets are larger on average and become sexually mature at a larger size compared to their intertidal conspecifics. This suggests that subtidal populations of Acmaeainsessa are either genetically different than intertidal populations or are phenotypically plastic enough to alter their life history in response to differing levels of wave disturbance.
† Maguire, A.K.1,2*, Rogers-Bennett, L.1,3
The blood sucking “vampire snail”, Evalea tenuisculpta, infects red abalone, Haliotis rufescens, in northern California
1 – California Department of Fish and Wildlife, 2 – Sonoma State University, 3 – University of California Davis
Blood sucking parasitic gastropods in the family pyramidellidae can have significant effects on mollusk fisheries impacting; shell formation, growth rates, mortality, and transmission of disease. We document the presence of pyramidellid snails, Evaleatenuisculpta, on red abalone, Haliotisrufescens, in northern California. Red abalone form the basis for an economically important recreational fishery north of San Francisco and are also important herbivores in subtidal marine communities. We found more than 50% of the red abalone (n=268) examined from eight sites in Sonoma and Mendocino County were infected with these small ectoparasitic snails. Infected red abalone had an average of 9 snails (range 0-57), averaging 4.8mm in length (range 1.0 to 9.2 mm) on their shell. We also document the largest known specimen of its species at 9.2mm. Over three days in the laboratory, parasitic snails (85%) laid at least one egg mass, with larger snails laying more egg masses (containing more eggs) than smaller snails. Egg masses averaged 360 eggs per mass. The high infection rates, parasite loads, and reproductive potential of this snail, combined with little knowledge of the impact of this parasite on red abalone, begs additional investigations into the basic biology and ecology of this host-parasite interaction.
† Marks, L.M.*, Reed, D.C., Holbrook, S.J.
Exploring Factors influencing The Spread of the Invasive Seaweed Sargassum horneri in Southern California
University of California Santa Barbara
Biological invasions are difficult to predict in part because environmental conditions under which introduced species proliferate are not well understood. We are investigating environmental correlates of distribution patterns of the invasive seaweed Sargassumhorneri,which iscurrently spreading rapidly throughout southern California. Introduced in 2003 to Long Beach Harbor from its native Japan, it has since spread to nearshore reefs over 700 km2 across a gradient of environmental conditions throughout the Southern California Bight and into Baja California, Mexico. While the density of S. horneri far exceeds that of native algae in some places, it is also extremely variable. To identify physical and biologicalsources of this variability, we performed quantitative surveys of S. horneri abundance and its environment, including the benthic habitat and biological community. Survey data were analyzed using multivariate techniques to identify habitats, locations and times of year periods that are particularly susceptible to invasion, with the intended goal of informing management efforts to mitigate the effects of invasive species on native ecosystems.
† Marraffini, M.L.*
LIFE BELOW THE DOCKS: HOW COMMUNITY ATTRIBUTES INFLUENCE INVASION SUCCESS
Moss Landing Marine Laboratories
With continued global expansion of humankind and climate change, how will native communities be affected by introduced species? Understanding the relationships between native and introduced species is essential to protect ecosystem functioning and native biodiversity. To examine these relationships, I manipulated initial community structure on artificial hard substrates (tiles) in Monterey Harbor. This experiment varied the diversity, the percent of native species, and percent cover of species within the initial community. Changes in assemblages on tiles were observed through bimonthly photographs. The results showed that all experimental factors influenced the final community composition and structure. Most notably, the percent of native species consistently had a negative relationship with recruitment and invasion success, but species richness had a positive relationship with recruitment. Some of these results do not agree with hypotheses and previous literature but they help demystify aspects of invasion ecology, particularly what allows some areas to be more heavily invaded then others.
† McCollough, R.J.*, Knight, A., Lindholm, J.B.
HABITAT-MEDIATED DISTRIBUTION OF PRAWNS IN SOUTHERN CALIFORNIA
Institute for Applied Marine Ecology, California State University Monterey Bay
Prawns, specifically the spot prawn (Pandalusplatyceros) and ridgeback prawn (Sicyoniaingentis),constitute a valuable commercial fishing industry in Southern California. Despite their economic importance, our understanding of the distribution of prawns has largely come from trawl and trap studies where the fine-scale habitat in which the prawns occur cannot be observed directly. In this study, a remotely operated vehicle (ROV) was used to collect continuous video imagery of demersal communities inside and adjacent to MPAs in Southern California. A total of 42 transects, covering 30.34 km2, were conducted in 2011. From this imagery, we collected geo-referenced habitat data on 1,884 prawns ranging in water depths from 17m to 220m. Prawns were more frequently observed in areas with steep inclines, such as canyon walls and were most abundant at depths ranging from 150m to 200m. These results suggest that depth, slope and substrate may play an important role in their distribution. For instance, depth and canyon complexity could act as a refuge from high fishing pressures in shallower, low-relief areas. The results of this study will be useful for the evaluation of existing MPAs with respect to their efficacy in conserving and managing prawns and other related species.
† McCune, K.S.*, Eernisse, D.J.
YET ANOTHER CRYPTIC PAIR OF WEST COAST LIMPET SPECIES: LOTTIA FENESTRATA AND ITS UNRECOGNIZED NORTHERN COUNTERPART
California State University Fullerton
Lottiafenestrata (Reeve, 1855) has been considered a wide ranging species from southern California to Alaska, with a type locality in San Diego. Although common, it tends to hide from humans (and other predators) on rocks buried in sand. Collectors have sometimes used a variety name, cribraria, which was first introduced as a variety of a different species by Carpenter in 1866. In particular, they have noted the darker interior color of the shell in northern collections of L. fenestrata from as far south as Cayucos, San Luis Obispo Co., CA, but exceptions occur. Combined maximum likelihood analysis (RAxML) of mitochondrial 16S and COI, and nuclear cMDH, have confirmed a clear separation between the two. So far, we have found the northern species only as far south as Santa Cruz, CA and have only found the southern species, L. fenestrata, at multiple localities south of Point Conception. Our ongoing studies are investigating the extent of overlap, if any, along the Central Coast of California.
† Meyers-Cherry, N.L.*, Nakamura, R., Ruttenburg, B., Waltz, G.T., Needles, L.,Wendt, D.E.
ASSESSING MPA EFFECTS ON LIFE HISTORY TRAITS OF GOPHER ROCKFISH (SEBASTES CARNATUS) IN CENTRAL CALIFORNIA
Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo
Gopher rockfish,Sebastescarnatus, comprise 50% of the estimated shallow nearshore rockfish catch in California, yet insufficient data exists concerning the heterogeneity of life history traits between populations. Understanding these characteristics is necessary to determine adaptive management strategies for marine resources. Over time, fishing efforts that target larger individuals can alter size structures of populations, leading to smaller and younger individuals reaching reproductive maturity at a faster rate while reducing overall fecundity (reproductive compensation). Marine Protected Areas (MPAs) established in 2007 may offset reproductive effects. This study addresses the following: 1) Are there differences in growth curves between gopher rockfish in central California MPAs and reference cells? 2) What is the size and age at reproductive maturity for these individuals? 3) Has fishing pressure caused reproductive compensation and reduced reproductive potential and, if so, do MPAs show signs of negating these effects? Length and weight information were recorded from individuals collected during the California Collaborative Fisheries Research Program (CCFRP) 2012-2013 field seasons. In the laboratory, otoliths were aged and gonadal tissues will be processed to conduct histological assessments on timing of maturity. Preliminary growth data has been analyzed using von Bertalanffy growth models, which will address our first question.
† Moriarty, P.E.1*, Essington, T.E.1, Horne, J.K.1, Keister, J.E.2, Parker-Setter, S.L.1, Raatikainen, L.2, Sato, M.1
EFFECTS OF HYPOXIA ON ENERGY FLOW IN PELAGIC FOOD WEBS
1 – School of Aquatic and Fishery Sciences, University of Washington, 2 – School of Oceanography, University of Washington
Fish consumption of zooplankton represents a vital link in marine food webs. This linkage may be sensitive to hypoxia via distributional shifts which occur in response to hypoxia and affect spatio-temporal overlap of fish with zooplankton. Here we present initial findings from a two-year cross-site comparative project in Hood Canal, WA, to describe intensity of feeding of fish on zooplankton and to describe vertical overlap during a year with weak hypoxia. We used acoustics to determine spatial overlap of fish and zooplankton before, during and after the development of hypoxia in four sites in Hood Canal. Stomach content analysis was used to quantify feeding linkages between planktivorous fish and zooplankton. Direct sampling of zooplankton was conducted to describe changes in the zooplankton community over space and time. Initial findings from the 2012 field season, where weak hypoxia developed over the course of the season, indicate that euphausiids are the main prey for Pacific herring and Pacific hake, the dominant zooplanktivorous fish species in Hood Canal. Concurrent changes in spatial overlap over this same time period as hypoxic developed would indicate that the link between zooplankton and planktivorous fish is not affected by the presence of weak hypoxia.
† Murray, J.P.*, Wright, J.R.*, Anderson, S.
MAPPING OF DENDRASTER EXCENTRICUS HABITAT SELECTION
California State University Channel Islands
This research focuses around DendrasterExcentricus, commonly known as Pacific Sand Dollars; investigating their significant importance and how these echinoderms select their habitat. It is in this project where we will conduct a study to test our hypothesis: we will be mapping Dendrasterexcentricuspopulation and looking at their habitat location in relation to depth, density, distribution and positioning. Our preliminary research has shown there is a strong correlation between habitat selection and feeding position. We have selected our sites and will conduct our study at several beaches along the Ventura and Northern Los Angeles coastline. The site locations in which we have chosen for this study all have similar characteristics, yet each have slight variations to show distinctions between our data. Our timeframe for this study will be over the course of several months encompassing seasonal changes and variation in ocean conditions. We will document the trends across our test sites for habitat selection. These results will not only show us the rate of migration for these individuals but enlighten us on the significance of these designated sites.
† Parker, T.A.*, Burnaford, J.L., Zacherl, D.C.
GROWTH AND SURVIVAL OF THE OLYMPIA OYSTER, OSTREA LURIDA, AS A FUNCTION OF TIDAL HEIGHT
California State University Fullerton
Recent surveys of seawalls in southern California bays have uncovered differences in the intertidal distributional patterns of both native (Ostrealurida) and non-native (Crassostreagigas) oysters, where non-natives reach their maximum density higher in the intertidal zone than their native counterparts. These distributional patterns may be explained through differences in settlement, recruitment, and/or growth and survival across species. In a pilot study, we explored the effects of varying tidal heights on the growth and survival of native oysters. Thirty ceramic tiles, each with ten recently settled native oysters, were transplanted onto a seawall in Newport Bay, California at tidal heights ranging from -0.18 m MLLW to +1.30 m MLLW. After 6 weeks, we retrieved 6 tiles (3 each at the extreme highest and lowest tidal heights) and assessed growth and survival rates. No oysters survived above +0.95 m, compared to 35 ± 12.6% survival below +0.01 m. Growth below +0.01 m averaged 0.08 mm/day. Results from an expanded study with both species and more replication could facilitate installment of native oyster restoration beds at tidal heights that maximize survival and growth of natives while minimizing benefits to non-natives.
† Plascencia, I.*, Sanchez, E.*, Anderson, S.
ANALYSIS OF BARN OWLS ON CSU CHANNEL ISLANDS AND THEIRPOTENTIAL TO ASSIST IN CONTROLLING RODENTS IN AN ALTERNATIVEINTEGRATED PEST MANAGEMENT PROGRAM
California State University Channel Islands
We analyzed the barn owl (Tytoabla) diet on the campus of CSU Channel Islands (CSUCI) and in turn explore the potential use of T.ablafor the control of rodents. Owl-based integrated pest management is an alternative to the application of second-generation anticoagulant rodenticide to control small mammal populations. Powerful and efficient rodent control poisons became popular in the 1980s for urban and agricultural use (Hoare & Hare 2006). Recently developed anticoagulant rodenticide sampling methods in wildlife have shown a wide distribution of these poisons upon a range of non-target taxa. Notoedric mange (induced by secondary-anticoagulant exposure) has increasingly plagued southern Californian Bobcats (Lynx rufus), becoming the leading cause of death by 2002. Local mountain lions (Pumas concolor) have also been found with severe cases of notoedric mange, presumably due to secondary-anticoagulant exposure (Klein 2011, Riley 2007). As our CSUCI campus lies within the Santa Monica Mountains National Recreational Area and we are committed to sustainability, we seek to encourage campus use of alternative methods of rodent control. This would minimize the exposure of nearby wildlife to such rodenticides. We analyzed the current diet of T. ablaon and near CSUCI and installed four artificial nest boxes for barn owls.
