Microplastics (MP, < 5 mm) are found in coastal waters across various environmental compartments (biota, water, marine snow, sediment). These particles can be incorporated into marine snow (heteroaggregations) and sink to the benthos quickly where they interact with benthic organisms. The eastern oyster (Crassostrea virginica) is a commercially important species that has been shown to ingest MP ; however, oysters are discriminant suspension feeders that do not consume all particles to which they are exposed.
This study focused on identification of the polymer compositions, shapes, and sizes of MP found in different environmental compartments on a recreational oyster bed in Norwalk, Connecticut. Oyster, water, marine snow, and sediment samples were collected and the quantity and types of MP in each were determined. Many precautions were taken to minimize and monitor MP contamination in the field and laboratory because quality control and assurance measures are essential for gathering reliable data. The MP were isolated from organics using previously validated digestion and density separation methods. Particles in all samples were viewed under a dissecting microscope and those suspected of being MP isolated and photographed. The size, shape, color, and aspect ratio were determined using microscopy and ImageJ software. The polymers were identified by micro-Fourier transform infrared spectroscopy (FTIR) and only MP with a quality library match (>65%) were considered plastic (Figure 1) . These data will aid in determining the types of MP (polymer composition, shape, size) to which oysters are exposed, and identify those they ingested. Such comparisons are important to determine if MP in the environment are problematic for the eastern oyster and if so, what MP types should be addressed in future environmental policies. Additionally, the dominant MP types and shapes identified in the environment are being used in laboratory exposure experiments to determine MP particle selection.