This session is for undergraduate and beginning graduate students, primarily affiliated with the ASLO Multicultural Program (ASLOMP). Students will present their research findings in a friendly atmosphere that encourages constructive criticism. Appropriate submission from students not affiliated with ASLOMP will also be considered. Students may present in this session only once. They are encouraged to present subsequent work in regular sessions.
Lead Organizer: Benjamin Cuker, Hampton University (benjamin.cuker@hamptonu.edu)
Co-organizers:
Tiara Moore, Black in Marine Science (ceo@bims.org)
Deidre Gibson, Hampton University (Deidre.gibson@hamptonu.edu)
Presentations
03:00 PM
Assessing the deployment strategies for DinoSHIELDs to control harmful dinoflagellates: a field study (5250)
Primary Presenter: Chloe Jones, University of Delaware (chloemj.012@gmail.com)
Harmful algal bloom (HAB) species prompt concerns due to their ability to release toxins into the water and instigate severe outcomes to aquatic systems and human health. A proposed environmentally friendly approach to controlling harmful blooms has centered around Shewanella sp. IRI-160, a bacterium that produces an algicidal compound that target a group of toxic algal species, the dinoflagellates. Both Shewanella sp. IRI-160 and toxic dinoflagellates are found in the Delaware Inland Bays (DIB). DinoSHIELD technology was designed to control dinoflagellate growth through the immobilization of Shewanella sp. IRI-160 in alginate hydrogel beads. Little research has been conducted to test the efficacy of DinoSHIELDs on dinoflagellates outside of the laboratory. This study evaluated strategies for the deployment of DinoSHIELDs in the environment at different water flow condition sites. Two trials were conducted, one with a 24-hour deployment period and one with a seven-day deployment period. Results indicated that the deployment of DinoSHIELDs was effective in decreasing the dinoflagellate growth for trial two, though not for trial one. Overall, the deployment of DinoSHIELDs was effective at mitigating the dinoflagellate abundance at the low flow site following a seven-day deployment period. This suggests that DinoSHIELDs could be an applicable approach to controlling the growth of harmful dinoflagellates in the broader environment.
03:15 PM
UNDERSTANDING THE EFFECTS OF STOCKING DENSITY AND BIOFOULING CONTROL PRACTICES ON BIOFOULING ON OFF-BOTTOM OYSTER GROW-OUT BAGS (YORK RIVER, VA) (5267)
Primary Presenter: Zophia Galvan Lam, Frostburg State University (z.galvan@outlook.com)
Virginia, the top producer of Crassostrea virginica (Eastern Oyster) on the United States East Coast, supports a substantial commercial shellfish aquaculture industry valued at over $30 million. Biofouling, the aquatic communities that adhere to submerged structures, can have ecologic, biologic, and economic impacts on aquaculture operations. Colonized bags have increased weights that affect handling and blockages that can impede essential water flow, which could affect conditions within grow-out bags and have dramatic effects on oyster production costs and final market price. This study aimed to (1) identify and quantify fouling communities and (2) determine the effects of biofouling control practices and stocking density on biofouling communities measured by assessing, (a) biofouling weight on oyster bags and (b) biofouling on mesh settlement plates attached on the outside and suspended within floating oyster bags subjected to the different treatment combinations. Colonizing organisms (tubeworm fouling and bryozoans) were the most prominent taxa found across most settlement mesh plates. Air drying frequently reduced biofouling, producing significantly lighter wet weights on mesh plates and grow-out bags than non-air-dried treatments (p < 0.01). While not significant, higher stocking density tended to reduce biofouling in non-air-dried treatments. Understanding which biofouling communities grow on oyster bags and developing mechanisms to control fouling growth can help researchers provide better data for oyster farmers so they can make more informed husbandry decisions.
03:30 PM
Dietary Ecology of Extant Marine Mammals as Inferred from Dental Microwear Texture Analysis (6046)
Primary Presenter: Ashley Rogers, Vanderbilt University (ashley.d.rogers@vanderbilt.edu)
Dental microwear texture analysis (DMTA) has clarified the dietary ecology of extant and extinct species over the past 20 years, with a focus on terrestrial organisms. The main goal of this study is to assess the effectiveness of DMTA as a tool to interpret diets of the common bottlenose dolphin, orca, beluga whale, walrus, sea otter, and sperm whale. Our preliminary results indicate that marine mammals such as sea otters, beluga whales, walruses and sperm whales eat significantly harder foods (with higher complexity, Asfc values) than the primarily fish consuming common bottlenose dolphin and orca. Additionally, there is little to no evidence that orcas, with the lowest Asfc values, are durophagous (i.e., eating hard foods). There is clear evidence that dolphins and orcas are consuming softer foods than the remaining taxa– which are known to eat invertebrates such as crustaceans and mollusks. Consequently, we found that dental microwear may be an effective tool to analyze the diets of extant and potentially extinct marine mammals, as the surface textures on their teeth correspond with observed diets. Dental microwear texture analysis may allow us to better understand the effects of climate change on marine mammal diets and may be used to track dietary changes from marine mammals in the historical past. It may also be used to potentially aid in developing conservation and management strategies.