† Ponomareva, S.I.1*, Williams, B.2, Prokopenko, M.G.1, Sigman, D.3, Wang, X.3, Adkins, J.F.4
EXAMINING POST-DEPOSITIONAL ALTERATIONS IN THE DEEP SEA CORAL, DESMOPHYLLUM DIANTHUS TO ASSESS ITS VIABILITY AS A CLIMATE PROXY
1 – Pomona College, 2 – Keck Science Department, 3 – Princeton University, 4 – California Institute of Technology
To reconstruct past climatic conditions we rely on environmental proxies, especially for times before record-keeping. Here we examine the potential of Desmophyllum dianthus, a deep sea coral, to preserve reliable records of past ocean productivity as nitrogen isotopic composition (δ15N) of the organic nitrogen bound within its aragonitic skeleton. Previous investigation of the modern D. dianthus showed that this nitrogen came directly from the coral’s food source recording the δ15N of algal organic matter exported from the ocean surface, plus some trophic offset. However, prior to using δ15N in D. dianthus as a paleo-proxy we must check for significant skeletal alterations that would prevent it from storing accurate nitrogen isotopic values. The goal of this study was to screen for post-depositional alterations, or diagenesis, in D. dianthus and determine if they are significant enough to invalidate the proxy. The scanning electron microscope (SEM) was used to examine crystal structure and bioerosion in modern and fossil samples. There were no significantly altered crystal structures in the skeleton; however boreholes and burrows were present. In a preliminary comparison of modern and fossil samples, δ15N values did not significantly correlate with boring severity. This research supports D. dianthus use as a climate proxy.
† Potter, E.E.1*, Swanson, J.D.2, Thornber, C.S.1
PLOIDY ANALYSIS OF THE BLOOM FORMING MACROALGAL GENUS ULVA USING FLOW CYTOMETRY IN NARRAGANSETT BAY, RI
1 – University of Rhode Island, 2 – Salve Regina University
Macroalgal blooms occur worldwide, often in shallow areas with low water mixing, and have the potential to cause severe ecological and economic damage. Narragansett Bay, RI is a eutrophic system that experiences summer macroalgal blooms composed mostly of Ulvacompressa and Ulvarigida. All Ulvaspecies have isomorphic, biphasic lifecycles, and the relative contribution of the haploid and diploid life history stages to bloom formation is poorly understood. We first developed flow cytometry protocols to assess the ploidy of individual Ulvathalli. We then assessed the ploidy of U. compressaand U. rigidapopulations from three sites in Narragansett Bay, RI in June, July, and August 2013. During each month we sampled, both haploid gametophytes and diploid sporophytes were present for each species. However, field populations in June and August indicated a clear dominance of gametophytes for both U. compressaand U. rigida. Our results July were less straightforward, with a dominance of gametophytes for U. rigidaand sporophytes for U. compressa. Our data match modeling predictions of gametophyte dominance when the phases are ecologically identical.
† Price, H.L.1*, Gohad, N.V.2, Mount, A.S.2, Wendt, D.E.1
INVESTIGATION OF LARVAL CHEMOSENSORY MECHANISMS IN THE INVASIVE BRYOZOAN B. NERITINA
1 – Cal Poly Center for Coastal Marine Sciences, 2 – Clemson University
Bugulaneritinais a sessile marine bryozoan with a pelagic larval stage. Larvae frequently attach to boat hulls, which facilitates the spread of B. neritina to coastal ecosystems worldwide. This fouling animal not only causes extensive hull damage and significantly increases fuel consumption for marine vessels, but also outcompetes native intertidal organisms in many of the bays and estuaries where it is introduced. Despite the economic and environmental impacts of B. neritina, little is known about larval chemosensory mechanisms in this species. We are investigating the effects of several hormones on larval settlement, and using fluorescence microscopy to elucidate sites of larval chemoreception. Larvae were exposed to varying concentrations of the vertebrate hormone noradrenaline, and preliminary data indicate that the hormone inhibits larval attachment. Future work will include similar assays done with the invertebrate hormone octopamine. Larvae were also stained with the fluorescently labeled alpha-adrenergic receptor ligand BODIPY-Prazosin, and images from both compound and confocal microscopy suggest that B. neritinalarvae possess adrenergic-like receptors, which are concentrated in the apical tuft region. Continuing research will not only provide insight into the chemosensory biology of B. neritina, but may also lead to innovative, non-toxic, anti-fouling strategies.
† Ramirez, M.D.1*, Avens, L.2, Seminoff, J.A.3, Heppell, S.S.1
ANNUAL JUVENILE LOGGERHEAD SEA TURTLE FORAGING ECOLOGY AND HABITAT USE AS INFORMED THROUGH ISOTOPIC ANALYSIS OF BONE TISSUE
1 – Oregon State University, 2 – NOAA Fisheries, Southeast Fisheries Science Center, 3 – NOAA Fisheries, Southwest Fisheries Science Center
Loggerhead sea turtles experience pronounced ontogenetic shifts as they recruit from oceanic to neritic habitats and shift from epipelagic to benthic foraging strategies during their life cycle. The prevailing theory has been that this transition occurs as a distinct, one-way shift based largely on body size. However, recent evidence suggests this shift is reversible. We examined interannual variation in juvenile foraging ecology and habitat use through stable isotope analysis of annual growth rings in loggerhead sea turtle humerus bones. Individual rings were sampled for δ15N and δ13C to reconstruct diet and habitat use histories and were paired with back-calculated straight carapace lengths (SCL) to examine the relationship between foraging strategy and body size. Preliminary analyses indicate a strong positive relationship between isotopic signature and body size (δ15N and δ13C p-values < 0.0001). Additionally, the probability of a turtle exhibiting a benthic foraging strategy increases dramatically with body size (OR = 1.15, p-value < 0.0001), with 50% of turtles predicted to exhibit a benthic foraging strategy at 59 cm SCL. Visual inspection of the stable isotope data suggested that some individuals might migrate back and forth between oceanic and neritic habitats for several years before fully transitioning to a neritic lifestyle.
† Ramsay, E.G.1*, Worden, S.2, Graham, M.H.2
ROCKWEED: LIMPET PARADISE?A STUDY INVESTIGATING LIMPET ABUNDANCE AND ROCKWEED CANOPY COVER
1 – California State University, Monterey Bay, 2 – Moss Landing Marine Laboratories
The study of global climate change and the effects it has on an organism is quite thoroughly understood. However, recent studies have shown that the effect these temperatures may have on the strength of species interactions has not been fully explored. Seaweed canopies, like rockweed, may serve as a refuge to intertidal invertebrates suffering from heat stress and potential desiccation resulting from the rise in temperatures. In this study, the abundance of limpet grazers relative to cover of a high intertidal algal canopy, Pelvetiopsislimitata, was used to evaluate a potential positive species interaction. I predict a decrease in limpet abundance when P. limitata is not present. To test this hypothesis, a randomized block design was used, with barnacle and P. limitata removal and controls at two intertidal sites. Not as predicted, the data shows no significant relationship between canopy cover and limpet abundance, which suggests that P. limitata canopies do not have a significant effect on limpet abundance. However, there was a significant difference found in limpet abundance between the two sites but this could be due to the complexity and rugosity of the substrate types. Future studies will focus on the direct effect of P. limitatacanopies on rock temperatures and humidity, relative to bare rock, which are important stresses in high intertidal systems.
† Rice, C.A.*, Eernisse, D.J., Forsgren, K.L.
MORPHOLOGICAL AND GENETIC IDENTIFICATION OF CALIFORNIA PIPEFISHES (SYNGNATHIDAE)
California State University, Fullerton
California pipefishes are highly diverse and particularly difficult to consistently identify. The widely used Miller and Lea Guide To The Coastal Fishes of California does not include all of the recognized Californian province species. We reexamined the key morphological traits emphasized in pipefish keys seeking to improve the diagnostic separation of pipefish species. Our data indicate that certain features, such as barred markings or a truncated snout, are reliable in separating three recognized species in California; kelp pipefish (Syngnathuscaliforniensis), barred pipefish (S. auliscus), and snubnose pipefish(Cosmocampusarctus). In contrast, a combination of morphological and mitochondrial 16S and COI analyses have so far not supported three currently recognized species as distinct: the bay pipefish (Syngnathusleptorhynchus), and barcheek pipefish (S. exilis), and all could be synonymous with S. californiensis. Future work will further test these conclusions and our goal is to produce a more useful dichotomous key to California pipefishes. We expect to add more pipefish localities and species sequence comparisons and extend what we learn to also better characterize the identification of juveniles. The results from this study will be beneficial to fishery biologists working in the field to more effectively identify pipefishes.
† Rose, J.M.1*, Gouhier, T.2, Chan, F.1, Menge, B.A.1
PLAYING SHELL GAMES: DISTRIBUTIONS OF INTERTIDAL CALCIFIERS AND THEIR MINERALOGIES ALONG THE CALIFORNIA CURRENT LARGE MARINE ECOSYSTEM
1 – Oregon State University, 2 – Northeastern University
One prominent hypothesis regarding biological responses to ocean acidification (OA) is that the pH decline and concomitant changes to carbonate chemistry will affect calcifying flora and fauna more adversely than noncalcifiers. Responses may also vary among calcifiers based on the crystalline form of calcium carbonate (e.g. aragonite, high- or low-magnesium calcite) that is biomineralized by each species. Both hypotheses suggest that there will be ecological winners and losers in marine communities under future OA conditions. To aid in framing investigations of potential OA ecological effects, we have compiled the first analysis of the spatiotemporal distribution of calcifiers and their mineral forms across a Large Marine Ecosystem. Combining a detailed literature review with a 4-year dataset of biodiversity surveys, we identified the primary calcification type for all species encountered at 49 rocky intertidal sites spanning 16 degrees latitude along the California Current Large Marine Ecosystem (CCLME). Our results indicate that sessile species predominantly biomineralize low-magnesium calcite whereas both calcitic forms are common among mobile species. Distribution patterns among major mineral forms are not strongly dependent on upwelling, temperature, or primary productivity at the latitudinal scale, highlighting the utility of enhanced pH monitoring along the CCLME.
† Shomaker, S.M.1*, Paddack, M.J.1,2
CORAL SPECIES & ECOLOGICAL DIVERSITY ON TURNEFFE ATOLL, BELIZE
1 – Santa Barbara City College, 2 – Oceanic Society
Corals on Caribbean reefs have declined drastically in the past 30 years. Turneffe Atoll, Belize is the most biodiverse atoll in the Caribbean and has been shown to have higher coral cover than other areas of the MesoAmerican Barrier Reef, yet the details about coral reef community structure have yet to be evaluated. As part of an ongoing monitoring program, we conducted benthic surveys on forereefs (25-45 ft) of 4 reefs in June of 2013 to examine detailed population structure of corals on reefs near Blackbird Caye, Turneffe Atoll. Total coral cover was near regional levels at all sites, 8-15%, but has held steady over several years. Biodiversity of stony corals was similar among sites (Shannon-Weiner index 2.00-2.08). Coral community structure was evaluated in terms of morphotype, a proxy for reef complexity and ecological function. Mounding corals were most abundant, suggesting that reef structure is being maintained. However, high proportions of non-reef building corals and numerous cases of bleaching and disease were found. This suggests that reefs in this area are not immune to threats felt throughout the Caribbean region and that management actions, such as the implementation of new marine protected areas in this Atoll, are greatly needed.
† Shukla, P.*, Edwards, M.S.
