Research opportunities are increasingly offered to undergraduate students and recent graduates to help them understand marine and aquatic sciences and offer them an opportunity to consider career options. This session will provide a venue for undergraduate and post- baccalaureate research in a general session that highlights the wide variety of student research. Presenting at meetings is an opportunity for students to engage with the science community and for interested faculty to discuss potential projects. This session is designed for students who are presenting for the first time at a scientific meeting and for mentors looking for possible graduate students. Students are not limited to this session, and we encourage any student who wishes to submit an abstract to a specialized science session in the subject of their research to consider that option as well.
Lead Organizer: David Fields, Bigelow Labs for Ocean Sciences (dfields@bigelow.org)
Co-organizers:
Lisa ROM, NSF (elrom@nsf.gov)
Hayley Schiebel, Suffolk University (hschiebel@suffolk.edu)
Presentations
06:00 PM
Viscosity drives feeding behavior of E. norvegica (8789)
Primary Presenter: Timothy Buckley, University of Connecticut/Bigelow Laboratory For Ocean Sciences (timothy.buckley@uconn.edu)
Temperature has been shown to affect the swimming performance of copepods, and this is typically attributed to changes in physiology, such as metabolic rate. However, the physical properties of water are also affected by temperature changes, particularly the kinematic viscosity of water is substantially higher at lower temperatures. In this study, we investigated the extent to which the thermal dependence of copepod prey capture reflects changes in the physical properties of water independent of physiological changes. Copepods are a key link in the marine food web, bringing energy from primary producers to higher trophic levels. While much is known about herbivorous copepods, less is understood about the role of carnivorous copepods in marine ecosystems. Euchaeta norvegica, a marine carnivorous copepod, was used to conduct feeding experiments that separate the effect of temperature and viscosity on ingestion rate. Based on data from functional response curves, we ran experiments in 4L jars at a concentration of 9 prey/L(Acartia hudsonica). Ingestion rates were measured at temperatures ranging from 4C-16C. Viscosity trials were conducted at 12C and mimicked viscosities from 12C-0C by adding a high weight molecular polymer (polyvinylpyrrolidone; MW 360 kD). Our study found E. norvegica eat less prey at lower temperatures and higher viscosities. When viscosity was altered independent of temperature, 64%-73% of the change in the ingestion rate was due to viscosity. These results support the hypothesis that viscosity has a greater impact on the ingestion rate than temperature.
06:00 PM
CAN ZOOPLANKTON UTILIZE DISSOLVED AMINO ACIDS AS A NUTRIENT SOURCE? (8823)
Primary Presenter: David Gonzalez, California State University Dominguez Hills (dgonzalez386@toromail.csudh.edu)
In the marine food web, crustaceans are best known for their role as consumers of primary producers and other organisms; however, there is growing evidence that some species are capable of dissolved nutrient uptake in the form of amino acids. This leads us to hypothesize that copepods, the most abundant and widespread marine crustacean, may also be able to actively utilize amino acids from their environment via absorption or other uptake pathways. Here we explore how zooplankton contribute to marine biogeochemical cycles by acting as both a source, returning nutrients to the environment via excretion, and as a sink, via amino acid uptake, for dissolved nutrients. In parallel but separate 24-hour incubations, we measured 1) the amount of ammonium excreted and 2) the absorption of amino acids by Calanus sp. collected from the Gulf of Maine. To test copepod absorption of amino acids, Calanus sp. were collected and incubated in seawater with dual isotopically-labeled (15N and 13C) amino acids; then their level of isotopic enrichment was analyzed and compared to unexposed (control) Calanus sp. incubated over the same 24 hour period. Our results showed that ammonium excretion ranged broadly from 0.03 to 0.13µmols per individual per 24 hours. We also discovered that Calanus sp. are capable of absorbing amino acids and that the carbon to nitrogen ratio of the absorbed substrate (1.1:1) was lower than the initial substrate (4:1), indicating preferential uptake of nitrogen. This establishes a previously unrecognized source of nutrients for copepod metabolism.
