Use the filters below to find awards made to CSU students by Program, Campus, or Year.
COAST Award Program
Society for the Advancemnet of Chicanos/Hispanics and Native Americans in Science, Salt Lake City, UT
Effects of low tide exposure on photosynthetic potential of the intertidal seaweed Silvetia compressa
Organisms in the rocky intertidal zone are exposed to marine and terrestrial stressors daily. Conditions during low-tide emersion can be particularly stressful for sessile organisms such as the seaweed Silvetia compressa. We hypothesized that exposure to high light or high temperature during emersion would decrease photosynthetic potential and inhibit recovery of S. compressa, and that these factors would have strong effects when combined, especially with repeated emersion. We conducted a two-day manipulative experiment with one ‘no low tide’ and four ‘experimental low tide’ treatments with combinations of two levels of temperature and light (high/low), maintaining fronds in high-tide conditions between exposures (n=10 S. compressa individuals). We measured maximum quantum yield (MQY) as an indicator of photosynthetic potential before and after each low tide and again following the final recovery period. Fronds exposed to high light showed greater declines in MQY during emersion than fronds exposed to low light. After one high tide recovery period, at the start of the second low tide, MQY in the ‘high light, high temperature low tide’ treatment was, on average, 77% of original levels, while MQY in all other treatments exceeded 85% of original levels. This negative effect was magnified after two successive low tides, suggesting that high temperature exacerbates the strong negative effects of high light levels on S. compressa, potentially by inhibiting repair pathways. Understanding the impact of low-tide exposure on ecologically significant species such as S. compressa is essential to enable us to predict the effect of climate change on intertidal systems.
Outcompeted or outbred? Localized extirpation of a native mussel via interspecific hybridization with a highly invasive congener
In southern California estuaries, non-native bay mussels, Mytilus galloprovincialis, are widely presumed to have replaced native bay mussels, Mytilus trossulus, but the regional extent and underlying processes influencing species replacement are poorly understand. Local aquaculture production of M. galloprovincialis provides the potential to enhance non-native spread and establishment, which may greatly influence native replacement and/or hybridization between the two species. Mytilus hybrid zones, whereby native and non-native species co-occur and interbreed are known from central California north to Vancouver Island, but are not reported in southern California. Using molecular genetics, our objectives are to characterize the species composition of mussel communities across salinity and elevation gradients in Orange County, California. Individual mussel samples were collected in Newport Bay (NPB), at three sites of varying salinity. We use species-specific genetic markers (Glu-5 and ITS) to identify pure-type individuals of both species, and hybrid individuals. Preliminary results to date show 100% of sampled mussels in NPB are M. galloprovincialis, suggesting complete replacement of native mussels with non-natives in NPB throughout the environmental gradients. Further sampling is ongoing, and this work will likely provide a better understanding of the processes responsible for native bay mussel extirpation, with possible implications for enhanced native mussel restoration.
Society for the Advancemnet of Chicanos/Hispanics and Native Americans in Science, Salt Lake City, UT
U.S. west coast estuaries support diverse communities that can be negatively impacted by changes in water quality. Atmospheric river (AR) events, long, narrow corridors of water vapor delivering heavy precipitation, can reduce the water quality in estuaries to levels lethal to oysters. For example, native Ostrea lurida densities declined significantly in San Francisco Bay following an extreme AR event that decreased salinities for a lethal duration (< 6 ppt for > 8 d). We focused our study on southern Californian estuaries that support native oysters, O. lurida, and non-native oysters, Crassostrea gigas. We hypothesized that AR events would produce extreme drops in salinity for lethal durations, as in San Francisco Bay, and O. lurida would show greater density declines than C. gigas. We measured density of both species in January and May 2017 at two sites each within Newport Bay (NB) and San Diego Bay (SD). Four AR events impacted NB and three impacted SD between December 2016 and May 2017. Salinity and pH dropped below tolerance levels for non-lethal durations in SD. Crassostrea gigas density declined significantly at three of four sites; however O. lurida showed no density change. Native O. lurida may be more acclimatized to local AR events than recently introduced C. gigas, or C. gigas declines may be due to another unknown factor. San Francisco Bay may be more susceptible to AR impacts on oysters by experiencing more extreme ARs and having a larger watershed; both can lead to more significant impacts on estuarine water quality.
Ocean Sciences Meeting, Portland, OR
Comparative analysis of planktonic productivity in Trinidad Bay and nearshore environments in Northern California during the 2017 upwelling season
Reproductive development of a deep-sea dragonfish (Stomias atriventer)
The black-belly dragonfish (Stomias atriventer) is a deep-sea species of Stomiiforme found in the eastern Pacific. Aspects of the black-belly dragonfish life history have been described including larval development, general morphology, biomechanics, and general behavior. However, little is known about the reproductive biology of this uncommonly observed deep sea fish. Our study explores the reproductive development of the black-belly dragonfish, specifically ovarian and testicular development. Dragonfish were collected via mid-water trawls onboard the R/V Yellowfin in southern California. We also examined museum specimens. The ovaries and testes were dissected, preserved in Bouin’s fixative, and histologically processed using paraffin wax. We had determined the diameter of ovarian follicles of various stages of development: primary ovarian follicles were 45.4 ± 19.1 µm, secondary ovarian follicles were 88.7 ± 21.4 µm, and tertiary ovarian follicles were 223.1 ± 27.9 µm. The testis contained spermatocytes that were 3.63 ± 0.18 µm, spermatids were 2.00 ± 0.16 µm, and mature sperm were 2.30 ± 0.53 µm in diameter. Our work will continue this summer with additional trawls, and we hope to determine the timing of reproduction in the black-belly dragonfish. Our research findings will increase our understanding of the seasonal development of deep sea fishes, an important trophic link to the surface waters of the ocean.