03:45 PM
Zooplankton Diversity and Composition in the California Current Ecosystem (CCE): a Size-Structured Metabarcoding Approach (6164)
Primary Presenter: Hannah Budroe, UC San Diego (budroe.hannah@gmail.com)
The California Current Ecosystem (CCE) is a coastal ecosystem that has been impacted by warming and other climate-change associated phenomena in past years. The CCE is oceanographically complex, with northerly currents contributing waters from the North Pacific and Subarctic, an undercurrent carrying tropical waters north, and seasonal upwelling leading to a strong cross-shore gradient in productivity. Though zooplankton play important ecological roles, much of their diversity is understudied, and traditional taxonomic methods can require extensive resources and expertise. Here we used DNA metabarcoding of the cytochrome oxidase I (COI) and 18S rRNA on size separated plankton tissue samples, to investigate diversity patterns across a longitudinal gradient spanning a large range of abiotic factors from coastal upwelling to 800 km offshore. The two markers presented compositionally distinct, yet complementary, perspectives of total plankton diversity, thus demonstrating the value of using multiple primers for broader views of pelagic diversity. Results revealed a cross-shore shift in mesozooplankton community composition correlated with temperature, nutrient concentrations, and primarily characterized by differences in size. Larger key arthropods were most abundant in nearshore communities, with greater richness of small zooplankton further offshore. This study forms a unique size-structured baseline characterizing zooplankton communities across a large environmental gradient that will enhance our ability to detect ecosystem shifts in response to global climate change.
04:00 PM
CARBON BUDGET OF CENTROPAGES HAMATUS IN THE WARMING GULF OF MAINE (4647)
Primary Presenter: Brendan Kellogg, Southern Maine Community College (brenkellogg97@gmail.com)
In most marine ecosystems small planktonic crustaceans form the base of the food web linking primary producers with higher trophic levels including commercially important species such as lobsters and finfish and charismatic megafauna such as seabirds and whales. Climate change is warming the world’s oceans, reorganizing the biogeography of local species and the community structure ecosystems worldwide. The Gulf of Maine is warming faster than other parts of the ocean causing keystone lipid rich copepod species such as Calanus finmarchicus appear to be moving northward to colder waters, while smaller, less fat copepods such as Centropages hamatus are becoming more abundant. This study investigated the energy budget of C. hamatus to increasing temperatures. Grazing and oxygen consumptions rates were measured at 8, 12, 16, and 21°C to determine how temperature affects the carbon accumulation rates. The data shows that as temperatures increase, both ingestion and respiration rates increased with an average Q10 of 2.39 and 1.52 respectively, suggesting an optimal temperature of ~16°C and with the sufficient scope of growth that extends up to 21°C+. These results suggest that as temperatures rise in the Gulf of Maine, C. hamatus will be able to survive the warmer water better than C. finmarchicus.
04:15 PM
A NOVEL HYDROGENOTROPHIC SUBSURFACE BACTERIA PHYLUM FROM THE COSTA RICAN MARGIN (6199)
Primary Presenter: Jacob Williams, Temple University (jacobwilliams6958@gmail.com)
We employed metagenome-assembled genomics to successfully obtain 24 good quality MAGs ranging from (54-92%) in completeness with considerably low contamination levels (<10%) across samples from 2-92 meters below seafloor from the IODP Expedition 334 in the Costa Rican margin. Interestingly, the taxonomic assignments of 3 MAGs belonged to a novel bacterial phylum as supported by both GTDB-tk and ribosomal protein based analyses. Differential coverage analysis of the recovered MAGs across CR datasets indicated that this novel phylum was the most abundant in the deepest parts of the cores at both Site U1378 and U1379, down to 92 meters below seafloor. The collective metabolic reconstruction of this novel phylum indicated the presence of hydrogenic capacities using diverse groups of FeFe, NiFe and NiFeSe hydrogenases. Detailed metabolic reconstruction of the MAGs indicated the presence of genes encoding for anaerobic processing of benthic gasses, in particular hydrogen, to create a proton motive force fueling their ATP synthase to yield energy as well as carbon-dioxide fixation pathways, especially the Wood-Ljungdahl pathway. We hypothesize that this bacteria cross-feeds neighboring microbes due to the presence of a large number of secondary metabolites and co-factors biosynthetic genes, as well as macromolecule biosynthetic pathways, coupled with a large set of transporters and secretory proteins. This novel subsurface-specific phylum most likely plays a role in recycling hydrogen from both geologic or biologic sources and sharing metabolites with the neighboring microbes.
SS001C ASLO Multicultural Program Student Symposium
Description
Time: 3:00 PM
Date: 8/6/2023
Room: Sala Ibiza B