Low concentrations and low spatial variability of marine microplastics in oysters (Crassostrea virginica) in a rural Georgia estuary

• Published in: Marine pollution bulletin Vol. 150; p. 110672
• Main Authors: Keisling, Clarissa, Harris, R. Daniel, Blaze, Julie, Coffin, John, Byers, James E.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-01-2020; Elsevier BV
• Subjects: Animals; Crassostrea; Crassostrea virginica; Distribution; Ecosystem; Environmental Monitoring; Estuaries; Estuarine dynamics; Fetch; Filter feeders; Georgia; Ingestion; Low concentrations; Marine ecosystems; Marine molluscs; Microfibers; Microplastic pollution; Microplastics; Multivariate models; Oysters; Plastics - analysis; Polypropylene; Rural areas; Shellfish; Spatial variations; Water bodies; Water Pollutants, Chemical; Width; Georgia; United States > US; Filter feeders; Microplastics; Crassostrea virginica; Polypropylene; Multivariate models
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2019.110672

Microplastics are an emerging concern for the health of marine ecosystems. In the southeastern US, the filter-feeding Eastern oyster, Crassostrea virginica, is susceptible to microplastic ingestion. We quantified the distribution of microplastics within adult oysters (harvestable size >7.5 cm) from 28 reefs throughout a rural estuary with limited riverine inputs (St. Catherines Sound, Georgia). To determine which variables best predict microplastic concentration in oysters, we also quantified oyster recruitment, distance to ocean, fetch, and water body width. Oysters averaged 0.72 microplastic particles per individual (0.18 particles per gram wet mass); microfragments and microplastics were equally abundant. Although microplastic concentrations were low, multivariate models identified a positive effect of water body width on the site-level concentration of plastic microfibers; average microfragment length was affected by fetch. Our work informs a growing understanding of microplastic distribution in coastal estuaries, providing an important rural contrast to the urbanized estuaries that have been examined.
•Microplastic concentrations in Crassostrea virginica were low in a rural estuary.•Two plastic components—microfibers and microfragments—found at similar abundances.•Water body width correlated positively with microfiber abundance in oysters.•Fetch correlated positively with the size of microfragments in oysters.