Geological Society of American Annual Meeting, Seattle, WA
Using high-resolution beach surveys to assess geomorphologic change within the Salinas sub-cell (Monterey Bay, CA) before and after the 2015/2016 El Niño
Littoral cells characterize California’s coast along with many other tectonically active coastal regions around the world. This study focuses on strategically chosen beaches of the Salinas sub-cell (part of the Southern Monterey Bay Littoral Cell) between the mouth of the Salinas River (sediment point source) and the head of the Monterey Submarine Canyon (sediment sink). Beach volume change is assessed at two beaches within the sub-cell during and after the 2015/2016 El Niño, combining high-resolution (< 10cm) surveying techniques such as terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV) areophotogrammetry. Molera, located approximately in the middle of the sub-cell, and Moss Landing, situated at the northern extent of the sub-cell just next to the head of the canyon, were surveyed approximately each month, and before and after major storm events. Volume changes of the subaerial beach were calculated by interpolating a triangular irregular network for each survey, subtracting the interpolated surface of each survey from the previous, and normalizing by area. Results reveal two main findings. (1) Moss Landing Beach experienced a substantial depositional event (+0.352 m3/m2) towards the end of summer 2016, followed by a series of erosional and depositional events throughout the winter. This variability does not reflect typical beach trends of winter erosion and summer accretion. (2) Extrapolating differentials across the area of the Salinas sub-cell suggests that short-term beach variability (days to a month) is on the same order of magnitude as previously published components of the yearly sediment budget for the Southern Monterey Bay Cell, such as beach erosion, dune erosion, and river discharge.
American Elasmobranch Society/Joint Meeting of Ichthyologists and Herpetologists, Austin, TX
Comparing persistent organic pollutants and trace metals in green sea turtles (Chelonia mydas) in two urbanized Southern California habitats
Two foraging aggregations of east Pacific green sea turtles (Chelonia mydas) inhabiting Long Beach (LB) and San Diego (SD), and are potentially exposed to persistent organic pollutants (POP) and trace metal contamination (TMC). Characterizing contaminant loads of these two turtle aggregations is important towards understanding the possible negative effects of anthropogenic contaminants. To calibrate POP and TMC methodology, turtles that have stranded in the LB and SD areas had their liver, heart, kidney, muscle, and fat tissue extracted and analyzed using GCMS and ICPMS. Preliminary results on stranded animals indicate undetectable (MDL 1 – 0.18 ng/g) to moderate amounts of POP contamination (123.00 – 9.51 ng/g wet mass total POPs in necropsy tissues) in both aggregations. Preliminary results indicate possible differences in TMC between animals in SD and LB. The stranded individual from LB had high cadmium contamination (221.49 μg/g wet mass) in kidney tissue compared with another stranded individual from SD (53.26 μg/g wet mass). Live green sea turtles from LB (n = 14 turtles) and SD (n = 23 turtles), were captured, measured and had blood and scute samples obtained for contaminant comparison. POP contamination will be determined using blood plasma with a modified soxhlet extraction via GCMS. TMC will be determined using red blood cells and scute samples with acid digestion and ICPMS. Blood, plasma and scute samples will be used to corroborate the preliminary results found in stranded samples, and to assess POP and TMC contamination loads, and differences between animals in both locations.
Society for Integrative and Comparative Biology, San Francisco, CA
Physiological performance: survival of an invasive mussel in a warming climate
As the climate warms, organisms endure rapid environmental changes and are susceptible to physiological damage that may force them to modify their thermal limits by either shifting their range distributions or being outcompeted by other species. Marine intertidal organisms, specifically, face unique challenges of oxygen limitation and aerial exposure, and it is up to us to understand how they might respond to such conditions and identify important biomarkers that can be used to recognize when an organism may be in jeopardy. Heart rate, is one physiological response, that is well-studied for investigating whole-organismal responses and can explain an organisms critical thermal limit. Furthermore, measurements of enzymatic activity of lactate dehydrogenase (LDH) can infer anaerobic metabolism and be indicative of stress. Thus, we hypothesize that the cardiac performance and subcellular activity of the invasive Mediterranean mussel (Mytilus galloprovincialis) will increase as temperature increases in both intertidal and subtidal populations. While exposing subtidal and intertidal mussels to varying temperatures (8-28 °C) at a ramping rate of 4 °C hr-1 we measured heart rate every hour and assessed LDH activity for each temperature treatment. For the submerged subtidal population of mussels, preliminary data suggests heart rate slowly increases as seawater temperature increase, while aerial exposed mussels reached a maximum rate at 12-16 °C. These measurements will begin to elucidate whether organisms have the capacity to deal with a changing climate and the physiological mechanisms that drive whole-organismal responses, while providing additional insight into the possible mechanisms that allow this non-native species to tolerate vastly different habitats and outcompete native species.
