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 (cukerbenjamin@gmail.com)
Co-organizers:
Jeanette Davis, Hampton University (Jeanette.davis@hamptonu.edu)
Presentations
02:30 PM
Sprouts in the Chain (8882)
Primary Presenter: Solomon Brooks, Rollins College (Heysolomonbrooks@gmail.com)
A survey of emergent vegetation along the coastline of three local urban lakes in the Central Florida area were analyzed. I separated the lakes into four quadrants (two randomly selected and two chosen) and conducted a drive-by survey, in which a crude visual identification of species occurred, followed by an in-depth transect (along a belt of 5m) survey of the vegetation. Water samples were collected and are going to be sampled and tested for phosphate concentration. In field I sampled the water with a widely accessible Vernier LabQuest 3 probe system to test dissolved oxygen, potassium, nitrate, pH, and temperature. As I progress in this research, I will be conducting statistical analysis on species diversity and comparing how that relates to wider systems of ecological development in the area, as well as looking to see if the vegetation tells any story regarding water quality. I believe that due to human interference whether through nutrient run-off, or through landscaping measure will negatively impact the presence of native emergent and coastal vegetation.
02:45 PM
SPATIAL ANALYSIS OF ZOOPLANKTON FECAL PELLET CARBON EXPORT IN THE WEST ANTARCTIC PENINSULA (8954)
Primary Presenter: Sachi Anand, Brandeis University (sachisanand@gmail.com)
Zooplankton fecal pellets play a significant role in the ocean biological carbon pump through the export of carbon out of the surface ocean. Limited research has been completed in the West Antarctic Peninsula (WAP) on the contribution of fecal pellets to export. As one of the fastest-warming places in the world, the WAP is experiencing rapid ecological change, and understanding trends in fecal pellet carbon export is critical for predicting the future of biogeochemical processes in this region. Fecal pellet export was measured using drifting sediment trap arrays during austral summer 2023 – 2024 on the annual Palmer, Antarctica Long-Term Ecological Research (PAL LTER) cruise. Zooplankton-mediated fecal pellet carbon export was calculated for two sites on the coast of the WAP, and comparisons were made between site locations and sediment trap collection depths. Image analysis was used to measure pellets and calculate fecal pellet volume, which was converted to carbon using published carbon to volume ratios. Total fecal pellet carbon export was higher in the northern coastal site than in the southern coastal site. Additionally, cylindrical pellet export from krill contributed a larger proportion of the total fecal pellet flux in the northern site. Export of ovoid fecal pellets, likely from copepods, significantly increased with increasing depth at the northern site. This research provides the first spatial analysis of zooplankton fecal pellet export in the WAP and highlights the role of zooplankton community structure and fecal pellet export in the biological carbon pump.
03:00 PM
Yellows & Purples of Yellow Island: Characterizing the Hemigrapsus spp. On Yellow Island (9026)
Primary Presenter: Benjamin Brown, University of Louisiana at Lafayette (benmbrown2025@gmail.com)
In the Pacific Northwest region of the United States there are two Hemigrapsus species, the Purple Shore Crab (Hemigrapsus nudus) and the Yellow Shore Crab (Hemigrapsus oregonensis). Shore crabs are intertidal trophic linchpins, consuming intertidal algae and detritus, and serving as a food source for shore birds, sculpin and anemones. These closely related species are differentiated by a few striking differences; most identifiable are the spotted claws in the purple shore crab and hairy legs on the yellow shore crab. General field observations contradicted the literature as many crabs were observed lacking and/or having one or both of the major identifying features along with contradictory and/or undocumented color variation. Morphological methods of identification require updating and the inclusion of habitat preference to increase reliability. Working on Yellow Island, an island in the San Juan Islands of Washington state, crabs were sampled across various substrate types and tidal zones. Size, gender, carapace color and identifiable characteristics were recorded and analyzed. Statistical analysis revealed significant positive correlation between tidal zone and several characteristics despite only 15% of the crabs confirmed as either H. nudus or H. oregonensis. These species, while sometimes overlapping in habitat, do have habitat preferences. A change in the distribution or range of these crabs may be an indicator of changing habitat suitability thus possibly indicating changing distribution for other intertidal species.