06:00 PM
Seasonal Variations of Dissolved Organic Matter Bioreactivity in New Jersey Coastal Waters (8860)
Primary Presenter: McKenna Fernandini, Kean University (fernanmc@kean.edu)
Located near urbanized areas, New Jersey coastal waters connect human and natural biological activities which impact the level of dissolved organic matter (DOM) and its bioreactivity in the water. New Jersey Barnegat Bay is a brackish water body that receives runoff of both inorganic and organic matter from surrounding towns. The increasing amount of human-induced inorganic nutrients found in coastal waters trigger algal blooms, which affect DOM dynamics and bioreactivity at vary times during the year. Amino acids can be used as an indicator for DOM bioreactivity in water. This research was conducted to determine the levels and composition of amino acids in the Barnegat Bay over two seasons (spring-summer versus winter). Samples were taken at various times throughout the year from surface water at two locations along the bay. Hydrochloric acid was used to perform hydrolysis of water and thereafter the hydrolysate samples were run through high performance liquid chromatography (HPLC). The concentrations of amino acids and amino acid % in bulk dissolved organic carbon were higher during the spring-summer months versus the winter months, corresponding to algal blooms occurring during the spring-summer and suggesting that there are more sources of bioreactive DOM in the warmer months. Amino acid compositions also revealed less degraded DOM in the spring-summer time, indicating different sources of DOM between seasons. Understanding DOM sources and bioreactivity is crucial to decipher the carbon cycle and its relationship to anthropogenic and in situ microbial activities.
06:00 PM
Investigating Water Quality and Algae-Bacteria Interaction in NJ Coastal Long-Term Monitoring Sites (9069)
Primary Presenter: derek melendez, kean university (derekmelendez173@gmail.com)
Derek J. Melendez, Erin Kraus, McKenna R. Fernandini, Shuting Liu Department of Environmental & Sustainability Sciences, Kean University, Union, NJ 07083 The algae and bacteria interactions in NJ coastal waters impact water quality. Both organisms influence the amount of organic carbon, nutrients, and other essentials that the ocean contains. In the summer, algal blooms usually occur in NJ coastal waters while in the winter there is less algae biomass due to lower temperature. In this study, our main question was to find out what were the environmental factors that affect the water quality and how algal and bacteria interactions played their part in that. We collected surface water in two long-monitoring stations in Barnegat Bay, NJ over the spring-summer of 2023 and winter of 2024 and analyzed inorganic nutrients, chlorophyll, dissolved organic carbon/nitrogen, and bacteria. Temperature and dissolved oxygen have an inverse relationship throughout the time. Chlorophyll concentrations were significantly higher at one station in the spring-summer than in the winter, but not at the other. Significantly lower concentrations of nitrate+nitrite and phosphate in the spring-summer suggest algal took up these nutrients. Dissolved organic carbon concentrations were not significantly different over the season, however, dissolved organic nitrogen was significantly higher in spring-summer, corresponding to higher bacterial abundance at the same time and indicating nitrogen-rich dissolved organic matter supported bacterial growth. We concluded that investigating the interaction among environmental factors is a must to understand the conditions of coastal waters and that they are inter-correlated with each other in our coastal waters.
06:00 PM
Evaluating the Impact of Artificial Light at Night on Juvenile Salmonid Predation Risk in the Lake Washington Ship Canal (9074)
Primary Presenter: Luke Valleli, University of Maine (lvalleli13@gmail.com)
The Lake Washington Ship Canal is the only outmigration route to the Puget Sound, making it key to the conservation of native anadromous salmonids. Artificial Light at Night (ALAN) fosters perpetual twilight conditions, increasing predation opportunity for visual foragers effective in low-light conditions. To explore conservation strategies related to reducing ALAN, the Fremont Bridge was chosen for a case study as it is impacted by skyglow, street lights, and an underbridge art installation. Downwelling spectral irradiance was sampled using the Biospherical Instruments C-OPS. Daytime profiles were collected to analyze light attenuation. Nighttime surface light levels were sampled with the art lights on and off. These data were then used to model nighttime spectral profiles. Predator search volumes were modeled using a visual foraging model parameterized for coastal cutthroat trout, a key predator in the system. The impact of the art lighting is not statistically significant on overall light levels, other than directly under the bridge. Distant enough from the bridge that the spectral fingerprint of the art lighting is not visible, light levels are similar to or brighter than those under the bridge. Spatially modeled predator search volume shows that under-bridge predation risk only slightly exceeds the levels seen beyond the influence of bridge-related ALAN. However, near the bridge where street lines shine, search volume is much greater. Predation risk is significantly elevated near the Fremont Bridge, attributable to unshielded street lights rather than the art lights.