Society of Marine Mammalogy Biennial Conference, Halifax, Nova Scotia, Canada
Mapping vessel distribution in San Francisco Bay for improved spatial risk assessments and habitat suitability modeling of local marine mammal species
Interactions with vessels pose threats to marine mammals, and these threats are especially relevant in San Francisco Bay (SFB) where large ocean-going vessels coexist with a range of smaller vessel types. Within SFB, pinniped species are common, and cetacean species recently began entering, including harbor porpoise, bottlenose dolphin, and humpback whale. In an environment where human use overlaps marine mammal habitat, vessel distribution data is vital to evaluating risk assessments and habitat suitability for species, but little observation and analysis of traffic patterns have been done. To fill this data gap, we integrated Automatic Identification System (AIS) vessel identification data with location and speed data from a Doppler radar sensor continuously detecting and tracking vessels across a study area within SFB. Since AIS data transmission is only required for larger vessels, smaller vessels were identified through manual interpretation of logged photos from a high-definition camera linked to the radar sensor. Data were integrated in a geodatabase to produce vessel transects with vessel type and average speed attributes. These transects were overlaid with a cell grid so that each cell contained information on total unique transits and average speed traveled through it. Cells displayed a non-normal distribution in total vessel transits and average speed, suggesting that vessels do not utilize the study area evenly. A bivariate choropleth map coded to display both transit frequency and average speed confirmed that vessels occur most frequently and at the highest speeds in defined ferry tracks across the study area, with maximum speeds greater than 15 knots. Vessel speeds above 10 knots and vessel presence can lead to increased marine mammal mortality and habitat disruptions respectively.
Society for Integrative and Comparative Biology, San Francisco, CA
Effects of zinc oxide sunscreens on developing Strongylocentrotus purpuratus embryos
Increased releases of zinc oxide (ZnO) sunscreen ingredients into marine environments will accompany the growing popularity of physical sunscreens. Though zinc (Zn) is a necessary micronutrient in the ocean, greater than natural amounts of Zn enter marine environments by anthropogenic sources. The consequences of adding Zn to the ocean are not fully understood. We tested how physical factors affect the release of non-nano Zn and other sunscreen ingredients into seawater and effects of these ingredients on the development of California purple sea urchin, Strongylocentrotus purpuratus, embryos. We hypothesized that despite being labeled “reef or environment safe”, these sunscreens will have negative effects on the development of larval urchins because they release Zn2+, which may be internalized by the developing embryos. By simulating human Zn release during swimming using sunscreen on pig skin, we saw changes in Zn2+ release accompanying changes in water temperature, submersion duration and due to different formulations. To test toxicity, we exposed embryos to varying levels of ZnO sunscreens during development and observed the morphologies at the pluteus stage. Early exposure to ZnO sunscreens cause abnormalities typical of those observed in embryos exposed to Zn2+ during development. Additionally, we used fluorescent probes to quantify the levels of Zn2+ internalized, the amount of reactive oxygen species (ROS) produced, and the functional ability of the multidrug resistant transporters within the treated embryos. The combination of these assays will contribute to our understanding of how increased levels of internalized Zn2+ released by sunscreens can affect marine organisms.
Coastal and Estuarine Research Federation Conference, Providence, RI
Southern California wetland evolution in the Holocene: understanding the shift from oysters to salt marsh
Ostrea lurida (commonly the Olympic oyster) is the only oyster species native to the US Pacific coast. Although this species was once common throughout southern California, the past 200 years have seen a serious decline in abundance. Recent restorative efforts have targeted anthropogenic influences, but within the recent geologic record there is evidence of oyster decline that pre-dates human interference. Evidence of paleo-oyster communities has been observed as buried shell layers within modern salt marshes. Therefore, in order to improve management and restoration of this fishery, we must also understand the natural drivers that may adversely affect oysters in the region. In order to do this, we investigated the evolution of a southern California salt marsh that once supported an oyster reef community during the Late Holocene prior to the development of the marsh. Six cores were extracted from Los Penasquitos Lagoon and analyzed to (1) assess the ecology of the shells via shell identification and taphonomic analysis, (2) characterize the sediment using grain size and Loss-on- Ignition analyses, and (3) establish an age-depth relationship from radiocarbon analyses of shells and other material throughout the cores. The results suggest that the shells found were characteristic of an oyster reef community, however taphonomic analysis indicated that they may not have been in situ, but rather a locally reworked lag deposit. Stratigraphically, these shell layers mark the boundary for a shift in environments from an open-bay setting, to a salt marsh-tidal creek dominated estuary. The timing of this shift occurred in the late Holocene, and may have been driven by regional climate shifts resulting in improved sediment trapping in the lagoon. This study provides insight to the natural environmental factors that may have contributed to the decline in Ostrea lurida, and may aid future restorative efforts in southern California.
Ecological Society of America Annual Meeting, Portland, OR
Factors affecting the distribution of an invasive crab and its impacts on cordgrass restoration
Predators structure ecosystems by interacting with other trophic levels directly and indirectly. Indirect interactions can have large effects, yet are understudied in the context of restoration. We explored how predators and other environmental factors may impact crab distributions in the intertidal zone, and potential consequences of the resulting distributional shifts on restoration efforts of the native cordgrass (Spartina foliosa) in San Francisco Bay. Perceived threat from or direct consumption by subtidal predators at low tidal elevations may cause the non-native European green crab, Carcinus maenas, to seek refuge in high tidal elevations. These high elevations may include restored cordgrass habitat where crab foraging activity may cause damage. Crab distribution and predation on crabs were quantified using trapping and tethering experiments across tidal elevations and among different habitat types. We then evaluated the effects of crab activity within S. foliosa patches using a field enclosure experiment, caging newly planted cordgrass with and without crabs to assess crab impacts on cordgrass growth and survival. We found that C. maenas, which is rarely found at high tidal elevations elsewhere, has an atypical distribution in the Bay in which it is more common at high elevations. Caged treatments with green crabs had significantly fewer S. foliosa shoots at the end of a three-month period than plots without cages or crabs, suggesting that crab presence may hinder successful S. foliosa establishment. This work has important implications for management as interactions between multiple trophic levels can confound restoration efforts but are rarely considered in restoration settings. Illuminating the intricacies of species interactions will make future restoration attempts more efficacious and informed.