CHARACTERIZING THE PHYSIOLOGICAL EFFECTS OF OCEAN ACIDIFICATION ON JUVENILE PTERYGOPHORA CALIFORNICA AND LAMINARIA FARLOWII
San Diego State University, Coastal and Marine Institute and Laboratory
Climate change driven by human activities has led to dramatic increases in atmospheric CO2concentrations, altering global temperatures and oceanic chemistry. Currently at 400 ppm, atmospheric CO2 is predicted to reach 1000 ppm by the year 2100 and concomitantly dissolved CO2 will decrease seawater pH. The physiological consequences of these rapid changes have been explored in terrestrial forests and coral reefs, but remain understudied in kelp forests. In addition to providing complex habitat for commercially important organisms, kelp forests are one of the most productive marine ecosystems. Through photosynthesis and respiration, they play a key role in the coastal carbon system. Specifically, their ability to utilize both CO2 and HCO3–during photosynthesis affects the local distribution of dissolved inorganic carbon (DIC). DIC proportions are expected to shift with elevated CO2 concentrations, but it is unclear if CO2 and HCO3– uptake by kelps will differ under climate change conditions. In this study, juvenile sporophytes of Laminariafarlowiiand Pterygophoracalifornica were cultured in laboratory mesocosms for 16 days in current conditions (400 ppm CO2) and elevated conditions (1000 ppm CO2). Growth rates, DIC utilization, and saturation irradiances were measured after two weeks and will be presented.
† Sievers, K.T.1*, Barr, R.J.1, Maloney, J.M.2, Anderson, T.W.1, Driscoll, N.W.2
MULTIPLE HABITAT STRUCTURAL COMPONENTS AND THE DISTRIBUTION OF ROCKY REEF FISHES AT LARGE SPATIAL SCALES
1 – San Diego State University, 2 – Scripps Institution of Oceanography
Habitat structure influences the distribution of organisms at small and large spatial scales. Marine coastal environments are often characterized by patches of rocky bottom habitat interspersed with areas of relatively featureless sand. The distribution, abundance, and body size of temperate rocky reef fishes within and among these patches are likely influenced by multiple habitat components including: spatial configuration of reefs, macroalgae density, and benthic rugosity. In this study, subtidal surveys are paired with high resolution bathymetry to explain the distribution of fishes across 100 km of Southern California coastline. Multibeam sonar allows for extremely high resolution mapping of physical habitat and delineating area and geometry of reefs. We will evaluate how macroalgae, benthic rugosity, and reef configuration influence the density, abundance, and size structure of reef fishes. Combining high resolution data on the physical structure of rocky habitat with subtidal surveys of biogenic habitat and fish assemblages will determine the important drivers of fish population structures at a scale meaningful for effective management.
† Smith, J.M.*, McCune, K.S., Eernisse, D.J.
WHEN IS A KEYHOLE LIMPET A GIANT?: A RAPID AND INEXPENSIVE ASSAY TO VERIFY MEGATHURA CRENULATA BLOOD PRODUCTS IN MEDICINE
California State University Fullerton
In southern California a blood protein known as Keyhole Limpet Hemocyanin (or KLH) is non-lethally extracted from aquaculture-raised giant keyhole limpets, Megathuracrenulata. KLH is becoming a commercially and pharmaceutically important product, which is used as a delivery agent for stimulating auto-immune response or fighting cancer. It is vital for both consumer and producer to verify authenticity and detect counterfeits. We used a multiple sequence alignment across Fissurellidae to design a combination of 16S ribosomal DNA primers that can be used for species specific PCR-based verification, without sequencing. A combination of two universal primers and two giant keyhole limpet specific primers were found to amplify with two alternative patterns, a double band of short amplified fragments associated only with Megathuracrenulata or else a longer single 16S product for most other gastropods, including other Fissurellidae. This was tested on genomic DNA extracted from both tissue and blood and was found effective for DNA prepared from a range of blood concentrations.
† Smith, J.G.1*, Waltz, G.T.2, Needles, L.A.2, Wendt, D.E.2
THE RELATIONSHIP OF ENVIRONMENTAL CONDITIONS ON THE CATCH RATES OF NEARSHORE FISH SPECIES ALONG THE CENTRAL CALIFORNIA COAST
1 – California State University, Monterey Bay, 2 – Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo
The California Collaborative Fisheries Research Program (CCFRP) has been monitoring Marine Protected Areas (MPAs) and adjacent non-protected areas using standardized hook-andline fishing methods since 2007. One metric calculated from CCFRP data and used to assess fish stocks is the catch per unit effort (CPUE). CPUE is a standardized measure of a fisheries stock, and the value is based in part on the fish density or abundance. Perception in the fishing community is that certain environmental conditions also affect CPUE. However, the science demonstrating these relationships for rockfish has been relatively unexplored. Using a multiple linear regression analysis, we examined the effect of several environmental factors on the CPUE of rockfish in Monterey and San Luis Obispo Counties. Swell height and wind speed were found to have a significant negative relationship with CPUE. Sampling month and fishing location were also significantly related to CPUE. To complement this analysis, we created an angler survey to assess the perception of the fishing community between environmental conditions. The multiple regression and complementary angler survey serve the dual purpose of elucidating contributing factors to the variability of CPUE calculations and examining the validity of angler perceptions regarding the effect of two environmental conditions on catch rates.
† Srednick, G.S.*, Garza, C.D.
A LATITUDINAL EXAMINATION OF METACARCINUS MAGISTER MEGALOPAE AND SETTLER RECRUITMENT THROUGH TIME SERIES ANALYSIS ON THE CENTRAL CALIFORNIA COAST
Marine Landscape Ecology Lab, California State University, Monterey Bay
The mechanisms that drive population variability in marine systems is a prime research area for ecologists. In particular understanding the impact variation in larval recruitment has on marine populations can enhance our basic understanding of how populations are regulated and in turn can be used to inform the management of ecologically important marine species. In this study a time series of megalopae and settler recruitment was conducted at Moss Landing, California beginning in early March 2013, to assess abundance of larval Metacarcinus magister to inform fishery management. Light traps were used to collect crab megalopae and settlers daily within the Moss Landing harbor to examine expected fluctuations in recruitment numbers. Tidal, wind, and temperature data were collected and used to test for possible correlations with megalopae and settler abundance. Fluctuations in megalopae-settler ratio were observed from early March through June as consistent with M. magister larval cycle. Similar studies were conducted in three other California sites: Bodega Bay, Fort Bragg, and Eureka. Based on a time series analysis at different latitudinal sites, we predict that megalopae-settler landings at the four sites will exhibit spatial dependence in their relationship to local environmental processes. Results will be used by the California Department of Fish and Wildlife to assess latitudinal variations in recruitment and to inform M. magister fishery management for the 2013/14 season.
† Stein, L.S.*, Nakamura, R.
THE FREQUENCY OF ROCKFISH EXPERIENCING BAROTRAUMA IN CENTRAL CALIFORNIA
Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo
Approximately 60% of all fish caught globally in recreational fisheries are returned to sea or discarded annually. Rockfish (Scorpaenidae: Sebastes spp.) are an important coastal fish assemblage that consists mainly of demersal species. When anglers bring in rockfish from about 60 feet or deeper, the fish experience barotrauma. This is due to rapid expansion of the swim bladder as the fish are brought to surface. Buoyant barotruamaed fish released or discarded at the ocean’s surface are generally unable to return to the bottom and are commonly taken by predators such as pelicans and pinnipeds. However, not all species of rockfish may be equally vulnerable or respond uniformly to barotrauma. The data shown in my study appear to confirm this.
† Succow, M.S.1*, Lamb, C.A.1, Mackie, J.A.2, Craig, S.F.1
COMPETITIVE INTERACTIONS BETWEEN CRYPTIC SPECIES – AN INVESTGATION OF THE WATERSIPORA SUBTORQUATA (BRYOZOA) COMPLEX
1 – Humboldt State University, 2 – San Jose State University
An invasive bryozoan, Watersipora ‘subtorquata,’ (a species complex) has become common in many marine communities through introductions of different species within the genus. COI genetic variants common in California are referred to as clades A, B and an unnamed species “n.sp.” While the distributions of these clades differ along the California coast, in several locations all three occur- often with one clade dominant in biomass. Using all three clades of Watersipora, we studied the competitive interactions of colonies when grown into contact.Following collection from multiple field sites, colonies were induced to release larvae, which were settled onto plastic and clipped onto glass slides to pair competitors. Photographs of colonies were analyzed to examine growth rates (pre and post-contact) and whether the (1) angle of contact, (2) length of interaction zone, (3) area of whole/living colony, (4) number of all/ living zooids, and (5) perimeter length of whole/living colony predicted the outcome. Results showed varied interactions, including overgrowth of “n. sp.” onto clades A/B, re-directed growth upwards upon contact of “n. sp.” with A/B, as well as fusion between colonies of “n. sp.” These results may reveal why particular sites are dominated by one clade despite multiple introductions of all three.
† Takata, M.K.1, Jorgensen, S.J.2, Groth, L.3, Kanive, P.4, Chapple, T.K.5, Anderson, S.6, Block, B.A.5
ARE WE RELATED: THE CONNECTIVITY OF CARCHARODON CARCHARIAS IN THE NORTHEASTERN PACIFIC
1 – California State University, Monterey Bay, 2 – Monterey Bay Aquarium, 3 – Great White Adventures, 4 – Montana State University, 5 – Stanford University, 6 – Point Reyes National Seashore
White sharks (Carcharodoncarcharias) comprise a single genetically distinct population in the Northeastern Pacific (NEP). Within the NEP there is limited knowledge about the connectivity between Central California and the Guadalupe Island (Mexico) groups of adult white sharks. Previous studies have documented only a single adult moving between Central California and Guadalupe Island. However, this study relied on acoustic or satellite tags which have a limited effective life span of 2 to 4 years and may underestimate the degree of connectivity. Past studies have validated dorsal fin morphology as an effective identification method for upwards of 26 years. Using an 11 year historic video data set ranging from 2000 to 2011 we are visually identifying individuals to determine connectivity over extended time periods Our preliminary results point to a more connected population within the NEP than previously thought. A higher level of exchange between these groups would need to be accounted for in population estimates at each site, and would mean that white shark management would need to involve a joint international effort between the United States and Mexico.
† Tobosa, L.R.1*, Hurst, T.P.2
EFFECTS OF OCEAN ACIDIFICATION ON GROWTH RATES OF LARVAL NORTHERN ROCK SOLE (LEPIDOPSETTA POLYXYSTRA)
1 – Marine Landscape Ecology Lab, California State University, Monterey Bay, 2 – Fisheries Behavioral Ecology Program, Alaska Fisheries Science Center
Ocean acidification is occurring as a result of dissolution of anthropogenically-generated atmospheric CO2into the world’s ocean. Oceanic pH has decreased 0.10 – 0.15 units within the last 50 years, and is expected to decrease an additional 0.14 – 0.35 units by the year 2100. We examined the responses of northern rock sole (Lepidopsettapolyxystra), a commercially important flatfish species found in the Bering Sea and Gulf of Alaska to ocean acidification. Larvae were reared at four pH levels, from 8.05 to 7.30, at 8˚C in three experimental trials. Larvae were sampled at weekly intervals for 4 weeks for morphometric measurements of standard length, myotome height, and eye diameter. There were no significant differences among pH treatments on growth rate or condition factor in northern rock sole larvae. The lack of a significant negative effect of elevated CO2 suggests that they may be resilient to the physiological effects of ocean acidification. However, they might be sensitive to other ocean acidification effects on sensory biology, behavioral responses, or food web alteration.
† Tronske, N.B.*, Burnaford, J.L., Forsgren, K., Zacherl, D.C.