06:00 PM
EVALUATING THE EFFECTS OF CORAL BLEACHING AT A MISSION: ICONIC REEFS CORAL RESTORATION SITE IN THE FLORIDA KEYS NATIONAL MARINE SANCTUARY (9084)
Primary Presenter: Mia Gomez, Florida Atlantic University Harriet L. Wilkes Honors College (mialgz03@gmail.com)
Coral reefs worldwide have been significantly stressed by high ocean temperatures in the past year during the fourth global coral bleaching event. From June to September 2023, the Florida reef tract experienced severe coral bleaching. Cheeca Rocks is a historically abundant, biodiverse, and resilient patch reef monitored under the Florida Keys National Marine Sanctuary’s Mission: Iconic Reefs restoration effort. To quantify the impacts of this bleaching event on a high coral cover reef site, I compared orthophotomosaic imagery collected at one 10-meter by 10-meter Cheeca Rocks restoration monitoring plot in June 2022, before the bleaching event, and in May 2024, after the bleaching event. I quantified the benthic cover (%) of corals by using TagLab software to annotate coral colonies. Results showed a decrease in coral cover, an increase in mortality on coral colonies, and an increase in turf macroalgae in 2024. Coral cover decreased from 35 to 27%, and turf macroalgae increased from 12 to 25% in 2024 relative to 2022. Overall, Orbicella spp. and Siderastrea spp. maintained the highest coral cover, even after bleaching. However, Orbicella faveolata, an ESA-listed threatened species, showed the largest decline in cover, from 28 to 20%. Coral colony mortality was most prevalent on the tops of coral colonies, potentially due to increased exposure to high solar irradiance. Results demonstrate the importance of continued coral reef monitoring to quantify climate-based disturbances and ecological resilience, and to inform restoration design and implementation.
06:00 PM
EVALUATING SEDIMENTATION PATTERNS BETWEEN 2014-2017 IN CORAL BAY, ST. JOHN, US VIRGIN ISLANDS: (9752)
Primary Presenter: Prudence Criscuolo, Eckerd College (pcriscuolo@eckerd.edu)
The 2017 hurricane season battered Coral Bay, St. John, USVI. Recent building of roads and infrastructure has set up St. John for increased sedimentation into Coral Bay, especially during storm events like hurricanes. Previous studies indicated that widespread deposition occurred in the bay due to 2017 hurricanes Irma, Jose, and Maria. This study aims to analyze several sites in Coral Bay, using X-Ray Fluorescence (XRF) to identify differences in elemental concentrations for each site. We used discrete surface samples from each site from 2014 and 2017 to find how these sites have changed temporally and spatially. In addition, we analyzed the mud grain size fraction from 2017 to determine if there was substantial difference in element concentration. Each site was chosen based on available samples and data, as well as proximity and distance to and from possible sources of sedimentation. Interpretation of the XRF data indicated that there was a considerable difference in elemental concentrations between the 2014 and 2017 samples, especially in elements like Sr, Mg, Ca (marine indicators), Ti, Si, Fe, and Al (terrigenous indicators). By normalizing to Ca and Al using ratio analysis, we can identify which sites had a prominent change in terrigenous or marine input. Our data suggest that each site experienced different sedimentation sources due these variations. These findings lead to questions such as where these sources are located, if they are indicative of contaminants, and if they are characteristic of this area, all of which can be addressed with further time and analysis.
06:00 PM
DOES CHRONIC EXPOSURE TO ENVIRONMENTAL STRESS INCREASE EASTERN OYSTER (CRASSOSTREA VIRGINICA) RESILIENCE TO NEW STRESSORS? (9121)
Primary Presenter: Rebecca Goldman, Washington and Lee (rgoldman@mail.wlu.edu)
Exposure to environmental stressors can result in alterations to animal physiology, metabolism, microbiome composition, and survival probability. However, we hypothesized that animals with chronic exposure to a multi-faceted stressor like habitat quality degradation may have a lower stress response when exposed to new stressors and harbor microbial symbionts that enhance resilience. To test this, we exposed oysters collected from two Virginia rivers, Hampton (low quality) and Lynnhaven (high quality), to acute thermal stress via rising water temperature in a 14-day aquarium experiment. Oysters (n=54 per river) were divided into control and hot treatments. Control tank water was maintained at 25°C – equivalent to river temperature, and Hot tanks began at 25°C and was raised 1.7°C Day-1 for 6 days to reach a final temp of 33.3°C. Cortisol—a stress-related hormone—was quantified using an ELISA assay. Oysters from hot treatments, especially Lynnhaven, had higher cortisol concentrations indicating increased stress. Clearance rate, how quickly an oyster filters the water (a proxy for metabolic activity), was higher in Lynnhaven-Hot than Hampton-Hot oysters. Preliminary microbiome data shows that oysters living in degraded habitat (e.g., Hampton) maintain a more stable microbiome composition when exposed to a new stressor. Together our preliminary results suggest that chronically-stressed oysters may develop metabolic and microbiome strategies to increase their resilience to new stressors providing hope that oysters can persist as habitat quality decreases and temperatures rise.