Society of Marine Mammalogy Biennial Conference, Halifax, Nova Scotia, Canada
Patterns of sea otter foraging activity and juvenile Dungeness crab habitat use in Elkhorn Slough
Recovery of top predators can improve ecosystem functioning but may also lead to conflicts as predators and humans compete for common resources. The reestablishment of sea otters in Elkhorn Slough has been shown to benefit seagrass indirectly through otter consumption of rock crab. Although we have information on how otters affect rock crab populations from multiple systems, there is little information on how otters may impact economically important Dungeness crab that use estuaries as nursery grounds. To examine the relationship between otter predation and juvenile Dungeness crab, we characterized spatial variation in foraging otter density and diet via biweekly distribution surveys and observational data on otter foraging. We also measured abundance and size of crab by monitoring crab caught in standardized traps. Initial analyses suggest no clear relationship between Dungeness crab abundance and sea otter density within Elkhorn Slough, although few crabs larger than the average size consumed by otters were found in Elkhorn Slough in 2016. Our results suggest that juvenile crab are either being consumed by otters before reaching maturity in Elkhorn Slough or crab are leaving Elkhorn Slough at an earlier life history stage than previously documented for other estuaries supporting juvenile Dungeness crab nurseries. Understanding the potential influence of otters on Dungeness crab is of particular importance for California fisheries as sea otters continue their range expansion northward into other estuaries that act as important nurseries for Dungeness crab.
American Fisheries Society Annual Meeting, Tampa, FL
Insulin-like growth factor I (IGF-I) as a physiological biomarker for growth rate in juvenile Sebastes rockfishes
Current methods for quantifying the growth rates of wild fish require terminal sampling (otolith analysis), time consuming tagging (mark-recapture), or may have limited value as indicators of somatic growth (RNA:DNA ratios). The development of novel, non-lethal methods for quantifying growth rates is therefore needed. Blood concentrations of the hormone insulin-like growth factor-I (IGF-I) regulate growth and metabolism in fish. Here, we tested whether plasma IGF-I concentrations could be used as a tractable indicator of somatic growth and nutritional status in Sebastes rockfishes, a genus important to commercial and recreational fisheries on the Pacific coast of N. America. We collected juvenile olive rockfish (S. serranoides) from central California, and reared them under food rations of 1% or 4% wet mass per day to experimentally generate growth variation. Rockfish raised at 4% rations exhibited higher growth rates and elevated plasma total IGF-I concentrations compared to fish under 1% rations, and individual variation in IGF-I was positively related with individual growth rate. Rockfish fed 1% rations also expressed elevated liver mRNAs for IGF-I and IGF binding proteins, indicating that ration quantities alter IGF hormone signaling at several levels. These findings support IGF-I hormone variation as a physiological correlate of growth rate in rockfishes.
Red de Genética para la Conservación - XII Taller de Genética para la Conservación, Sucre, Bolivia
Assessing introductions and morphology of a globally invasive marine invertebrate
Botyllid tunicates are cryptic; the external morphology of adults is insufficient when identifying the species. Thus, issues arise in denoting species purely from morphology or genetics. Three invasive species that are seen globally, including California are Botrylloides violaceous, Botryllus schlosseri, and a third species variously named, Botrylloides diegense and Botrylloides leachii. Assessing the genetic diversity of botryllid species can yield valuable insights into population connectivity and aid understanding of the introduction vectors and dispersal potential of this marine invader. Taking a closer look at the morphological differences at larval and early development stages allows for a better understanding of key differences between species. In accomplishing this, live specimens will be collected from various locations of the Pacific coast of North America. Colonies will be kept alive in the lab to culture and collect larvae from, which will then be microscopically assessed. Tissue samples will be taken from each colony and preserved in 95% ethanol for later DNA extraction and a multiple gene comparison. Sanger sequencing of the mitochondrial cytochrome oxidase I (COI) locus will be used for further species identification and phylogeographic understanding, and of the nuclear adenine nucleotide transporter (ANT) locus to further define the phylogeography. We expect Botrylloides diegensis and Botrylloides leachii will result as separate lineages due to single or multiple character changes within the Botrylloides lineage. Also, that the limited reproductive mechanisms of the species will result in low and similar levels of genetic diversity across populations. With potential dispersal vectors identified and proper identification of the invasive botryllid species, this study can better direct efforts towards protecting ecosystem functions in areas most populated and affected by this marine pest.
Effects of maternal age on offspring behavior and growth efficiency in northern elephant seals (Mirounga angustirostris)
Offspring of capital breeders, such as the northern elephant seal (Mirounga angustirostris), are nursed exclusively from maternal body reserves. Previous investigations have shown that milk energy delivery rate in northern elephant seals increases with the size and age of the female. Milk energy intake and offspring storage data (n=47) suggests impacts of maternal age on growth efficiency that are independent of rates of energy delivery. To better understand the mechanisms underlying this effect of maternal age, behavioral data were collected from pups of 46 known-age females, from parturition to weaning, across six years and three different sites along the Central California Coast, representing 3,954 seal-hours of observation. Pup behaviors were divided into five mutually exclusive categories that reflected pup energetics (e.g. locomotion vs. suckling). Maternal age had a significant effect on pup behavior. Pups of older females spent more time suckling and resting, while pups of younger females spent more time vocalizing, locomoting, or distant from their mother. Pup behavior also varied strongly with days post-partum and time of day. The magnitude of these effects varied between rookeries, suggesting influences of harem topography and environmental features on pup behavior. Together these finding suggest direct impacts of maternal breeding experience on pup behavior and growth efficiency.