DENSITIES AND HABITAT DISTRIBUTIONS OF TWO OYSTER SPECIES IN SOUTHERN CALIFORNIA AND THE REPRODUCTIVE POTENTIAL OF C. GIGAS
California State University, Fullerton
Man-made substrata often harbor high ratios of non-native to native species. Alamitos Bay is highly urbanized with little natural substrata, which could affect distributional patterns of California’s only native oyster, Ostrealurida, and the non-native oyster, Crassostreagigas, especially when compared to Newport Bay, which has more natural substrata. We quantified percent cover and oyster densities in quadrats (0.25m2; n=20-30 per site) to explore whether species distributions differed on natural versus human-introduced habitat types. O. luridadensitywas 5.8 times greater in Newport Bay than Alamitos Bay and the native oyster was more abundant than C. gigas in both bays. The proportion of non-native to total oysters was not different between natural and human-made habitats in Alamitos Bay but was higher on human-introduced habitats in Newport Bay. To assess the possibility that feral C. gigas may be reproductive in southern California, gonadal tissue was collected from adults for histological examination. All individuals contained primary and secondary spermatocytes and/or oocytes. Histology will be performed monthly to monitor development and maturation. Knowledge of distributions, densities, and reproductive potential of oysters in southern California are useful tools for native oyster conservation efforts and can provide a benchmark for future studies.
† Turner, K.R.1,2*, Smith, D.M.1,2, Brant, M.A.1,3, Sebens, K.P.1,2
FACILITATION OF ROCKFISH BY OCTOPUS IN THE SALISH SEA
1 – Friday Harbor Laboratories, 2 – University of Washington, 3 – University of Washington Tacoma
Octopuses are generalist predators that feed by biting or tearing into prey, or by boring a small hole through the prey’s exoskeleton and injecting a cocktail of paralytic and digestive enzymes. These modes of feeding lead to leakage of prey tissues into the surrounding waters. Scavengers may be attracted to these clouds of prey tissue, or the remnant shells left by the octopuses in midden piles. Because octopuses tend to bring prey back to permanent den sites to feed, these dens could become relatively constant attraction points for scavengers. In the San Juan Archipelago, we are monitoring giant Pacific octopus (Enteroctopusdofleini) dens for evidence of increased scavenger activity. Shrimp, especiallyPandalusdanae, are likely scavengers, and are also the preferred prey of copper rockfish (Sebastescaurinus). We are using time-lapse photography to quantify rockfish and other demersal predatory fish visitation rates and durations at occupied and unoccupied octopus dens. If octopuses facilitate rockfish by attracting prey species, ecosystem-based management of rockfish in the Salish Sea could include the protection of octopuses, such as with the recently adopted octopus protection sites in Puget Sound.
† Voigt, E.P., Hovel, K.A
The effect of structural complexity on interaction strength of key consumers in a temperate seagrass ecosystem
Department of Biology and Coastal & Marine Institute, San Diego State University
Seagrass habitats are an integral part of coastal marine ecosystems, promoting increased species diversity and high primary productivity. Both top-down (grazing, predation) and bottom-up (nutrient loading) processes may regulate seagrass growth, abundance, and structural complexity. Epiphytic algae, which grow on seagrass blades, are capable of outcompeting and effectively smothering seagrasses when nutrient loads are high. However, mesograzers (e.g. gammarid amphipods, isopods, shrimp, and snails) consume epiphytic algae, promoting seagrass growth. In turn, dense, structurally complex seagrass may house diverse and abundant mesograzer assemblages, potentially resulting in a positive feedback loop that maintains dense seagrass patches. In light of this, we assessed how structural complexity (shoot density) affects the functional roles of mesograzers in terms of their affect on epiphytic algae abundance and seagrass productivity. We transplanted eelgrass (Zostera marina) from San Diego Bay, CA into laboratory mesocosms at two shoot densities; low (400 shoots m-2 ) and high (1200 shoots m-2) and quantified the interaction strengths of three algal grazers on epiphyte abundance and seagrass productivity: the carinate dove shell snail, Alia carinata; grass shrimp, Hippolytecaliforniensis; and amphipods, Gammaridae spp.. The results of this study are not only pertinent to seagrass conservation and management but also to further understanding the principles governing consumer-prey interactions.
† Walker, K.M.1*, Cisneros, A.1, Crossen, S.R.1, Moreno, A.1, Waterston, C.1, Whitcraft, C.R.2, Zacherl, D.C.1
EFFECTS OF OYSTER RESTORATION TECHNIQUES ON OLYMPIA OYSTER (OSTREA LURIDA) DENSITY, SHELL LOSS, AND INVERTEBRATE COMMUNITY COMPOSITION
1 – California State University Fullerton, 2 – California State University Long Beach
The effectiveness of different techniques for restoring Olympia oyster, Ostrealurida, beds has not been systematically evaluated. Further, this oyster’s role as an ecosystem engineer has not been explored; we understand little about whether this species’ restoration will return ecosystem services. We examined which restoration techniques would be most effective for restoring oysters while preventing shell loss and promoting community diversity in Newport Bay, CA by constructing replicate (n=5) 2m X 2m shell beds of 4 treatment types of two thicknesses (4cm versus 12cm) and two levels of consolidation (bagged versus loose shell). After two years, density of adult oysters did not differ among shell bed treatments, but there was an increase in density relative to controls and adjacent reference sites for all treatments except 4-cm loose shell beds. Twelve-cm thick shell beds received the greatest number of oyster recruits and retained the highest % cover of shell. After one year, community diversity increased on all plots, including controls. Infaunal and epifaunal community composition shifted on shell beds, with declines in polychaetes and oligochaetes and increases in hard-bodied invertebrates (e.g., bivalves, isopods) relative to controls. In conclusion, thick shell beds maximize oyster success while minimizing shell loss.
† Walkiewicz, J.A.*, Bassett, M.K.
DISTRIBUTION OF BRACHIOPOD (BRACHIOPODA) BEDSON THE CONTINENTAL SHELF OF CENTRAL CALIFORNIA THROUGH ROV VIDEO IMAGERY
Institute for Applied Marine Ecology, California State University, Monterey Bay
The Monterey Bay National Marine Sanctuary (the Sanctuary), along the central coast of California, provides habitat structures. An important habitat viewed in the Sanctuary is a biogenic structure beneficial to marine life such as rockfish and invertebrates. The species brachiopods, phylumBrachiopoda, are bottom dwelling; sessile organisms that congregate in patches varying form a couple to thousands of individuals. Congregating in beds, brachiopods provide important refuge for fishes and mobile invertebrates to associate with, protecting them from predators and bottom currents. July 2013, video imagery was collected of the seafloor using a remotely operated vehicle, (ROV); within 4 transect locations along the northern and southern edges of Monterey Bay. Brachiopod “beds” were found at 3 out of the 4 transect locations; Davenport, Point Lobos and the Ascension/ Año Nuevo Canyons. Beds were categorized into 3 density level categories: low, moderate and high. Low-density levels represented <30% with seafloor greatly visible, moderate represented 30%-60% with few area of the seafloor visible and high represented >60% with little to no seafloor visible. Brachiopods (phylum Brachiopoda) can occur in dense beds spanning 10s of square meters or greater. The precise geo-referencing of brachiopod beds and further exploration of the organismal associations with those beds, will inform on-going management of Essential Fish Habitat in the Monterey Bay National Marine Sanctuary.
† Yorke, C.E.*, Miller, R.J., Page, H.M.
IS KELP DETRITUS A SIGNIFICANT FOOD SOURCE TO KELP FOREST SUSPENSIONFEEDERS?
Marine Science Institute, University of California Santa Barbara
Subtidal suspension feeders graze on abundant phytoplankton, but have been widely postulated to also assimilate kelp-derived carbon delivered as detrital particulate organic matter (POM). If kelp detritus is a viable food source for suspension feeders, it could be particularly significant during seasonal declines in nutrient concentrations and consequently phytoplankton production. However, direct evidence of kelp detritus assimilation by suspension feeders is scarce: most inference has been based on stable isotope analyses which are often based on untested assumptions. To more directly address this problem, we designed an experiment to assess suspension feeder utilization of naturally occurring kelp detritus when phytoplankton are either abundant or scarce. We maintained several species of reef suspension feeders in flow-through tanks and manipulated their food supply through two treatments: kelp detritus (present or not) and phytoplankton (present or not). We measured growth and tissue isotope composition of the suspension feeders as they were exposed to these treatments over a period of three months. To measure the supply of suspended food particles available to the animals, we monitored chlorophyll, kelp abundance and quality, and POM δ13C and δ15N in the tanks. The results of this study help directly illuminate the role of kelp in subtidal food webs.
Beets, J.1*, Beavers, S.2, Brown, E.2, Kelly, E.3, Kramer, L.1, Krosky, K.1, Smith, J.E.3
ENHANCED ALGAL GROWTH AND INCREASED bENTHIC GRAZING ASSOCIATED WITH SUBMARINE GROUNDWATER SEEPS on the Kona Coast, Hawai‘i
1 – University of Hawai‘i at Hilo, 2 – U.S. National Park Service, 3 – Smithsonian Institute of Oceanography
Nutrients derived from upland terrestrial sources are delivered to coastal regions by groundwater and released from nearshore seeps but also across the seascape from benthic substrate, including coral reef habitats. The natural nutrient concentrations in groundwater are greatly altered by anthropogenic inputs and can result in nearshore nuisance algal growth, invasive algal bloom, and even phase shifts. On the dry, leeward (Kona) coast of Hawai‘i Island and on the Kalaupapa peninsula on Moloka‘i, we have documented greater algal growth and greater grazing rates associated with groundwater seeps with greater nutrient concentrations than at control stations. The increased algal growth at both sites is intensively grazed by herbivores, resulting in algal turf-dominated communities. The algal community structure varies greatly among study sites at Kaloko-Honokohau NHP on the Kona coast, Hawai‘i, and Kalaupapa NHP on Moloka’i, apparently due to differences in the grazer guilds. Fortunately, grazer densities are sufficient at our study to control macroalgal overgrowth, as observed at other locations in Hawai‘i. These results will be very useful for successful marine management of nutrient loads and grazer densities.
Blackwell, R.C.1*, Craig, S.F.1, Mackie, J.2
INVASIONS WITHIN HUMBOLDT BAY, CALIFORNIA BY CRYPTIC SPECIES OF BRYOZOANS (WATERSIPORA SPP.): SPATIAL AND TEMPORAL DOMINANCE BY THREE CLADES
1 – Humboldt State University, 2 – San Jose State University
Bays and harbors worldwide are rapidly being invaded by exotic species. Tracking these invasions is sometimes complicated by cryptic species. Untangling the identities of cryptic species allows one to reveal initial successful invasions, as well as subsequent spread. We focused on the exotic encrusting marine bryozoan Watersipora spp. and hypothesized this genus occupies different regions within Humboldt Bay, California. To test this hypothesis we collected tissue from colonies growing in the intertidal and subtidal regions of the bay on floating dock systems. Species specific cytochrome oxidase I fragments from multiplex-PCR were analyzed to construct a GIS map of species distribution within the bay. Results reveal three species of Watersipora inhabiting Humboldt Bay: (1)Watersipora Clade A is predominately found in the northern part of the bay, while (2) Watersipora Clade B is found in the south. The third (3),Watersipora “New Species” is found in both regions and comprises the vast majority of invasive bryozoans in this bay. These patterns, along with additional mapping done all along the California coast, suggest differential survival of cryptic species due to different microhabitat conditions. Hence identification of cryptic species may help to reveal patterns of invasions that can reflect pre-adaptations of the invaders involved.
Blando, M.N.1*, Lapota, D.2
RECOVERY TOOL FOR THE ENDANGERED BLACK ABALONE ON THE CALIFORNIA CHANNEL ISLANDS
1 – San Diego State University, 2 – SPAWAR Systems Center Pacific
In 2009, California State and Federal agencies declared the black abalone (Haliotis cracherodii) endangered. Fertilization and recruitment rates of naturally occurring H. cracherodii are critically low due to the low density of reproductive individuals. This makes it difficult for H. cracherodii populations to recover from pressures such as Withering Foot Syndrome and human harvesting, and restoring wild populations is therefore crucial. Spawning success in laboratory settings is often low, which is why conditioning and spawning techniques need to be investigated in order to begin restoration efforts. In fiscal year 2013, Space and Naval Warfare Systems Center Pacific and Department of Defense Legacy Resource Management Program initiated a program investigating conditioning, spawning and settling of black abalone. From February 2013 to September 2013, SSC Pacific housed12 adult black abalone that have gained a combined 753 grams, and each individual’s gonad size has also increased. We are now investigating how different diets impact growth and gonad development in adult black abalone. Finally, we will induce spawning and test the potential synergistic effect of parental diet and larval rearing temperature on post-larval settlement success, with the ultimate goal of developing protocols that will enhance the recovery of this species.
