Abstract
The occurrence of microplastic (MP) pollution in consumer seafood is an increasingly studied and worrying circumstance. Microplastics have been found to negatively impact marine life that ingests them and filter feeding organisms and detritivores are particularly vulnerable. Compounding this, many of these species, like oysters, are foundational species, which provide a variety of valuable ecosystem services and are commercially and culturally significant in communities along the northern Gulf of Mexico (nGoM). Oysters are commonly used as bioindicators of water quality as they are susceptible to marine pollutants and changes in marine ecosystems. Our previous work on MPs in the Mississippi River Basin suggested that the Gulf of Mexico acts as a sink for MP pollution being funneled through the Mississippi River and that the marine life therein is exposed to relatively high levels of MPs compared to other coastlines. In ongoing research, we are analyzing both whole and dissected tissues (digestive tract, mantle, gills) of oysters sourced from multiple sites in the Mississippi Sound to evaluate both the concentration and types of MPs present. Furthermore, the dissection and analysis of individual tissues shows where the MPs accumulate within the oyster. The MPs are extracted and isolated using sample preparation methods newly developed in our laboratory and characterized using multiple techniques, including micro-Fourier Transform Infrared (µ-FTIR) and Laser Direct Infrared (LDIR) Imaging, which provide MP counts, morphologies, polymeric compositions, and sizes. This talk will include discussion of the methodology and preliminary data on the compartmentalization of MPs within Gulf Coast oysters and on the concentrations and characteristics of MPs at oyster reefs in the nGoM.