Long term trends in baleen whale observations near the Farallon Islands, CA
We examined temporal trends in arrival time, peak abundance, and departure time of blue (Balaenoptera musculus) and humpback whales (Megaptera novaeangliae) near the Farallon Islands, Central California. We used daily counts of whales collected from Southeast Farallon Island (SEFI; 37°34’N, 123°00’W) from 1987 to 2015. We hypothesized that the timing of whale migration responds to basin scale oceanographic patterns. Preliminary analysis of the data show that blue and humpback whales are most commonly seen near the Farallones during the fall and summer months. Humpbacks were most commonly observed from July to November until the early 2000s. In the last 5 to 7 years humpbacks have been observed in high numbers as early as April, and were present year round in 2014-2015. Blue whales showed a similar pattern. Through the majority of the study they were most commonly observed from August to October, but have been observed as early as January in the last eight years. This work is important for officials that manage the Marine Sanctuaries, commercial shipping lanes, and fisheries that are in the Gulf of the Farallones ecosystem. If whales are utilizing the area at different times of the year, then seasonal management practices must be adjusted as well to accommodate the new migration times. This analysis will be important for the future conservation of both blue and humpback whales that visit and inhabit the waters near the Farallon Islands.
Collaborative research methods for surveying fish communities associated with nearshore rock reefs in Northern California Marine Protected Areas
Rocky reefs are iconic features of the California coast that support both recreational and commercial fisheries and provide habitat for a rich diversity of fishes. Using methods developed by the California Collaborative Fisheries Research program, we conducted hook-and- line surveys in partner with commercial passenger fishing vessel (CPFV) captains and volunteer fishers to characterize baseline status of nearshore rocky reef fish assemblages in four pairs of marine protected areas and reference areas along the coast of Northern California. The project sampled 4,248 individuals of 22 species, including 14 species of Rockfish (Sebastes spp.). Catch composition was dominated by Black Rockfish (S. melanops, 39%), Blue Rockfish (S. mystinus, 19%) and Lingcod (Ophidion elongatus, 15%) across all sites. The sampling effort was successful, but hampered by the remote nature of some ports and sites, frequent unfavorable sea conditions, mechanical problems, and scheduling around the captain’s regular business -- challenges that led to the cancellation of 12 of the first 15 sampling trips. Though requiring greater coordination among the collaborators, scheduling trips within the 5 day coastal waters forecast window resulted in a far lower cancellation rate, and benefited captains by allowing them to fill days when no other charter was booked. The project engaged 40 volunteer anglers and 12 professional crew.
Inferred spawning activity of three exploited gamefishes on a large artificial reef
Kelp bass (Paralabrax clathratus), barred sand bass (P. nebulifer) and California sheephead (Semicossyphus pulcher) are three important recreational gamefish species in southern California and as such contribute significantly to the local economy. To restore depleted populations, artificial reefs have been used with the assumption that the new habitat will increase fish productivity over time. Here, we describe the fine-scale area use at a range of temporal scales, and presumed spawning related activity inferred from passive acoustic telemetry methods on the largest artificial reef in the United States. Degree of site fidelity to the artificial reef varied considerably across species over a two year monitoring period, with sheephead exhibiting the highest site fidelity. On average, kelp bass had the largest home ranges (0.33 ± 0.13 km2 ; 95% kernel utilization distribution), but the amount of area used was similar among species. Area use was also similar to previous findings using comparable methodology. Tagged kelp bass exhibited two different activity patterns during spawning months described as “transient” and “sedentary”, and ~40% of tagged barred sand bass displayed seasonal migratory behavior. Male California sheephead were significantly more active among seasons than females; however, both showed increased activity patterns in summer months. Results of this study indicate that artificial reefs can provide suitable habitat to support depleted gamefish species, although some may benefit more than others. Additionally, assumed spawning related activity implies artificial reefs can be worthwhile management tools to mitigate depleted coastal marine fishery populations.
Behavioral effects of angling and handling stress on kelp bass, Paralabrax clathratus, in southern California
Catch and release is a common regulatory strategy for many gamefish species, including kelp bass (Paralabrax clathratus), yet effects of capture-related stresses on fish physiology and behavior are species-specific and remain largely unknown. Quantifying these impacts, and identifying best practices, will aid in managing the economically and ecologically valuable kelp bass fishery in southern California. Fish movement and activity following catch and release were evaluated in the Catalina Island Marine Life Reserve using a VRAP receiver array and acoustic accelerometers (Vemco Ltd, USA; V9A). To evaluate effects of stress on behavior fish were caught on hook and line, force-fed a transmitter, and released; control fish were fed squid with a hidden transmitter underwater by divers. All fish were tracked until tag was regurgitated (range 2- 8 d) and recovered. Area (m2) of the core range (50% KUD) and home range (90% KUD) were significantly reduced in fish caught and released for the first 6 hrs at liberty, but was similar to that of control fish by 18-24 hrs post- release. Kelp bass exhibit diel behavioral patterns with highest activity (acceleration, m/s2) during crepuscular periods. Caught and released fish exhibited fewer episodes of high activity (associated with normal foraging, predator avoidance, and reproductive activities) than control fish for 24 hr post-release, but resumed normal activity within 48 hr. Capture and handling stresses may result in some behavioral impacts (reduced area use and activity) but individuals appear to rapidly recovery within 24 hrs.