Brinkman, A.P.*, Erisman K.L.*, Mize, H.S., Zias, K.J., Anderson, S.
SPIDERS AS METRICS OF ECOSYSTEM FUNCTIONS
Pacific Institute for Restoration Ecology – California State University Channel Islands
Little arthropod research has been conducted within Southern California salt marshes. Our previous work has shown spiders (order Araneae) are apparent apex predators within this arthropod community and may therefore be critical components of these systems. We surveyed coastal wetlands spanning reference (e.g. Mugu Naval Base), degraded (e.g. Ormond Beach) and restored (e.g. Ash Avenue) salt marsh. Previous sampling (in 2011) showed the frequency of spiders to be greater in degraded salt marshes compared to restored marshes. Our 2013 sampling effort is still on going, but preliminary analyses shows strong support for this spider pattern and implies that this spider response is a robust and general aspect of ecosystem response across time and space. We therefore suggest that monitoring the arachnid community will afford robust measure of the overall functioning and “health” of this complex and dynamic ecosystem.
Chilin, D.1*, Reynoso, V.1, Miller, L.2
SPECIES-SPECIFIC RESPONSES TO INCREASING ENVIRONMENTAL VARIABILITY ARE DRIVEN BY DIFFERENCES IN PHYSIOLIGICAL PERFORMANCE CAPACITY
1 – California State University, Long Beach, 2 – Hopkins Marine Station of Stanford University
Anthropogenic global warming is a major driver of changes in population dynamics, species interactions, and community structure from local to global scales. Changes in average temperature have already been implicated in geographic range shifts of many species and increasing temperature variability is likely to be an additional source of disturbance, as it increases the risk that species’ tolerance limits will be exceeded. Direct effects of thermal variability on individual fitness are mediated through physiological sensitivities. We measured metabolic rates in air as a function of temperature for a guild of congeneric grazing limpets at Hopkins Marine Station, Pacific Grove, CA. In general, thermal performance curves were nonlinear and asymmetric, such that metabolic rate rose gradually with temperature to a maximum at some intermediate value and then dropped quickly at higher temperatures. Coupled with a novel experimental approach to manipulate temperature variability of limpets during aerial exposure in the field, our data suggest that characteristic differences in physiological performance may be a key determinant of species-specific responses to future environmental conditions.
DOES SIZE MATTER? A STUDY ON SOCIAL BEHAVIOR IN FEMALE LEOPARD
SHARKS, TRIAKIS SEMIFASCIATA
California State University Northridge
Behavioral studies are very common among many terrestrial and aquatic vertebrates, but very few have dealt with oceanic predators. Social interactions play a major role feeding and reproduction, which are critical for the survival of an individual. Leopard sharks, Triakis semifasciata, are a common predator in the coastal waters of California. Social behaviors have been studied in bonnethead shark, Sphyrna tiburoand the smooth dogfish, Mustelus canis showing that dominance is correlated to size. I asked the question, does size affect the behaviors of leopard sharks and hypothesized that behaviors exhibited by T. semifasciata are dependent on shark size. Underwater observations were carried out at Big Fisherman’s Cove, Santa Catalina Island, CA on snorkel, and social interactions among female sharks were recorded using high definition video. The main interaction looked for was a shark giving way to another shark, which has been used in other shark species. The statistical analysis showed that 46% of the time that there was a significant relationship between behavior and size (R2=0.461) and a Pearson’s Correlation Coefficient showed a significant correlation between dominant/subordinate behavior and their size (r=0.6794, df=20, p<0.001). This lead to the conclusion that dominance in female leopard sharks is associated with size.
Dao, K.1*, Carpenter, R.C.2
POTENTIAL EFFECTS OF OCEAN ACIDIFICATION ON CALCIFICATION AND INTERACTIONS AMONG CORAL REEF CRUSTOSE CORALLINE ALGAE
1 – California State University, Northridge, 2 – California State University, Northridge
High anthropogenic CO2 emissions have led to ocean warming and acidification (OA) and are predicted to negatively affect marine organisms. Coral reefs host a diversity of species and crustose coralline algae (CCA) are calcifiers that have important ecological roles on reefs. In back reef in Moorea, French Polynesia there are three common species of CCA that interact competitively in a predictable hierarchy. We tested the hypothesis that elevated pCO2 would differentially affect CCA species growth and would influence the outcomes of competitive interactions. Communities of CCA species growing on PVC plates were placed in treatments of lowered and elevated levels of pCO2 for 21 days. Calcification of the CCA community was measured using buoyant weight and outcomes of competition were determined from image analysis of photographs. Calcification rates of CCA communities in elevated pCO2 were lower than those exhibited under ambient and lowered pCO2. In ambient and lowered pCO2 treatments, Porolithon onkodes was the most competitive. However, in the elevated pCO2 treatments Lithophyllum flavescensbecame the dominant species. These results suggest that CCA dominated communities will exhibit lowered calcification as OA proceeds and that CCA species composition on coral reefs may shift in a future, more acidic ocean.
DeBrish, A.M.*, Adams, N.L.
IMPACT OF MATERNAL EXPOSURE TO ULTRAVIOLET RADIATION ON DEVELOPMENT AND BIOCHEMISTRY OF PURPLE SEA URCHIN OFFSPRING
California Polytechnic State University, San Luis Obispo
Marine organisms exposed to solar ultraviolet radiation (UVR) experience physiological stress including molecular damage. Adult organisms use avoidance, protection and repair to protect themselves from UVR. For broadcast spawning organisms, the larval stages, which are often unable to employ the same defense strategies as the adults, can be most susceptible to UVR damage. One defense employed by broadcast spawning organisms is maternal investment of protective compounds into their eggs before release into the water column. Our lab has demonstrated UVR exposure of embryos causes delays in development and morphological abnormalities. In this study, we use the purple sea urchin, Strongylocentrotus purpuratus , to examine effects of UVR on maternal investment. We are exposing or protecting adult sea urchins from UVR using acrylic filters for at least 4 months before inducing spawning. Eggs are sampled to determine whether there are differences in biochemistry or the proteome between maternal treatments. Remaining eggs from the two different maternal treatments are fertilized and either exposed to or protected from solar UVR resulting in four total treatments. These embryos are examined for differences in developmental end points and analyzed for differences in growth and development between treatments to determine effects of maternal investment.
Didden, C.1*, Lenz, E.A.2, Edmunds, P.J.2
EXPERIENTIAL ECOLOGICAL INVESTIGATIONS AS A VEHICLE COUPLING TEACHING AND RESEARCH IN HIGH SCHOOLS AND UNIVERSITIES
1 -Viewpoint School, 2 – California State University
K-12 science programs are implementing inquiry-based lessons to expose students to the scientific process and climate change biology. At the same time, STEM faculty are being encouraged to develop outreach activities involving schools. Over the last 8 years we have developed an outreach program that satisfies these criteria through a program between, Viewpoint School, and California State University, Northridge. We have focused on coral reefs, but now are extending the program to subtidal environments of California. The program has evolved through four phases: 1) fostering interactions among educational partners, 2) developing curricula through research exploiting hands-on problem solving skills, 3) completion of scientific activities in the classroom and field, and 4) engaging students in the scientific process through field work, scientific conferences and the publication process. These efforts have led to a self-sustaining program promoting interactions among school children, undergraduates, graduate students, k-12 educators and university faculty that are promoting STEM careers and generating peer-reviewed publications.
Ginther, S.G.1*, Culver, C.S.1,2, Brooks A.J.1
POTENTIAL BIOCONTROL AGENTS FOR AN INVASIVE FRESHWATER MUSSEL
1 – Marine Science Institute, University of California Santa Barbara, 2 – California Sea Grant, University of California San Diego
Quagga mussels, Dreissena burgensis, are an invasive freshwater pest that recently (2007) invaded Southern California and represent a significant threat to the region’s freshwater ecosystems. Additionally, quagga mussel infestations have affected the delivery of water to agriculture and more than 20 million residences. Using a series of aquaria experiments, we assessed the functional response rates of three molluscivores, redear sunfish, Lepomis microlophus, red swamp crayfish, Procambarus clarkii, and channel catfish, Ictalurus punctatus, to evaluate their potential as biocontrol agents for quagga mussels. Quagga mussels were provided to test animals of each predator species in varying abundances ranging from 1-40 individuals. Sunfish (TL = 132-244 mm), large (CL = 47-55mm) and small crayfish (CL = 25- 29 mm) consumed maxima of 37, 59 and 28 mussels over 48 hours, respectively. By contrast, individual channel catfish (TL = 215-412 mm) consumed only one or two mussels at most. Notably, not all individuals of mussel predators consumed quagga mussels. Our results suggest that redear sunfish and red swamp crayfish may serve as potential biological controls for quagga mussels, but additional studies are needed to assess variation in consumption among individuals and consumption rates under natural conditions.
Griffiths J.S.1*, Duffy T.A.2, Chesney E.J.2
THE EFFECTS OF CRUDE OIL ON CRITICAL LIFE STAGES IN MARINE LARVAE: A COMPARISON OF INVERTEBRATES AND VERTEBRATES
1 – Pacific Lutheran University, 2 – Louisiana Universities Marine Consortium
The 2010 Macondo oil spill directly killed many marine organisms, but there were other unknown sublethal effects. Blue crabs (Callinectes sapidus) and bay anchovy (Anchoa mitchilli) are ecologically and commercially important species in the Gulf of Mexico. Molting in blue crabs and swim bladder development in bay anchovy were investigated by exposing larvae to crude oil. Blue crab zoea exposed to water-accommodated fractions (WAFs) had significantly larger carapace lengths compared to controls. These results suggest that oil is interfering with the development of zoea by causing them to be physiologically stressed and increase their rate of molting. Bay anchovy swim bladder development occurred over multiple days and was classified into four stages. Complete development and inflation of the bladder was first observed on day 6-8. Growth rates were highly varied but they were significantly correlated with length and age. Exposure of anchovy embryos (18 hours post-fertilization) to WAFs resulted in significantly smaller lengths by day 7, although bladder volume was not significantly affected. Swim bladder volume and lengths of exposed embryos were highly varied, thus any effects to bladder development may have been masked by the wide variation in growth and development.
Henkel, S.K.*, Politano, K.K.
IDENTIFYING INVERTEBRATE ASSEMBLAGES ON THE PNW SHELF FOR HABITAT MAPPING AND ENVIRONMENTAL ASSESSMENT
Hatfield Marine Science Center, Oregon State University
As demands for ocean space increase and diversify (marine reserves, offshore renewable energy, offshore aquaculture), classification of marine habitats and mapping of biological assemblages have become a priority for natural resource agencies. Projects currently underway at OSU include surveys of benthic invertebrate communities and habitats in the shelf waters off the Pacific Northwest to assess baseline biological and geological patterns in areas of potential marine renewable energy development and marine reserve establishment. The approach uses a combination of benthic sampling with cores, ROV/camera systems, and multibeam mapping to characterize communities and habitats. Efforts are focused on both soft and hard bottoms at depths from 30 to 130 m and surveys are designed to allow for local and regional comparisons. The majority of macroinvertebrate taxa were associated with high-relief rocks, these taxa further differentiated between flat and ridge rocks. Low-relief unconsolidated habitat was most associated with motile invertebrates, and fine-sediment substrata mixed with boulders or gravel yielded unique invertebrate associations. In sedimentary habitats, as expected, differences in infaunal invertebrate assemblages were driven primarily by depth and grain size. However, while species diversity increased at deeper depths and smaller grain size, local heterogeneity was higher in shallower sites with larger grain size.
Iyer, P.*, Mackie, J.