06:00 PM
Hot Pockets of the Deep: Sonar Mapping of the Hydrothermal Plumes (9122)
Primary Presenter: Reece Clark, University of North Carolina at Chapel Hill (reececlark55@gmail.com)
Hydrothermal vents are dynamic environments, with variable temperatures driving rising plumes. The larger scales of venting and plume interactions with the ocean are best captured using imaging sonars, where the backscattering of sound is enhanced by the dynamic temperature changes in vents and plumes. Visualizing vent and plume features through various techniques is essential for effective data analysis. We present a novel software application designed to generate animations, maps, and ping averages from data collected by an EM2040 multibeam echosounder. The software reads and processes KMALL and KMWCD data using Val Schmidt’s KMALL library, providing a lightweight tool for rapid visualization and manipulation of water column data. This serves two primary purposes: it allows engineers aboard research cruises to verify the accuracy of water column data collection in real-time, and it offers a user-friendly platform for researchers unfamiliar with water column data to explore and understand the basics. By offering a comprehensive package for water column data research, this tool enhances the usability of multibeam sonar data in studying hydrothermal vent environments.
06:00 PM
THE 2023 AUSTRAL SUMMER PHYTOPLANKTON BLOOM IN THE SOUTHERN OCEAN (9152)
Primary Presenter: Lillian Braun, The University of Maine (lillian.braun@maine.edu)
Phytoplankton plays a significant role in global primary production, providing over half of Earth's carbon fixation. Micronutrients such as trace metals are essential to phytoplankton productivity, and low trace metal concentrations in some regions limits phytoplankton production and the resulting seasonal bloom, thus disrupting the fixation of carbon dioxide. Specifically, the Southern Ocean is one of the most understudied trace metal areas due to its remote nature thus a specifical lack in understanding on the characteristics of the phytoplankton community there. TheGP17-OCE cruise traveled through the Southern Ocean and deployed fourteen BioGeoChemical (BGC) Argo Floats while also conducting CTD casts and trace metal sampling. Using the data collected from the BGC Argo Floats deployed by this cruise, depth profiles of chlorophyll, backscatter, nitrate, and temperature along the cruise track were created to understand the complexity of the austral spring phytoplankton blooms. Knowledge of phytoplankton characteristics was applied to the data collected during the GP17-OCE cruise to further understand the timing and the intensity of the austral spring bloom occurring during December 2022 to July 2023.
06:00 PM
Using UAVs to Monitor Algal Blooms (9298)
Primary Presenter: Caitlyn Walley, University of Tampa (cewalley1046@gmail.com)
This study focused on using Unmanned Arial Vehicles (UAVs) to monitor algal blooms. This study was done based on data collated from Fernandez et. al (Fernandez-Figueroa et al., 2022). An orthomosaic was the final product of each drone flight. Orthomosaics are essentially a bunch of individual photos that are stitched together by similarities and create a full picture. Using the data provided, I created two orthomosaics and calculated the vegetation indices for both compared to actual water samples collected. The RGB imagery was collected using a Phantom 4 drone and the multispectral imagery was collected using a Parrot Sequoia sensor. The vegetation indices used were the Color Index of Vegetation Extraction (CIVE) and Normalized Difference Vegetation Index (NDVI) (Fernandez-Figueroa et al., 2022; Kislik et al., 2018). We found that the most accurate representation for chlorophyll a was using multispectral imagery and comparing it to the point the water sample was taken rather than the whole pond or a buffer around the point. The point provides a more accurate determination of chlorophyll a likely because scum within the ponds saturated the indices and skewed the results.