Diel movements and fine-scale activity patterns across heterogeneous thermal environments of the CA horn shark, Heterodontus francisci
Because water temperature influences internal body temperatures of ectothermic sharks, it is considered the key environmental variable to directly influence their physiology (e.g., metabolism) and behavior (e.g., movement patterns, feeding rates). This project uses active acoustic telemetry and accelerometer data loggers (ADLs) to quantify diel movements and fine-scale activity rates of horn sharks (Heterodontus francisci) as they move through a heterogeneous thermal environment. At Catalina Island, nine horn sharks (1.8 – 3.5 kg) were fitted with custom tag packages that include an acoustic transmitter (Vemco, V9-6L) and an ADL which records 3D body acceleration, depth, and temperature. Each shark was continuously tracked for 24 hrs. After being tagged, individuals tended to rest in shallower, warmer water during the day. Diel movement spaces ranged from 1,140 m 2 to 44,440 m2 of space, with 67% of their movement activities occurring at night. Horn sharks spent approximately 65% of daytime hours resting, whereas only 32% of nighttime hours were spent resting. During the nighttime activity periods, sharks experience up to a 10°C difference while traversing deeper (>30 m habitat). Sharks were found being active in temperatures from 9°C to 24°C. Differences by size and sex were additionally examined to determine what mechanisms influence horn shark activity. Quantifying horn shark movements and activity across heterogenous environments will allow us to quantify their energetic landscape and to predict how changing ocean temperatures may affect the distribution and behavior of this kelp forest associated species.
Effects of temperature and mass on the metabolic rate of a sedentary reed fish, the bluebanded goby (Lythrypnus dalli)
As climate continues to change, many marine species will experience both an increase in average temperature and more extreme diel and seasonal fluctuations. Understanding how these variations in ocean temperature affect processes such as metabolism and energy consumption is important for many species, and particularly so for sedentary species that cannot make large-scale movements in response to changes in environmental conditions. We examined how metabolic rates and energetic demands responded to temperature in a temperate reef fish, the bluebanded goby (Lythrypnus dalli). Using respirometry, we estimated resting oxygen consumption (VO2) and calculated metabolic rates (MR) at three different temperatures (13°C, 16°C, and 20°C) for 42 L. dalli individuals of varying sizes. As predicted, VO2 and MR increased significantly with temperature and mass, but the rate of temperature-dependent increase in metabolism indicated a very high degree of thermal sensitivity for L. dalli (Q10 value for VO2 was 5.53 across the range of experimental temperatures). The mass-scaling coefficient (b) was estimated to be 0.827 and aligned closely with other benthic species. Thermal fluctuations likely play a significant role in the ecology of these gobies and continued increases in seawater temperature will either necessitate an increase in foraging and consumption or drive costly trade-offs between metabolism and processes such as growth and reproduction.
A risk assessment analysis of San Francisco Bay for southern sea otters (Enhydra lutris nereis)
Historically abundant along the North Pacific Coast, southern sea otters are currently restricted to a portion of the central California coast and the population is straining under increasingly limited resource availability. Despite recent, localized increases in population numbers, sea otters must expand into new resource-abundant territories in order for larger and sustained population growth to occur. Restoring sea otters into ecosystems in which they have largely been absent for centuries presents additional opportunities for the recovery of degraded ecosystems through top predator mediated trophic interactions, but it comes with serious challenges, as well. San Francisco Bay, the largest California estuary, lies outside the current extent of the sea otter range and is being considered as a site for a sea otter reintroduction attempt. Despite a historic abundance in San Francisco Bay, it is unknown whether a sea otter population could thrive in this now highly urbanized estuary. A comprehensive assessment of the various threats sea otters would face in this new environment is necessary before reintroducing sea otters to this area in order to understand the challenges and costs that could hinder the success of this action. Using expert opinion and a Delphi technique, we identified and ranked 4 risk factors relevant for San Francisco Bay that could be hazardous to sea otters and their estuarine habitats: vessel traffic, contaminants, terrestrial runoff, and fisheries activities. These results will be combined with a predictive species distribution model, using habitat and prey covariates, to determine where areas of high risk-exposure and high likelihood of sea otter presence may overlap. This spatially explicit risk assessment profile will provide critical information to managers about the potential threats sea otters will face as they reoccupy their historic home ranges so that appropriate mitigation measures can be taken.
Ecological Society of America Annual Meeting, Portland, OR
Warming and inundation timing effects on California vernal pool communities
Models indicate that increases in air and water temperature will alter the structure and function of ecosystems at both global and local scales. Communities are structured by a variety of abiotic (e.g., temperature) and biotic (e.g., competition) factors. In freshwater ecosystems, hydrologic characteristics (e.g., hydroperiod, magnitude, & timing) are central factors that influence community composition and abundance. Although warming experiments are not uncommon among research on freshwater ecosystems, little information is known on how warming will affect temporary aquatic systems that are dependent on annual temperature and hydroregime intervals. The purpose of this study is to examine the aquatic community composition of temporary ponds in response to increases in water temperature and a shift in the timing of inundation. To accomplish this, I manipulated water temperature (warm, ambient) and inundation timing (early, late). Each treatment was replicated 5 times. Mesocosms lined with 2.0 cm of California vernal pool soil were established on the CSU, Sacramento campus on January 15, 2017. This study identified the potential responses of vernal pool communities to increased temperatures and unstable precipitation regimes resulting from climate change. Warming and inundation timing independently affected species densities, diversity, and community composition. Warming increased the abundance of small-bodied zooplankton species, while also increasing mosquito densities. This shift towards smaller organisms highlights the importance of metabolism as an underlying process that structures aquatic communities.