COPPER UPTAKE RATES OF COMMON INVERTEBRATES IN MARINAS, AN ENVIRONMENT AFFECTED BY BOATS AND BOAT RELATED INTRODUCTIONS
San Jose State University
Copper is a common toxic component of antifouling paints but precise effects of copper leaching form boats are still little researched. Some invasive marine species show tolerance of copper, indicating adaptations. Our goal general was to determine biological effects of copper at concentrations seen around ship hulls and in marinas using biologically relevant dosing. In 2012, using standard copper paints, we examined copper tolerance of fouling species at multiple marinas in California via dissolved ions from two cuprous-oxide based paints emitted across and unpainted settlement surface. In a 4 week dosed experiment in San Diego harbor we found higher abundance of the serpulid Hydroides sp in the presence of copper dose, as compared to non-dosed control environments indicating successful competition in the present of the pollutant. This leads to the question: do copper tolerant species absorb more copper per body mass as a part of copper detoxification mechanisms? Using induction coupled plasma-atomic emission spectrometry (ICP-AES) we are measuring the uptake of copper in different species to determine if there are significant variations in copper absorbance rate. Organisms we are assaying include serpulid polychaete worms, ascidians, and bryozoans.
SIX STEPS TO ENHANCE YOUR ENGAGEMENT STRATEGY
Birch Aquarium at Scripps Institution of Oceanography, University of California San Diego
Environmental organizations increasingly emphasize stewardship and behavior change in their program goals to bolster public conservation action. Because many human behaviors do not favor conservation, public programs need sophisticated approaches to interpret socio-ecological problems. Here, a six step program planning methodology uses integrative research and values-focused decision points to aid users in engaging public audiences. Benefits include the ability to narrow communication priorities and address emerging conservation issues. Steps 1-3 use integrative research to guide topic selection and conduct literature reviews. Steps 4-6 explore how to align research insights with project goals and engagement strategies. The topic of marine debris is used to illustrate how synthesizing research from marine ecology, sustainability science, and social psychology can promote stewardship and mitigate barriers to pro-conservation behaviors.
Kawana, S.K.1*, Catton, C.A.1, Rogers-Bennett, L.1,2
DISTRIBUTION OF THE BORING SPONGE, CLIONA CELATA, INFECTING THE RED ABALONE IN NORTHERN CALIFORNIA
1 – California Department of Fish and Wildlife, 2 – Bodega Marine Laboratory: University of California Davis
Infestations of boring sponge can damage the shells of calcareous molluscs causing them to become weak and brittle, potentially impacting growth and mortality rates. Red abalone (Haliotis rufescens) host a species of boring sponge, Cliona celata, that is widely distributed, however local patterns of infestation are undescribed. To investigate the presence of C. celata on red abalone, fishery-dependent samples were collected at six sites in Sonoma and Mendocino counties during peak low tides (popular fishing days) in April, May, and June of 2011 and 2013. All abalone examined were legal size of 7 inches (178mm) or larger. We also conducted fishery-independent scuba surveys to examine the infestation patterns across a wider range of abalone sizes. We found C. celata had infected a significantly greater proportion of the fished abalone at Fort Ross, Van Damme State Park, and Mackerricher State Park, whereas Moat Creek, Point Arena, and Glass Beach had low infection rates. The probability of C. celata infection increased with abalone size. Identifying C. celata presence within fishing grounds as well as the size distribution of infected abalone is an important step in detecting potential impacts of C. celata on populations of red abalone which support an important recreational fishery.
Kurniasih, E.M.1,4, Masriana1,5, Schmeltzer, E.R.2*, Setyawan, E.3, Wulandari, R.1
RELATIVE ABUNDANCE AND DIVERSITY OF MOTILE FAUNA ON DEAD POCILLOPORA CORAL HEADS: THE EFFECTS OF XENIA (OCTOCORALLIA) AND BIOEROSION
1 – Indonesian Biodiversity Research Center, 2 – Moss Landing Marine Laboratories, 3 – Conservation International Indonesia, 4 – Bogor Agricultural University, 5 – Papua State University
We have used dead Pocillopora coral heads to assess if and how overgrowth of the soft coral Xenia and the bioeroding sponge Cliona affects diversity and abundance of motile organisms on coral patch reefs.Xenia and Cliona were studied as they are implicated in reef degradation in Pemuteran, Bali, Indonesia. Both species are typically found on degraded reefs, but it is unknown whether they are a cause or consequence of the degraded condition. In general, relative diversity and abundance of motile fauna increased as Xenia and Cliona coverage decreased. Diversity was strikingly greater on coral heads free ofXenia. The trend applies to Cliona presence as well, but with a less marked tendency, leaving us to believe that Xenia plays a greater role in degradation. The implication of these trends for coral patch reefs and other coral reefs in Indonesia is discussed.
LaScala-Gruenewald, D.E.1*, Freeman, M.B.2
CHARACTERIZING LIMPET FORAGING WITH POWER LAW STATISTICS
1 – Hopkins Marine Station, 2 – Eckerd College
Foraging is a fundamental way in which organisms interact with their environments. In the intertidal zone, herbivores like limpets face complex and so far undescribed foraging landscapes. Optimal foraging theory hypothesizes that when food sources are sparse, a power law model with an exponent of two describes the most efficient foraging behavior. In this study, we employed maximum likelihood statistics and a novel field set-up to characterize and compare the foraging behavior of three limpet species: Lottia gigantea, Lottia austrodigitalis and Lottia scabra. To do this, we used a waterproof camera to photograph limpets once a minute for two weeks. We then tracked the limpets using ImageJ, and fit three statistical models – power law, exponential and log normal distributions – to the tracks. The best models for each limpet and each species were also determined. Our results suggest that limpet foraging is suboptimal for an environment with sparse resources, and that different species of limpets use statistically different foraging strategies. These differences may be influenced by environmental factors, such as wave exposure or rock topography.
McCormick, T.B.1, Buckley, L.M.2, Mendoza, J.3*, Contreras, F.3*
EFFECTS OF REMOVAL OF INVASIVE PLANTS ON THE WETLAND COMMUNITY AT ORMOND BEACH
1 – Channel Island Marine Resource Institute, 2 – University of the Virgin Islands, 3 – Oxnard College
Ormond seasonal wetlands in Oxnard, California, connect to the Mugu Lagoon wetlands making this the largest coastal wetland in Southern California. Restoration efforts are underway to eradicate non-native plant species to promote native species richness and diversity by increasing increases light penetration and decreasing biomass. This project assessed the effects of removal of Myoporum laetum during the winter of 2012/2013 using 50-m point-quadrat transects for plants and walking visual surveys for birds. The most dramatic effect of removal of M. laetum was a decrease in mean plant height (90 cm, 2012; <40 cm, 2013). Plant species richness increased after invasive removal (17 before; 22 after); however, a decrease in the species richness of birds was recorded (43, before; 21, after) and avian predator species declined from six to zero. The absence of the predatory birds is likely due to loss of perches since the M. laetum represented the only plant over a meter in height. Since this data was collected in an unusually dry year, long-term monitoring is necessary to fully assess the changes in plant diversity and abundance as the expansive soil exposed by removal of M. laetum is colonized by new growth.
McHugh T.A. and Elsmore K.E.*
DISTRIBUTIONS AND HABITAT ASSOCIATIONS OF TWO SEA URCHINS, PARACENTROTUS LIVIDUS AND ARBACIA LIXULA, IN THE NORTHWESTERN MEDITERRANEAN SEA AT STARESO, CORSICA, FRANCE
University of California, Santa Cruz
Understanding the physical characteristics of a habitat allows us to make predictions about species interactions, their distributions, and the relevance to their surrounding community. Previous studies have found that urchins are a viable species for indicating ecosystem health; their sensitivity to both physical and biological changes in their environment make them excellent study organisms for ecosystem conditions. In this study, we conducted a comprehensive survey of the distribution and habitat associations of two urchin species, Paracentrotus lividus and Arbacia lixula, within the harbor of STARESO. Conflicting results from previous studies on diet and habitat occupation of P. lividus and A. lixula, in the northwestern Mediterranean, have left the question of urchin habitat associations unresolved. We characterized depth, substrate, and primary placeholders using uniform point contact (UPC) methods. The swath method was used to measure urchin density and distribution. SYSTAT and SURFER programs were used to create a bathymetric map, and to determine if the spatial location of A. lixula and P. lividus differ. ANOVA results showed significant variations between the urchin species in density, spatial location, biotic and abiotic habitat preference. Examining the roles of P. lividus and A. lixula within a community will allow us to make predictions about STARESO harbor’s ecosystem dynamics.
Negrete, M.E.*, Voigt, E., Hovel, K.A.
SEAGRASS STRUCTURAL COMPLEXITY EFFECTS ON MESOGRAZER BIODIVERSITY AND EPIPHYTIC ALGAE GROWTH
Department of Biology and Coastal & Marine Institute, San Diego State University
Seagrasses provide vital habitat for many ecologically and commercially important species, but are experiencing unprecedented declines due to anthropogenic effects such as eutrophication and overfishing. Nutrient loading promotes growth of epiphytic algae that outcompetes seagrass for sunlight. Recent evidence suggest that effects may be compounded by removal of top predators that are key players in trophic cascades, which may result in decreased mesograzers. Habitat complexity, such as dense seagrass shoots or high epiphyte biomass may protect mesograzers from predation, reducing top-down effects. Our objective was to determine whether seagrass structural complexity (shoot density) influences mesograzers abundance, biodiversity, and growth of epiphytes on seagrass blades. In San Diego Bay, CA, we manipulated eelgrass (Zostera marina) shoot density in eelgrass plots and measured abundance of epiphytic algae (Chl a), the abundance and diversity of mesograzers. We found that low shoot density plots had higher epiphyte biomass, which was contrary to our hypothesis that high shoot density plots would have reduced epiphyte biomass due to protection of mesograzers from predators.
Neu, A.T.1*, Donham, E.2, Smith, J.E.3, Hamilton, S.L.2
EFFECTS OF ACIDIFICATION ON BENTHIC COMMUNITY COMPOSITION AND SPECIES-SPECIFIC GROWTH RATES
1 – San Diego State University, 2 – Moss Landing Marine Labs, 3 – Scripps Institution of Oceanography
Ocean acidification (OA) due to increasing carbon dioxide emissions will likely have large impacts on marine biodiversity and ecosystem function. However, relatively few studies have investigated how intact communities will change in response to decreased pH and carbonate availability. In order to better understand the effects of OA on community composition, species abundance, and species-specific growth rates of abundance calcifying taxa, we deployed settlement tiles in a kelp forest in Monterey, CA to accrue natural mixed invertebrate and algal communities. After one year tiles were brought into the laboratory and reared under ambient conditions (pH ~8.0) and conditions predicted to occur in the year 2100 (pH ~7.6). We hypothesized that the abundance of calcifying taxa will decrease while the abundance of fleshy taxa will increase under decreased pH conditions. We also hypothesized that the growth rates of barnacles, Balanus crenatus, and scallops, Pododesmus macrochisma,would be decreased in decreased pH. Photographs were taken biweekly for the duration of the 5 week experiment. Photographs were analyzed for percent cover at the beginning and ending time points using PhotoGrid software. In addition, surface area of all P. macrochisma and randomly sampled B. crenatus were measured at the beginning and end time points using ImageJ software. Preliminary data shows the effects of current and future pH conditions on community composition on benthic tiles and species specific growth rates of B. crenatus andP. macrochisma.
Neuneker, K.R.1*, Holt, K.A.1, Behrens, M.D.1, Parker, H.C.2, Becker, B.J.2, Vadopalas, B.3, Allen, B.4
OLYMPIA OYSTER SETTLEMENT IN FIDALGO BAY, WA
1 – Pacific Lutheran University, 2 – University of Washington Tacoma, 3 – University of Washington School of Aquatic and Fishery Science, 4 – Puget Sound Restoration Fund
The Olympia Oyster (Ostrea lurida), the only native oyster found on the west coast of North America, has been depleted over time due to over harvesting and other environmental factors. Recently interest has surfaced in reestablishing these populations, including a restoration project in Fidalgo Bay, Washington begun in 2002. In order to assess the distribution and success of this population we investigated variation of settlement of juveniles in space and time. Through placing oyster shells modified to collect settlers at 42 locations within 7 sites, an assessment of their distribution was possible. There was a late July peak in settlement during the 6th week of study; however, this peak was only detectable at the intertidal locations. The results indicate that O. lurida larvae preferentially settled at two intertidal sites, which were nearest to each other and the site of the 2002 restoration seeding effort. This may point to the success of the restoration site as well as support the hypothesis that larvae may settle preferentially to locations with suitable habitat or adult populations. Additionally, rates of settlement were lowest at the mouth of the bay suggesting there may be little dispersal of organisms out of the bay.