06:00 PM
DETECTION OF HEAVY METALS IN THE SALT MARSH SUCCULENT GLASSWORT (SALICORNIA SPP) BY X-RAY FLOURESCENCE (9432)
Primary Presenter: Camille Maxwell, University of Massachusetts Boston (maxcamalex@outlook.com)
Heavy metals accumulate in coastal ecosystems such as salt marshes and are known to impact both terrestrial and aquatic life. Without a method of remediation for high levels of metal contaminants, metals can leech and dissolve into water systems, which affect coastal communities, both on shore and in the water. Heavy metals can accumulate in high concentrations in plants, as well shorebird and fish tissue, which poses health risks and lowers fecundity to these species. Certain salt marsh plants such as the succulent, Glasswort (Salicornia spp) are known to bioaccumulate heavy metals such as lead, copper, and zinc, and have been suggested as a possible phytoremediation strategy for contaminated sediments. However, a rapid field method to screen plants’ effectiveness at taking up heavy metals has not been commonly adopted. Therefore, we are evaluating portable X-ray fluorescence as a method for rapidly screening plant tissue samples for a variety of heavy metals in the field. We are examining water content, plant status, parts of the plant impacts, sediment concentration, sample size, processing method on this analysis. These screening measurements on metal contents can help guide more detailed sampling for laboratory analysis and may also allow community stakeholder input into sampling and assessment of heavy metals in coastal environments.
06:00 PM
Examining Variation in Photosynthetic Pigments in Salt Marsh Grass and Seagrass (9477)
Primary Presenter: Jarad Walker, Randolph College (jwalker@randolphcollege.edu)
Grassy coastal ecosystems, including salt marshes and seagrass beds, are highly productive, critical for coastal food webs, and threatened by human activities. This project examined the variability in the photosynthetic pigments found in the tops and bottoms of the blades of Distichlis spicata, a salt marsh grass, and Zostera marina, a subtidal seagrass, across stress gradients for both plants. Chlorophyll a and b were both higher in the top sections of the plants than in the lower sections, and this pattern was more pronounced for the salt marsh grass. The chlorophyll a to b ratio was higher in the salt marsh grass than in the seagrass, but did not vary across the stress gradients for either species. Understanding how these plants allocate these pigments provides insight into how they may respond to future stressors, particularly continued sea level rise.
06:00 PM
TRACKING THE NEW INVADER: QUAGGA MUSSELS OUTCOMPETING ZEBRA MUSSELS IN OTSEGO LAKE, NY, USA (9487)
Primary Presenter: Alabaster Corsette, State University of New York at Oneonta (Alabastercorsette@gmail.com)
Otsego Lake, a 16.37 km2 freshwater glacial lake in New York, USA, has experienced serial invasions by the zebra mussel (Dreissena polymorpha) starting in 2007 and quagga mussel (Dreissena rostriformis bugensis) reported in 2020. To capture population dynamics during the early stage of the quagga mussel establishment against the already established zebra mussel population, three undergraduate students deployed a series of mussel sampler plates at near shore sites in February-May and July-October 2021 (without temperature loggers) and January-July 2022 (with temperature loggers) at three depths down to z = 22 m. Over 8000 individuals of the two species were collected and the following data were recorded: length, species, and estimated age based on annual ring counts, with a small set of samples bisected to evaluate accuracy of the visual annual ring identification method. The results showed that the invasive mussels found at lower depths in Otsego Lake tend to be older for their size, suggesting slower growth. Analysis of temperature data will be presented.
06:00 PM
FLUOROMETRIC ASSAY FOR THE DETECTION OF METHANOL IN AQUATIC ENVIRONMENTS AND BACTERIAL CULTURES (9502)
Primary Presenter: Keshav Srivenkatesh, University of North Carolina at Chapel Hill (ksrivenkatesh@yahoo.com)
The measurement of ambient methanol in seawater has typically relied on methods requiring a significant time and cost investment, such as liquid or gas chromatography in tandem with mass spectrometry. Methods using colorimetry and fluorescence spectroscopy use cheaper, more accessible instrumentation and reagents that make possible the automation of analysis of large batches of samples. Furthermore, an easily replicable analysis of culture samples, taken from multiple time points and under different growth conditions, can demonstrate where and how methanol is produced, taken up, and utilized over time. Our goal is to develop a fluorometric method for quantifying methanol at nanomolar concentrations typical of lake and seawater. We combined the enzymatic transformation of methanol into formaldehyde with the Hantzsch ester synthesis of the fluorophore 3,5-diacetyl-1,4-dihydrolutidine (DDL) from formaldehyde. We evaluated standard-to-reagent ratio, methods of standard preparation, optimal pH and salinity for enzymatic and organic transformations, and testing both fluorescence and absorbance spectroscopy. Because of the intermediate transformation, we were also able to use this method to quantify formaldehyde. The method is being used to measure methanol and formaldehyde in environmental and bacterial culture samples, elucidating methanol metabolism and drawdown.
