Assessing the Utility of Environmental DNA Techniques to Monitor White Shrimp (LITOPENAEUS SETIFERUS) Abundance on the Georgia Coast

Environmental DNA (eDNA) surveys have developed over the last decade from once being a novel tool to now acting as an effective technology often used in complement to traditional capture surveys for assessing the distribution of organisms in freshwater and marine environments. However, many uncertainties on how to properly develop, operate, and analyze eDNA based techniques still hinder this technology effectiveness in the field. The white shrimp, Litopenaeus setiferus, is a common, commercially and recreationally important species in the United States, with landings exceeding $254 million in 2020. L. setiferus is also used as a key indicator species to changes in estuarine water quality and habitat. Given the commercial and ecological value of L. setiferus, they represented a useful species to explore the utility of eDNA techniques for fishery monitoring. In this study, I examined how L. setiferus abundance and biomass correlated to the amount of eDNA found in the environment, while investigating how factors like temperature effect eDNA detection over time. However, this study yielded mixed results bearing difficulties with assay specificity, and sample amplification, highlighting the challenges associated with using eDNA sampling on marine crustaceans. Ultimately, these findings emphasized the need for standardized assay validations and the importance of appropriate selection of target species, environment, sampling, and detection method before trying to comprehensively use eDNA technologies for fisheries management

Abundance of Microplastics in Freshwater Streams of Rural Areas

A relatively new type of pollutant called microplastics have emerged in freshwater streams that can cause damage to wildlife and the overall health of aquatic ecosystems. Microplastics are tiny pieces of plastic around 5mm or smaller that are showing up all over the world in aquatic and marine environments. These microplastics are being produced by a number of different sources; one being microbeads, which are miniscule pieces of polyethylene, used in cosmetics and exfoliating beauty products. While other sources come from larger pieces of plastic debris that have further broken down into smaller pieces over time, these small particles of plastic are passing through the filtration systems of wastewater treatment plants with ease and into the surrounding streams. With wastewater treatment plants being the gateway for microplastics into aquatic ecosystems, we will be testing for a significant difference in the concentrations of microplastics upstream from the plants versus downstream. Samples will be taken every week in the stream surrounding the Village of Morton\u27s wastewater treatment plant, both upstream of the effluent and downstream of the effluent. The samples will then be taken to the laboratory and processed using standardized methods to dry out and digest the organic material from the original samples, leaving behind the microplastics to be sorted and counted. We predict that, because the filtration systems of most wastewater treatment plants are not well suited to stop microplastics, there will be a higher concentration downstream of the effluent than upstream of the effluent. We also predict that the microplastics found will contain more microfibers rather than microbeads due to the Microbead-Free Waters Act of 2015. Microplastics have been thought to be substantially more concentrated in highly populated areas like big cities, but evidence of microplastics now being present in rural areas suggests that these little particles are becoming a much larger problem

MICROPLASTIC CONCENTRATIONS IN GIZZARD SHAD (DOROSOMA CEPEDIANUM) AND LARGEMOUTH BASS (MICROPTERUS SALMOIDES) FROM TWO DRINKING WATER RESERVOIRS IN THE MIDWESTERN UNITED STATES.

The emergence of microplastics as a widespread contaminant in marine and freshwater environments has been cause for concern. Not only can these particles be a source of persistent organic pollutants and harmful microbial assemblages, but microplastics also have the potential to impact feeding and physiological functions of organisms. To date, most environmental and ecological studies of microplastics have focused on marine systems. Research in freshwater environments has been limited, especially with respect to ingestion across trophic levels. In this study, we explored microplastic concentrations in freshwater fish and whether these concentrations were influenced by landscape or food web characteristics. We sampled gizzard shad and largemouth bass from two drinking water reservoirs in the central Midwest that have differing shoreline land use patterns. We anticipated that the reservoir with permanent residences would have greater microplastic concentrations than the one in protected parkland. We examined whether feeding guild influenced where microplastics where concentrated within fish and whether there was evidence of trophic transfer. Our results to date indicate that microplastics concentrations are similar to those found in riverine fishes, although generally slightly higher