Privitera-Johnson, K.M.1*, Lenz, E.A.2, Edmunds, P.J.2
DENSITY-DEPENDENT RECRUITMENT OF GORGONIANS IN ST. JOHN, US VIRGIN ISLANDS
1 – California State University, Long Beach, 2 – California State University, Northridge
The community structure of many coral reefs has changed profoundly in the last 50 years, yet the events receiving attention have involved mostly scleractinians corals, macroalgae, and fishes. Coincident with these changes, it is likely that other taxa also are changing in abundance, and here we focus on gorgonian corals in St. John, US Virgin Islands. In response to recent evidence suggesting that gorgonians are increasing in abundance in several Caribbean locations, including St. John, we tested whether density-dependent recruitment favors population growth of gorgonians. Gorgonian populations were censused on shallow reefs (< 9-m depth) along the south shore of St. John, and the relationship between density of recruits (≤ 4-cm tall) and adults was tested for density dependence. At 10 sites, mean gorgonian density (± SE) varied from 3.3 ± 0.2 to 19.3 ± 1.0 colonies m-2, and the density of recruits and adults were related in a threshold fashion. Positive density dependence of recruitment occurred at < 10 colonies m-2, but thereafter, recruitment declined with further increases in adult density; this relationship also held for the four dominant genera studied. These results suggest that gorgonian populations promote self-recruitment, but eventually their canopy impedes recruitment or post-settlement success.
The design and construction of a low cost recirculating seawater system for student or research use
Monterey Peninsula College
Most colleges and universities do not have access to a flow-through seawater system for their biology laboratories and research needs. The limitations of size, cost, and complexity are barriers that prevent the construction of such systems, and students and faculty often find that the only time they have access to seawater systems are when working at a marine laboratory by the sea. Here I describe the detailed design, parts, cost, build, and operation of a 280 gallon, chilled, filtered, recirculating seawater system, done in a small footprint that can support several touch tables and dozens of small tanks. An itemized lists of all components, sources, and costs will be available.
Roberts, E.A.1*, O’Donnell, M.J.1, Murray, J.W.1,2, Carrington, E.1,3
SEASONAL DYNAMICS OF SEAWATER CONDITIONS AND MUSSEL SHELL STRENGTH IN THE SALISH SEA
1-Friday Harbor Laboratories, University of Washington, 2 – School of Oceanography, University of Washington, 3 – Department of Biology, University of Washington
San Juan Island sits within the Salish Sea estuary complex, and experiences dynamic tidal shifts in water condition. Acidified upwelled coastal water can enter the Puget Sound via the Strait of Juan de Fuca and can combine with brackish water from the Fraser River in B.C., Canada. Here we present a time series of carbonate chemistry from September 2011 to July 2013 as well as a time series of force required to crush a valve of the native Pacific blue mussel (Mytilus trossulus). Seawater carbon dioxide (CO2) was higher than ambient atmospheric CO2 (seawater pCO2 700 ± 103 uatm; pH 7.80 ± 0.06), and transient decreases in CO2 corresponded with the timing of annual spring phytoplankton blooms in 2012 and 2013. Shell strength varied annually; shells were stronger in the winter and weaker in the summer. In comparison, the water was corrosive throughout most the year (winter Ωaragonite 0.95 ± 0.11 s.d.) but less so in the spring (April-June Ωaragonite 1.15 ± 0.14 s.d.). Thus, other factors besides seawater acidity (i.e. growth rate, food availability, or energy allocation to reproduction) may be more important in driving seasonal changes in shell strength of a native mussel in the Salish Sea.
Sanchez, A.*, Hovel, K.
INTERACTIONS OF U.V., LIGHT, AND EPIPHYTES ON SEAGRASS GROWTH
San Diego State University
Seagrasses are marine plants that provide important habitat and other ecosystem services. Unfortunately, worldwide 29% of seagrasses have been lost due to human disturbances. One disturbance is eutrophication, in which adding nutrients to estuaries promotes algal growth. Seagrasses like Zostera marina have high light requirements, however epiphytic algae require little light to grow and can rapidly accumulate, reducing survival and the depth to which seagrasses can grow. But, epiphytes also have the potential to benefit seagrasses at shallow depths by blocking harmful UV radiation. Thus, testing how depth (i.e. light levels) effects the epiphyte-seagrass interaction is essential to better understanding seagrass growth. To test this interaction, seagrass was transplanted from San Diego Bay into outdoor aquaria and seagrass growth was measured under four treatments: full sunlight with and without epiphytes, and shade with and without epiphytes. Exposure to UV was controlled with acrylic sheets placed over aquaria and shade (to simulate light loss due to depth) was controlled with shade cloth. Chlorophyll α from epiphytes was greatest in the no UV treatment, followed by the shade and ambient treatments. Surprisingly, epiphytes had no effect on seagrass growth under ambient conditions; however it positively influenced growth in the no UV treatment.
ECOMORPHOLOGY OF STORM PETRELS ALONG THE PACIFIC COAST OF THE AMERICAS
California State University, Northridge
Storm-petrels are among the smallest seabirds and are characterized by a unique feeding behavior known as pattering, which has been likened to walking on water. The eastern Pacific holds the greatest diversity of storm-petrels and at least nine species breed along the coast of the Americas at Mediterranean lattitudes. Only certain species perform this pattering but the morphological adaptations for this behavior have yet to be quantified. Measurements on the wings, beaks, and hindlimbs from live individuals at their breeding colonies are being gathered to understand morphological correlates for pattering and to see how the distribution of functional types differs between the two hemispheres. Prelimary data suggest that differences in wing loading, aspect ratio, and foot morphology are important functional indicators. This study will contribute to a better understanding of the evolutionary history and diversification of the storm-petrel family and how it has radiated to exploit the oceanic realm in its unique way.
Schiebelhut, L.M.*, Abboud, S.S., Gómez-Daglio, L., Swift, H.F.
QUICK, CLEAN, AND CHEAP? COMPARING DNA EXTRACTION METHODS FOR DIVERSE MARINE TAXA – ONE YEAR UPDATE
University of California Merced
The inclusion of next generation sequencing technologies in population genetic and phylogenetic studies has elevated the need to balance time and cost of DNA extraction without compromising DNA quality. The commonplace CTAB phenol/chloroform extraction has been used to obtain long-term PCR-quality DNA, but creates a methodological bottleneck. We tested eight extraction methods, ranging from low- to high-throughput techniques, on 4 individuals from each of eight marine phyla—Porifera, Cnidaria, Annelida, Arthropoda, Mollusca, Echinodermata, Chordata, and Heterokontophyta. We assessed extraction efficiency, DNA purity, and affordability of each method. Extraction efficiency was measured by PCR amplification of two molecular markers (mitochondrial COI and nuclear Histone 3) at one year post-extraction. DNA purity was quantified using NanoDrop absorbance ratios. Affordability was estimated in terms of time and material expense. Current analyses show differences in DNA purity and PCR success between extraction methods, with PCR success at one year roughly concordant with initial purity. Results also varied by taxon. As expected, the affordable, yet time intensive, low-throughput CTAB phenol/chloroform extraction performed well. In comparison, the higher-throughput AcroPrep PALL glass fiber plate extraction preformed equally well and is one of the most time-efficient and cost effective methods.
Shannonhouse-Wilde, D.R.1*, Berryman, G.K.1*, Wynkoop, L.M.2, Rodriguez, K.A.1*, Raimondi, P.T.1
PRELIMINARY ASSESSMENT OF COMPETITION BETWEEN TWO LABRIDS AS A MODEL SYSTEM FOR MEDITERRANEAN INVASIONS DRIVEN BY CLIMATE CHANGE
1- University of California Santa Cruz, 2- Bodega Marine Lab, University of California Davis
Marine invasions in the Northern Mediterranean have increased in recent decades, due rising seawater temperatures caused by global climate change. Several possible responses that resident species can have subsequent to habitat invasion by an ecologically similar species include resource partitioning, complete competitive exclusion, or no response. In this study we investigated indirect competition between two wrasse species in Corsica, France: the native Coris julis and the southern invader Thalassoma pavo. Specifically, we sought to quantify the degree of overlap in shared resources to better understand how C. julis may be impacting T. pavo. Recording associated depths, substrates, and primary placeholders (biological cover) for individual fish revealed that there was considerable overlap in all aspects of habitat association. T. pavo had a significantly shallower distribution than C. julis (p=0.006) and differed in substrate (p=0.004) and cover (p=0.004) associations. Comparing the frequency of bites taken from different cover types and examining stomach contents, revealed that there was considerable overlap in diet, but that T. pavo and C. julis forage differently with respect to cover types and prey, (p=0.002, p=0.001 respectively). This overlap in diet and habitat preference suggests interspecific competition exists, possibly mitigated by resource partitioning or previously evolved resource preferences.
Sowul, K.*, Garza, C.D.
DIVER BASED VERSUS TIME-LAPSED PHOTOGRAPHIC ESTIMATES OF MPA DESIGN EFFICACY
Division of Science and Environmental Policy, California State University, Monterey Bay
Acquiring survey based estimates of Marine Protected Area performance is a key method through which resource managers can ascertain the efficacy of MPA design and its impact on targeted fisheries. Diver surveys are a common method for acquiring demographic information, such as population size, that can be used to assess the impact of an MPA on individual species. However, dive surveys can introduce bias into demographic data via the behavioral shifts that the presence of divers can introduce into populations present in an MPA. Techniques that minimize behavioral modifications in target species may provide a more accurate estimate of the effect of an individual MPA on targeted species. In this study, we report on the use of diver based and time lapse photographic estimate of MPA performance on the California Spiny lobster (Panulirus interruptus) in the USC Wrigley Marine Reserve. Our study employs the comparison of lobster demographic data collected using nighttime and daytime surveys by research divers as compared with time-lapse photographic surveys completed by installing a subtidal camera and light strobe in the study area that took pictures every 15 minutes throughout high tide. Our results highlight variation in lobster demographic data acquired by our two survey methods.
Spies, B.T., Tarango, B.C.*, Steele, M.A.
LARVAL DURATION, SIZE AT SETTLEMENT, AND GROWTH RATES OF THE ARROW GOBY (C. IOS) AND THE ENDANGERED TIDEWATER GOBY (E. NEWBERRYI)
California State University, Northridge
Little is known about the early life history of the endangered tidewater goby (Eucyclogobius newberryi) and its sister species the arrow goby (Clevelandia ios). Both are found in estuarine habitats throughout the California coast, however, habitat use differs between these two species. C. ios is commonly found in bays and estuaries with marine tidal influence, where E. newberryi prefers more brackish estuaries with some degree of seasonal closure. Here we examine the larval duration, size at settlement, and growth rates of newly settled gobies from eighteen estuaries throughout California. Larval traits were examined by counting and measuring daily bands on the lapillar otoliths from the core to the settlement band. Otolith traits were used as proxies for somatic traits due to the strong linear relationship between otolith radius and standard length for both species. Variability among estuaries in all larval traits was found in both species, likely due to variations in habitat type and environmental factors. Larval traits on average were found to be quite similar in both species, with C. ios exhibiting a slightly longer larval duration (26.1 ± 2.4days compared to 23.9 ± 2.7days), and larger at settlement (77.6 ± 6.4μm compared to 75.6 ± 6.4μm).