06:00 PM
Field studies of the Anyanui Estuary, Ghana, conducted as part of the Cross-cultural Experiential Ocean Research Program (9510)
Primary Presenter: James Lerczak, Oregon State University (jim.lerczak@oregonstate.edu)
The Cross-cultural Experiential Ocean Research Program (CEORP) is a National Science Foundation funded project focused on engaging undergraduate students of diverse backgrounds in ocean research focusing on fieldwork, cultural exchange, and international scientific collaboration with undergraduate students and faculty from the University of Ghana, Hampton University, and Oregon State University. The CEORP program included a two-week field campaign in August 2023 in Ghana in which students developed and executed field sampling projects to study the Anyaniu River, a channel of the Volta Estuary system. A description of the field projects and a summary of the findings are described in this presentation. Projects focused on quantifying spatial and temporal variations in basic estuarine properties (e.g., salinity, temperature) and concentrations of several biogeochemical quantities (e.g., Ph, ammonia, phosphorus, copper and magnesium). Additionally, the types and concentrations of microplastics within the estuary were quantified. A goal of this research was to collect basic data toward understanding the impacts on the health of the estuary from mangrove cutting, fishing, and channel closures.
06:00 PM
TEMPERATURE IMPACTS ON THE ABUNDANCE AND GROWTH RATE OF PSEUDO-NITZSCHIA SPECIES LOCAL TO MONTEREY BAY, CALIFORNIA (9523)
Primary Presenter: Maya Clarke, Florida Atlantic University (mayaclarke2021@fau.edu)
Harmful Algae Blooms (HABs) are a global issue that occur when toxic phytoplankton, like species in the pennate diatom genus Pseudo-nitzschia (PN), capitalize on favorable water conditions to form dense physical aggregations. Monterey Bay (MB), California has experienced severe HAB events recently in conjunction with warm sea surface temperature (SST) anomalies One of the most toxic HABs followed the 2015 Pacific Marine Heat Wave (MHW) that warmed MB to over 15°C. Natural processes like El Niño Southern Oscillation (ENSO) events and anthropogenic activities can contribute to similar warming, and models predict a 1-3°C rise in global SSTs. We seek to understand how the abundance of PN species local to MB respond to these temperature increases to better predict HAB threats by establishing growth rate and abundance measures at the current average MB SST, 12°C. We expected both measurements to be greater from P. multiseries than P. pungens, due to its prevalence in prior HABs. This study employed growth rate experiments to compare the two species. We measured species abundance and calculated growth rates from daily cell counts using a Sedgewick Rafter counting chamber. The results support that P. multiseries outperforms P. pungens in abundance and growth rate. Ultimately, HABs threaten to cost coastal communities millions in fisheries closures and pose a hazard to human and marine health. In comparing species at current MB average SSTs, we are establishing a comparison base for future temperature studies and improving HAB monitoring networks and models.
06:00 PM
DEVELOPING A METHOD TO MEASURE CORTICOSTERONE IN FECAL SAMPLES FROM THE KEMP’S RIDLEY SEA TURTLE, LEPIDOCHELYS KEMPII (9559)
Primary Presenter: Ciera Kelley, The University of Texas at Austin (cieramg.kelley@gmail.com)
The critically endangered sea turtle Lepidochelys kempii faces consistent stressors including habitat loss, entanglement, and cold stunning, all of which are exacerbated by the dynamic effects of climate change. These threats may lead to chronically increased levels of the stress hormone corticosterone that can suppress the immune system and increase disease susceptibility. This study validated the measurement of corticosterone in non-invasive fecal samples using a commercially-available Enzyme Immunoassay (EIA). Samples were collected opportunistically from 22 L. kempii during their recovery at Mystic Aquarium’s Animal Rescue Clinic. To measure corticosterone differences throughout rehabilitation, both baseline (collected from healthy animals before release) and experimental (collected throughout rehabilation) samples were collected. After EIA validation via parallelism, recovery, and variability tests, all 71 samples were measured. Results include a significantly lower average concentration of corticosterone in baseline (1413 pg/ml) versus experimental (3391 pg/ml) samples (p<0.05), with values decreasing as animals neared clearance for release. Differences among individuals were also identified, including an individual with anomalously high values (34,924 pg/ml) that experienced long-term illness throughout the study. This study validates the use of this EIA for corticosterone measurement using non-invasive L. kempii fecal samples, methods which will next be used to monitor wild populations and ultimately aid in the conservation of this critically endangered species.