California Native Plant Society Conservation Conference, Los Angeles, CA
Effects of manual and mechanical Ammophila arenaria (Poaceae) removal techniques on coastal dune plant communities and dune morphology
European beach grass (Ammophila arenaria [Poaceae]) invades and stabilizes the foredune in coastal sand dune ecosystems and can cause a decline in native species. The objective of this study is to examine the effects of manual and mechanical removal techniques of A. arenaria on sand dune morphology, and vegetative cover and species composition over time. Study sites were located within three California State Parks: Little River State Beach, Gold Bluffs Beach, and Tolowa Dunes State Park. Two removal treatments were utilized at these sites: mechanical, which utilizes bulldozers to bury A. arenaria; and manual, digging the plant up with shovels. Vegetation cover and species composition was measured in 25 m2 plots at each site (n=69). Dune morphology was measured at restored and unrestored sites using a Real Time Kinematic Global Positioning System device to measure the elevation of the dunes in transects at each site for each removal technique. An Unmanned Aerial Vehicle (UAV) was also utilized to measure dune elevation by taking high resolution photographs of the dunes in the treatment and control sites that were then converted to topographic data with Structure for Motion software. Moreover, height measurements were taken with a tape measure at established waypoints along each transect. These three techniques were compared to determine which is the most accurate and effective for measuring elevation. Results will provide insight into the long-term recovery of native species and will compare the effectiveness of mechanical versus manual removal in restoring natural sand movement.
American Elasmobranch Society/Joint Meeting of Ichthyologists and Herpetologists, Austin, TX
How the devil ray got its horns: the molecular evolution and development of the Myliobatidae
Batoids (skates and rays) are a diverse clade of cartilaginous fishes comprising over 550 recognized species. Sometimes called “flat sharks”, their dorso-ventrally flattened bodies and anteriorly elongated pectoral fins distinguish batoids from sharks, while variations on this body plan differentiate batoid taxa from one another. Most batoids live a benthic lifestyle and generally exhibit round flexible pectoral fins that are used for both feeding and locomotion. In contrast, pelagic batoids of the family Myliobatidae have evolved diamond-shaped pectoral fins that are used solely for locomotion and an extra pair of anterior fins called cephalic lobes, which are used for feeding. Though the functional benefits associated with the unique myliobatid fin morphologies have been documented, little is known about the underlying genetic mechanisms associated with their evolution and development. Using RNA-Sequencing, we have examined gene expression among eight distinct fin domains in the cownose ray (Rhinoptera bonasus), a derived pelagic myliobatid, at two different stages of early development. Our comparative transcriptomics approach has revealed both ancestral and novel gene expression pathways in the fins of cownose ray embryos, suggesting that the myliobatid body plan evolved by layering novel gene expression pathways on top of those that give rise to the ancestral batoid body plan.
Linking high-resolution contaminant screening to endocrine disruption in marine mammals
Environmental pollutants have previously been associated with changes in endocrine health in cetaceans. Previous attempts to characterize changes in serum hormones with environmental contaminants have largely been limited to dead or captive individuals due to logistical constraints. Additionally, although many contaminant studies typically target a limited number of halogenated organic compounds (HOCs), they do not investigate minimally characterized or unknown, potentially toxic contaminants of emerging concern (CECs), missing the detection of CECs in situ before they pose risk to wildlife or human health. Here, we use blubber hormone quantification, a validated molecular method developed to assess reproductive health in free-ranging cetaceans, to evaluate endocrine effects of contaminants. We also employ a novel technique that uses comprehensive two-dimensional gas chromatography coupled to time-of- flight mass spectrometry (GC×GC/TOF-MS) to detect legacy contaminants and CECs with a non-targeted analytical approach. We integrated these two analytical methods for the first time to validate this approach to identify potential endocrine disrupting HOCs in 16 male short-beaked common dolphins (Delphinus delphis) from the Southern California Bight (SCB). We detected 167 compounds, including 81 anthropogenic compounds, 49 compounds of unknown origin, and 37 from natural sources. We also found evidence of bioaccumulation and endocrine disruption in mature individuals. An identified cluster of known toxic and unknown HOCs was negatively correlated with blubber testosterone when corrected for differences in age and gonad weight. We conclude that elevated anthropogenic contaminant loads contribute to impaired testosterone production in male D. delphis in the wild. The application of this novel, paired approach to marine mammal contaminant risk-assessment allows for inference of biological consequence following accumulation of HOCs, the identification of new endocrine disrupting HOCs, and prioritization of compounds for future ecotoxicological research in marine mammals.
Changes in the proteome of northern elephant seal pups during the postweaning fast
Northern elephant seals are subjected to prolonged periods of fasting of up to three months depending on age and sex. In pups, this fast occurs during the postweaning fast, an 8 to 12-week period during which they rely solely on energy reserves gained during nursing for their caloric requirements and water supply. The postweaning fast is the first of many, and it helps the pup to develop into a diving marine mammal that is capable of foraging at sea. The purpose of this study was to understand the fasting and diving-induced developmental changes of pups during this critical transition from a terrestrial to aquatic lifestyle. To investigate this, we collected skeletal muscle and adipose tissue from pups early and late in the developmental fast. We analyzed the samples with mass-spectrometry- based proteomics using 2D gel electrophoresis. We found significant shifts in metabolic proteins that suggest a decrease in amino acid metabolism and urine production during the postweaning fast, and an increase in alternative metabolic pathways (such as the pentose phosphate pathway) that support cell proliferation. We also found increases in cytoskeletal, skeletal muscle, and oxygen-binding proteins that aid in the development of the diving ability in pups. There were also shifts in the abundance of acute phase proteins that support an increased immune response, possibly due to a higher risk of inflammation from microbial infection. Lastly, there was a shift in antioxidants that control the production of reactive oxygen species. These results provide key physiological information regarding pup development throughout ontogeny.