Sullivan, J.M.1*, Ayres, M.P.2, Garnas, J.R.3
Spatial patterns and reproductive success of an invasive woodwasp in New York state
1 – Oregon State University, 2 – Dartmouth College, 3 – University of Pretoria
The ecological effects of introduced species are often minimal but sometimes profound. Predicting which introductions will be consequential is a challenge for ecologists and natural resource managers. We applied ecological theory to evaluate the trajectory of the recent invasion of North American forests bySirex noctilio, a European pine woodwasp which has caused massive tree mortality in the southern hemisphere. In New York State, we found evidence of destabilizing positive feedback in the population dynamics of S. noctilio. However, we did not find spatial autocorrelation in S. noctilio abundance, as would be expected if landscape pestilence arises from positive demographic feedbacks. We found evidence of natural controls on S. noctilio populations from interactions with indigenous species. The impacts of S. noctilio in North America will be modest if it mainly reproduces within European Scots pine, its natural host. Indeed, parental females were more common in Scots pine stands than red pine stands, but there were equal numbers of progeny emerging from the two species. The expected future for S. noctilio in North America remains unclear; there would be value in continued studies of the relations between invasion ecology, insect entomology, and forest management in this system and elsewhere.
Tinker, A., Cebrian-Paskell, B.M.*, Cross, C., Esgro, M.
WHAT FORTY YEARS OF FISH CAN TELL US ABOUT THE SOUTH SAN FRANCISCO ESTUARY
Marine Science Institute
The Marine Science Institute (MSI) in Redwood City, California is a non-profit educational institution that instructs participants in the ecology and conservation of the San Francisco Estuary (SFE) through experiential learning programs. Daily field trips in the southern SFE aboard an oceanographic research vessel form the core of MSI’s curriculum. Three or four fish trawls are conducted each voyage, and trained fish interns collect data on the fish caught in each otter trawl net tow. Fish are identified to species, the standard length is recorded, and individuals of the same species are grouped into size classes and counted. We have collected data from nearly 10,000 trawls since MSI’s founding in 1970. Our initial discoveries include a slight increase in total fish catch per trawl and fluctuations in the diversity of more than 130 species recorded. We found a significant negative correlation between Northern anchovy and Shannon’s diversity index. Our records reflect the Pelagic Organism Decline (POD) from 2001-2009, well documented in the northern reaches of the SFE.
Tortolani, J.*, Silva, M.*
GENOMIC INVESTIGATION OF THE HOLOTYPE SPECIMEN OF THE RED ALGAL SEAWEED PORPHYRA SANJUANENSIS (BANGIALES, RHODOPHYTA)
The red seaweed Porphyra sanjuanensis was described to accommodate large, rubbery, brown to reddish brown thalli native to San Juan Island, Washington, USA. The species was said to contain cells with a single chloroplast and haploid karyotype of three. Most distinctive however, was its mode of reproduction, in which the gametophyte generation liberates aplanospores that recycle directly into new haploid blades. Based on anatomical and morphological similarities, as well as protein evidence, P. sanjuanensis was reduced to synonymy under Pyropia perforata, a species that reproduces sexually, and contains two chromosomes per cell. The purpose of this investigation was to test the accuracy of the current classification by employing next generation sequencing technologies. Using 4 x 4 mm2 of material from the holotype specimen, we assembled the complete mitochondrial (40,042 bp) and chloroplast (189,788 bp) genomes of Po. sanjuanensis and compared them to the circular genomes of Py. perforata and other species of Pyropia and Porphyra. Our results refute the placement of Po. sanjuanensis with Py. Perforata, and support the reinstatement and comb. nov. of the name Pyropia sanjuanensis. These data demonstrate that genomic DNA from archival type materials can be used to solve modern systematic problems.
Vaughn, D.1*, Carrington, E.2,3*
EFFECTS OF THERMAL STRESS ON REPRODUCTIVE OUTPUT IN INTERTIDAL SNAILS
1 – California State University, Northridge, 2 – University of Washington, 3 – Friday Harbor Laboratories
Physiological stresses can have cumulative and synergistic consequences for organisms. Such stresses need not be immediately lethal to be ecologically significant. For instance, thermal stress may reduce reproductive output, and subsequently affect species abundance and distribution. In this study we manipulated low tide aerial temperature to test the effect of increased body temperature on reproduction in the intertidal predatory whelk, Nucella ostrina. For 30 days, we subjected male and female whelks to elevated air temperatures of 28o, or 20oC in a control group, at each low tide. After applied heat stress, we paired individuals for reproduction under benign thermal conditions in all four possible sexes by treatment combinations. Regardless of whether the male, the female, or both the male and female of a pair were previously heat stressed, prolonged exposure to elevated air temperatures caused a significant reduction in the number and volume of deposited egg capsules compared with capsules deposited by unstressed females mated to unstressed males. Fewer and smaller egg capsules indicate a decrease in fecundity and in maternal investment and may correlate with fewer or smaller offspring at hatching. Either way, these results demonstrate that prolonged thermal stress can significantly alter reproductive output of N. ostrina and suggest important consequences for the performance of this ubiquitous intertidal whelk across generations.
Villalobos, C.1*, Pierson, J.2
HYPOXIC IMPACTS ON EGG RESPIRATION RATES OF THE COPEPOD ACARTIA TONSA
1-California State University, Monterey Bay, CA, 2- University of Maryland Center for Environmental Science
The Chesapeake Bay has experienced extensive areas of hypoxia (< 2mg O2 L-1) in the past half-century as a direct result of eutrophication. The copepod Acartia tonsa serves as a valuable prey item to higher trophic levels in the Chesapeake Bay and past studies have detected negative hypoxic effects on reproductive and egg development rates. However, the physiological mechanism causing these negative effects in A. tonsa are not well understood. The goal of this study is to examine if lowered A. tonsarespiration rates may be a potential physiological mechanism impacted by hypoxia in the Chesapeake Bay. Egg development rates and hatching success of A. tonsa will be measured in hypoxic (> 2mg/L O2) and fully oxygenated (~7.99mg/L O2) waters. Lowered respiration rate in hypoxic conditions may contribute to decreases in A. tonsa egg production, sinking rates, and ultimately egg hatching success. Results of this study will examine how future A. tonsa populations will be impacted in a changing environment as well as determining the future health of their predators.
Walovich, K.A.*, Ebert, D.A.
THE ‘SPOT A BASKING SHARK’ PROJECT
Pacific Shark Research Center, Moss Landing Marine Laboratories
The occurrence of trans-equatorial migrations of the basking shark (Cetorhinus maximus) has recently been described, yet global seasonal patterns of distribution have yet to be elucidated. Filling in vital knowledge gaps will help inform the best recovery plan to rebuild the basking shark population in the eastern North Pacific, which has been designated a “Species of Concern” by NOAA’s National Marine Fisheries Service. The ‘Spot a Basking Shark’ Project is a collaborative effort to investigate the abundance, distribution, and population status of basking sharks in the eastern North Pacific. The project employs a web-based reporting system for the public to record sightings, utilizes satellite tags to improve understanding of essential habitat and geographic range, and obtains additional information on life history and patterns of occurrence by data–mining existing records. Have you seen a basking shark? Report your sighting on our website: http://psrc.mlml.calstate.edu/current-research/basking-shark/
Waltz, G.W.*, Robbins, I.C., Needles, L.N., Wendt, D.E.
AN ASSESSMENT OF WATER QUALITY PARAMETERS IN TWO CENTRAL CALIFORNIA MPA MONITORING SITES AND THEIR EFFECT ON CATCH PER UNIT EFFORT
Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo
Since 2007, the California Collaborative Fisheries Research Program (CCFRP) has been monitoring the nearshore groundfish catch per unit effort (CPUE) in south central coast Marine Protected Areas (MPAs) using standardized recreational hook-and-line fishing methods. In 2013, we incorporated water column sampling of conductivity, temperature, depth, nitrate, dissolved oxygen, chlorophyll fluorescence, and turbidity in two MPA sites and two adjacent reference areas. CCFRP fishing trips occurred in the Piedras Blancas State Marine Reserve (SMR), the Point Buchon SMR, and adjacent non-protected waters on 16 occasions between July and September 2013. A mobile water quality unit was cast concurrently during timed fishing drifts such that each drift CPUE from various monitoring locations had an associated water column sample. From these data sets we examined whether; 1) there were differences in the environmental parameters between MPA and reference sites, and 2) there was any correlations between fine spatial and temporal scale environmental factors and CPUE. These data will be used to provide an assessment of water quality parameters in the MPAs compared to the non-protected areas and to examine the relationship between conductivity, temperature, nitrate, dissolved oxygen, chlorophyll fluorescence, and turbidity on CPUE in protected and reference areas.
Wormald, C.L.*, students of ESRM 462, Anderson, S.S.
EVALUATING PUBLIC PERCEPTIONS OF COASTAL RESOURCES IN SOUTHERN
California State University, Channel Islands
California’s population of over 38 million reflects global trends towards a progressively coastal and urban populace. We are placing greater demands on increasingly burdened coastal ecosystems and need to identify where resource use conflicts might arise and where opportunities for compatible development can be enhanced. The annual California State University Channel Islands (CSUCI) Survey of Public Opinion of Coastal Resources has sampled public perceptions for eight years to examine opinion on a variety of environmental issues, and to provide a long‐term baseline to evaluate the efficacy of future management efforts. Southern California’s residents are aware of high profile coastal impacts like the Deepwater Horizon spill, however, many people are unfamiliar with the main entities engaged managing or mitigating these effects. Respondents reported concern for general ocean health and marine resources, ranking pollution as the primary threat to fisheries. People are less well informed about local coastal impacts and management interventions. Many Californians frequently enjoy recreation in coastal regions, however, relatively few people have visited the Channel Islands. Understanding the public’s perceptions and valuation of coastal resources is vital to achieve stakeholder-supported conservation efforts and to shaping effective policy.
Wynkoop, L.M.*, Jurgens, L.J., Gaylord, B.
IMPACT OF MUSSEL BED STRUCTURE ON DESICCATION OF TWO INTERTIDAL INVERTEBRATES
Bodega Marine Laboratory, University of California Davis
Mussel beds on rocky shores provide biogenic habitat for numerous intertidal invertebrates. It has been hypothesized that these structures create a refuge from potential predators and desiccation stress during low tide exposure. The latter issue in particular remains relatively unexplored. Here we quantified the degree of protection from desiccation stress that mussel bed structure affords for two common intertidal invertebrate species: the porcelain crab, Petrolisthes cinctipes, and the isopod, Cirolana harfordi. We transplanted individuals to locations inside the mussel bed, to the surface of the bed, and to the surface of bare rock. During 3-hour treatments conducted on multiple days during low tide, individuals on the surface of mussel beds and bare rock lost 19-54% of tissue water mass on days with high solar radiation. In contrast, individuals inside the mussel bed maintained nearly complete hydration under all weather conditions. These differences in desiccation had profound consequences for survival. Organisms inside the bed exhibited a 98% survival rate, while those on mussel bed surfaces and bare rock showed 38% and 29% survival, respectively. These findings reveal a crucial role for mussel beds in providing essential shelter to resident organisms, demonstrating an underappreciated mechanism of facilitation in this widespread system.
Zimmermann, S.A.*, Hillard, H., Edmunds, P.J.
ASSOCIATIONAL REFUGES ACROSS A STRESS GRADIENT ON THE NORTH SHORE OF MOOREA
California State University Northridge
In areas of high physical or biotic stress, one organism can ameliorate the implications of stress for adjacent organisms, thereby creating an associational refuge. In Moorea, French Polynesia, the reef crest (RC) is physically disturbed by waves but has few fish herbivores, while the back reef (BR) represents the reverse condition. We investigated two associations, one between Sargassum pacificum and Turbinaria ornata, and one between Sargassum and marine invertebrates and explored their functional bases across the RC-BR gradient. We hypothesized that the Sargassum/Turbinaria association was driven by the avoidance of herbivory created by chemically defended Turbinaria, whereas the Sargassum/invertebrate association was driven by the avoidance of wave action and predation in the BR. We tested for effects ofTurbinaria on Sargassum by removing Turbinaria and measuring Sargassum growth, and censused invertebrate abundance in Sargassum thalli at the RC and BR. Removal of Turbinaria had no effect onSargassum at the RC, but led to herbivory on Sargassum in the BR. The species richness and abundance of invertebrates were greater in Sargassum located in the BR compared to the RC. Together these results suggest that macroalgae can serve as refuges in modulating community structure in shallow back reef habitat.