06:00 PM
Loggerhead Sea Turtle Nesting Patterns in Leu of Abiotic Factors (9743)
Primary Presenter: Amanda Puza, Juniata College (puzaal21@juniata.edu)
Loggerhead Sea Turtles (Caretta caretta) are a highly elusive species. Nesting success is affected due to the everchanging climate, but further exploring the elements that make up climate is what’s being researched. This study investigates the nesting patterns of loggerhead sea turtles in relation to key abiotic factors, including precipitation, king tides, turtle activity, and nest locations to take a look at the nesting success at the Tom Yawkey Wildlife Center. The location monitored was South Island, a barrier island off the coast of Georgetown, South Carolina. This island is owned by the South Carolina Department of Natural Resources and is home to a multitude of precious species. Ten summer nesting seasons worth of data were collected and analyzed, amassing over 2,000 nests total, with a success rate of 73%.
06:00 PM
INCREASING OYSTER RECRUITMENT ON ARTIFICIAL REEFS (9602)
Primary Presenter: Kristie Semanchik, Bucknell University (kristiesemanchik@gmail.com)
Living shorelines are structures for coastal protection composed of natural and man-made materials intended to promote ecological enhancement through the recruitment of foundation species. Eastern oysters (Crassostrea virginia) are a common target because they form reefs that provide valuable services such as water filtration, habitat development, and coastal defense. This study examined three ways to optimize recruitment of Crassostrea virginica on low carbon concrete (LCC) used for living shorelines. First, recruitment to LCC modules was compared to traditional materials (shell and rock). Second, the effects of three post-manufacturing surface texturing treatments on recruitment were compared. Third, the effect of a SeaTakTM poly-catechol styrene primer applied via three different solvents was compared against an untreated control. Results indicated that LCC reef units perform as well or better than traditional materials. Surprisingly, surface texturing methods performed significantly worse than the untreated control indicating additional texturing was unnecessary. Finally, there was no clear effect of the different primer solvents on recruitment, however, tests of attachment strength remain to be completed. This research contributed to ongoing efforts to develop resilient coastal protection strategies via the US Defense Advanced Research Projects Agency (DARPA) Reefense Program. Results informed the design and implementation of an experimental oyster reef breakwater at Tyndall Air Force Base near Panama City, Florida USA.
06:00 PM
Analyzing the Relationship Between Hydrodynamics and Water Quality Influenced by Oyster Reefs (9673)
Primary Presenter: Christopher Fan, University of Connecticut (chrisfan100@gmail.com)
Water flow impacts many oyster reef processes, such as feeding behaviors, food availability, particle aggregations in the water column, and the transport of particulate matter or biodeposits. Oyster reefs create flow instabilities that generate drag that slow down particles in the water column, allowing for increased filtration rates. Typically, the sensor used in research to measure water velocity have been Acoustic Doppler Current Profilers (ADCP). We used tilt meters as a cheaper alternative. Previous studies have suggested that tilt meters and ADCPs can yield similar water velocity readings in saltwater systems. However, there is not much prior work done utilizing tilt meters in mesohaline systems such as the Chesapeake Bay. Our study has two components. First, we evaluated the accuracy of tilt meters in estuarine systems. Tilt meter and ADCP water velocity data were collected on Chesapeake Biological Laboratory research pier for one week. Timeseries and regression models were created to observe patterns and correlations of the two sensors. Second, we analyzed the relationship between water quality and velocity in a restoration oyster reef in the St. Mary’s River. Three tilt meters and a water quality sonde were deployed for two weeks among the reef. Timeseries and regression models were used to analyze trends between water quality parameters and water velocity. Tilt meters were found to overestimate ADCP readings by an average of 0.55 cm/s. Preliminary results from the oyster reef suggest there was not any significant relationship between water quality and velocity.