03:15 PM
Assessment of Exotic Ichthyofaunal Composition in Colombo’s Urban Wetlands, Sri Lanka (2018–2024) (9134)
Primary Presenter: Gayathra Charuka Bandara Aldeniyagoda Gedara, University of Kelaniya (gayathra.bandara@imbrsea.eu)
Sri Lanka hosts a rich diversity of freshwater fish, with 139 species recorded, including 61 endemics. Colombo, located in the Southwestern province and serving as the country’s economic hub, has an interconnected network of wetlands of significant ecological value. It is the world's only wetland capital city. Given the rapid urban development in the region, this study evaluates the composition of exotic fish species in nine urban wetlands in Colombo from June 2018 to March 2024. The surveyed wetlands included Diyasaru Park (DP), Beddagana Wetland Park (BWP), Thalangama Lake (TL), Diyatha Uyana (DU), Nawala Weli Park (NWP), Heen Canal (HC), Kimbulawala Jogging Pathway (KJP), Bellanwila-Aththidiya Wetland (BAW), and Kotte Rampart Wetland Park (KRW). Fish samples were collected through hand netting and direct visual observation, and all species were identified to the species level. Across the study period, 12 exotic fish species were recorded: Betta splendens, Chitala ornata, Helostoma temminckii, Mayaheros urophthalmus, Oreochromis mossambicus, Oreochromis niloticus, Osphronemus gouramy, Poecilia reticulata, Pterygoplichthys multiradiatus, Tilapia buttikoferi, Trichogaster trichopterus, and Trichopodus pectoralis. The highest proportion of exotic species was found in DP (66.6%), followed by BAW (58.3%), HC (41.6%), and BWP (33.3%), with KRW and DU both at 25%. TL, KJP, and NWP had the lowest proportion (16.6%). Notably, KJP, BAW, HC, BWP, DP, and DU recorded the introduction of 100%, 57%, 40%, 25%, 25%, and 33.3% of exotic species, respectively, primarily due to the ornamental aquarium trade, either deliberately or unintentionally. TL, KRW, and NWP showed no such introductions. In addition, the study recorded 16 native fish species from seven families: Anabantidae, Applocheilidae, Bagridae, Channidae, Cyprinidae, Heteropneustidae, and Osphronemidae. These findings highlight the need for updated monitoring of ichthyofaunal diversity in Colombo’s urban wetlands, which are increasingly threatened by pollution and urbanization. Further research on the ichthyofaunal composition, breeding patterns, population density, and feeding behaviors in larger water bodies within these wetlands is crucial to assess the impact on native species.
03:30 PM
METHANOGENESIS AND NITROGEN FIXATION: UNDERSTANDING THEIR INTERCONNECTION IN FRESHWATER WETLANDS (9270)
Primary Presenter: Lien Tran, Natural Resources Research Institute; University of Minnesota Duluth (Lien21Tran@gmail.com)
Wetlands, the largest source of natural methane, play a significant role in the carbon cycle. A pathway interconnecting wetlands’ carbon and nitrogen cycles is potentially evident as some methanogens harbor nifH, a key gene for nitrogen (N) fixation. To date, the duality of methanogens in performing both processes has largely been underexplored. This study aims to fill knowledge gaps on the strength of this coupling across environmental gradients. We investigated the correlation between methanogenesis and nitrogen fixation rates in freshwater wetlands and used N-15 DNA-stable isotope probing (SIP) to detect nitrogen-fixing microbial communities. Four wetland sites were selected based on unique geochemical characteristics of high iron, sulfate, organic carbon, and low phosphorus levels. The wetland sediments were incubated under atmospheric nitrogen in the dark at 25℃ with the addition of substrates: hydrogen and carbon dioxide (4:1), acetate, trimethylamine, and nothing (control). Over 14 days, methane production and nitrogenase enzyme activity were measured. A significant positive relationship was observed between the methane and nitrogen fixation rate constants normalized to the controls at only the organic carbon-rich wetland (p=0.05, rho=0.68, n=9). Ongoing is the sequencing of N-15 labeled DNA to identify the active N-fixing methanogens. Our study may inform future management actions in response to climate change as we will better understand the interconnectivity of methane emissions and nitrogen cycles in freshwater wetlands.
03:45 PM
SOIL LEGACY OF INVASIVE PHRAGMITES AUSTRALIS FROM MANAGED AND UNMANAGED PLOTS (9363)
Primary Presenter: Tabitha Ormond, University of North Carolina Wilmington (tabithaormond23@gmail.com)
Phragmites australis ssp. australis, which is invasive in coastal areas of North Carolina, is thought to negatively affect native plant populations throughout its invaded range across North America. This study examines ecological impacts of invasive Phragmites on native plants through its effects on soil. We collected soil from four locations across southeastern North Carolina, from plots that had unmanaged Phragmites, managed (herbicide-treated) Phragmites, and adjacent areas that did not contain Phragmites and did not have a known history of management. In total, we used ten unique soil types—two sites with all three soil histories, and two sites with soil collected from just unmanaged Phragmites and adjacent plots. We then planted a rhizome or plug of one of two species of native marsh grasses, Spartina patens and Spartina alterniflora, or of the invasive Phragmites in each soil type (10 soil types x 3 species x 6 replicates = 180 pots). We kept plants in a greenhouse and measured metrics of survival and plant size over three months. We then harvested aboveground and belowground biomass for each plant. We compared growth metrics and biomass measurements between groups to determine whether Phragmites has a lasting soil legacy that impacts native plant growth in managed and unmanaged areas. The results of this study have the potential to inform management decisions regarding the use of herbicides to control Phragmites invasions.
SS01B - ASLO Multicultural Program Student Symposium
Description
Time: 2:30 PM
Date: 27/3/2025
Room: W206A