Change in an estuarine phytoplankton community after removal of commercial oyster mariculture.
Oysters, clams and other suspension feeders in natural ecosystems have the capacity to reduce phytoplankton abundance and increase water clarity in estuaries, lagoons and lakes. However, the effects of oyster mariculture on water quality, especially the abundance and composition of phytoplankton, remains an unanswered question. At the termination of a long-term lease on National Park Service property on Drakes Estero (located in Point Reyes National Seashore, CA), Drakes Bay Oyster company was required to close operations and remove all oysters from the estuary, in keeping with the Estero’s federal wilderness area designation. This provided an unusual opportunity to compare water quality before and after oyster mariculture. With Sea Grant funding, changes in water quality and phytoplankton community were assessed, comparing results to a prior study done when oyster mariculture was present to test the hypothesis that algal blooms might occur more frequently. Three phytoplankton bloom events were detected; in October 2016 throughout the Estero, and at the seaward locations in June and July 2017. Phytoplankton were enumerated for each event and compared to historic published data from 2010-2011 when the oyster company was in operation. In October 2016, the total algal biomass was ~70% dinoflagellates, while seaward spring blooms in 2017 were dominated by chain-forming centric diatoms. Removal of oysters did not impact bloom occurrence or characteristics of bloom composition. Prior (2010-2011) and post (2016-2017) oyster removal bloom characteristics were similar with fall dinoflagellate blooms and spring centric diatom blooms. However, post removal bloom sample cell counts had greater proportions (94-97%) of small-celled flagellates compared to pre-removal., suggesting oysters may have filtered out small flagellates. Results of this study may inform management choices regarding the relative ecosystem value of coastal aquaculture versus wilderness restoration.
Society for Integrative and Comparative Biology, San Francisco, CA
Do larval settlement preferences determine local distribution patterns of the serpulid annelid Ficopomatus enigmaticus?
The serpulid Ficopomatus enigmaticus, likely a native of Australia, has established populations on every continent except Antarctica. Invasive populations of this species often show two striking distributional patterns: individuals are found in dense aggregations (reefs), in low salinity habitats. A process that may be important in establishing both patterns is the expression of settlement preferences by larvae. To test the hypothesis that larvae of F. enigmaticus settle preferentially on conspecific adults, contributing to reef formation, we conducted two experiments. First, larvae were exposed to biofilmed tubes of conspecific adults or to biofilmed shell or tube of two other species. Settlement was significantly higher on conspecific tubes compared to other substrates. Second, larvae were exposed to various substrates in clean seawater or in seawater in which adult worms had been held. Adult effluent had no effect on larval settlement. Larval responses to cues associated with the tubes of conspecifics may thus be one factor important in reef formation. To test the hypothesis that larvae settle most readily in low salinities, we examined larval settlement in response to adult tubes or IBMX (a pharmacological inducer) in seawater adjusted to 5, 20, or 34 psu. Settlement was high at all salinities tested in both adult tube and IBMX treatments, suggesting that larval responses to salinity are not important in determining the local distribution of F. enigmaticus. Future work should test alternative hypotheses to explain the observed distribution of adults with respect to salinity, for example that juveniles and adults are excluded from full-strength seawater habitats by competition from fully marine species.
Does temperature affect aggressive behavior in aggregating anemones?
The mechanisms leading to competitive dominance of the alga, Desmarestia ligulata, following storm-related disturbances
Factors affecting size of benthic macroinvertebrates and degree of fish associations in Cordell Bank National Marine Sanctuary
Regulation of a lost inducible heat shock response in Antarctic fishes
Geographic and habitat-based variation in demography and life-history of Canary Rockfish (Sebastes pinniger) along the U.S. West Coast
Spawning related movements of giant sea bass (Stereolepis gigas) at Catalina Island, California
Modeling habitat accessibility for seabirds in dynamic windscapes
Implications of the Water-Energy-Food Nexus on coastal groundwater management and policy in Pajaro Valley, CA
Evaluating the role of low impact development for sustainable groundwater resources in costal California
Freshwater and marine survival of Coho salmon (Oncorhynchus kisutch) as a function of juvenile life history
Modeling climate change impacts on flooding and community vulnerability, Novato, CA
Optimizing temperature in green abalone culture methods to increase resilience in the California aquaculture industry and restore wild populations
Assessing the effects of Southern sea otter predation on Dungeness crab in California estuaries
Effects of beach structure and sediment characterization on meiofaunal diversity along the California coast
Comparison of multiple antibiotic resistance in coliforms at Southern California beaches with differing wave action during dry and wet weather
Under pressure: the physiological response of Mytilus edulis to multiple stressors
Impacts of paired Olympia oyster (Ostrea lurida) and eelgrass (Zostera marina) restoration on fish and invertebrate communities in Newport Bay, California
Impacts on ecosystem productivity due to dam diversions on the Upper Mainstem Eel River
Examining effects of maternal foraging strategy on wean mass of northern elephant seals (Mirounga angustirostris) using stable isotopes analysis
Exploring values and conflict surrounding human-seal interactions in California and Hawaii