06:00 PM
THE EFFECTS OF STRESS ON EASTERN OYSTERS (CRASSOSTREA VIRGINICA) FOLLOWING EXPOSURE TO MUD CRAB (PANOPEUS HERBSTII) PREDATOR CUES (9145)
Primary Presenter: Estelle Fisher, Washington & Lee University (fishere25@mail.wlu.edu)
Eastern oysters (Crassostrea virginica) provide essential ecosystem services and support the multimillion-dollar shellfish industry, yet their interactions with predators, such as mud crabs (Panopeus herbstii), and resulting impacts on restoration success remain underexplored. We investigated the effects of exposure to mud crab predator cues on oyster stress responses, including changes in cortisol (a stress hormone), microbiome composition, and short-term survivorship. Hatchery-raised oysters, naïve to predators, were exposed to mud crab cues in a 28-day aquarium-based experiment. Oysters and crabs were housed in separate tanks. Weekly, 1L of water from each oyster tank (n=3 per treatment) was removed and replaced with either filtered hatchery water or a 1:1 mixture of hatchery and predator tank water—containing predator-exuded compounds. Oysters (n=9 per treatment) were sampled immediately prior to water changes. Predator cue exposure resulted in an initial spike in cortisol, which diminished over time, while oyster survival remained unaffected. Preliminary microbiome analysis of predator cue-exposed oysters using 16S rRNA gene sequencing revealed shifts in bacterial communities, with an increase in both beneficial taxa (e.g., Endozoicomonas) and opportunistic pathogens (e.g., Shewanella, Arcobacter). Overall, we demonstrate that while predator presence induces stress and alters microbiome composition, it does not significantly impact oyster survival under controlled laboratory conditions, suggesting that predator cues alone are unlikely to impede restoration efforts.
06:00 PM
A Preliminary Study of Macrofaunal Communities at the Novel Hydrothermal Vent Field “Dymond” Near the Base of Axial Seamount (9653)
Primary Presenter: Morrigan Havely, University of Washington (mhavely@outlook.com)
Hydrothermal vents occur along all mid-ocean ridge spreading centers and are one of the most extreme environments on Earth, supporting novel life forms in the absence of sunlight. Here, remarkable microbial communities form the base of the food chain to sustain rich macrofaunal assemblages. In 2011, an unusual hydrothermal vent field was discovered, during an NSF-funded Ocean Observatories Regional Cabled Array cruise, the “Dymond field” at a water depth of ~1990 meters, near the base of Axial Seamount on the Juan de Fuca ridge. It is underlain by a secondary magma chamber residing ~ 16 km southwest of an extensive chamber underlying Axial Caldera, 1500 m below sea level. The largest hydrothermally active, complex edifice in Dymond rises ~60 m above the seafloor. It hosts multiple pinnacles and numerous vents that are notably different from those within Axial Caldera. Rare, small orifices emit particle-free fluids with chimlets and surrounding deposits covered in extremely thick orange microbial mats and oxidized substrate. These unique microbial mats support a diverse macrofaunal ecosystem. This preliminary work provides the first description of macrofaunal communities at Dymond, which includes Rattail fish (Coryphaenoides acrolepis), Ridgeia tubeworms (Ridgeia piscesae), sea pigs (Scotoplanes globosa), Fathead sculpins (Psychrolutes phrictus), and Juan de Fuca limpets (Lepetodrilus fucensis).
06:00 PM
Biological Snowfall: Analyzing Marine Snow Microstructure and Composition (9672)
Primary Presenter: Dylan Buchmiller, Texas A&M University at Galveston (dylan.buchmiller@tamu.edu)
Much like delicate snowfall, marine snow forms intricate, layered structures composed of organic matter and microbes, playing a critical role in the ocean's carbon cycle through enhanced carbon sequestration. Marine snow is defined as the macroscopic aggregates (greater than 500 micrometers) of phytoplankton, bacteria, detrital material, minerals, and polymeric materials. The latter falls into two classes: extracellular polymeric substance (EPS) and transparent exopolymer particles (TEP). EPS (both polysaccharides and proteins) and TEP (polysaccharides) are operationally defined, and reflect measurements of different components of the polymeric milieu. This research introduces a novel staining technique that combines Concanavalin A, Alcian Blue, and DAPI to visualize and quantify each component within marine snow aggregates. This developed method addresses the limitations of previous research by providing an enhanced view of individual aggregates. Key objectives include determining the relative areas and proportions of EPS, TEP, and bacteria within aggregates and comparing them with surrounding seawater both before and after marine snow formation using roller tanks. Furthermore, this approach facilitates comparative studies across different environments, such as pelagic and neritic zones, as well as seasonal variations. The visual results will also serve to validate traditional spectrophotometric methods. Ultimately, this research aims to enrich future modeling efforts by incorporating more precise parameters related to microbial interactions and marine snow.
SS02P - Undergraduate Research in Marine and Aquatic Sciences
Description
Time: 6:00 PM
Date: 29/3/2025
Room: Exhibit Hall A