Widespread Microplastic Pollution in Central Appalachian Streams: Implications for Freshwater Ecosystem Sustainability

Microplastic pollution levels and potential sources of contamination in North Central Appalachia are evaluated to fill a major knowledge gap regarding microplastics in freshwater systems, which lead to negative consequences for the sustainability of healthy freshwaters. Fifty-five northern hogsucker fish were sampled from nine sites throughout seven freshwater streams in the region. Microplastic particles were extracted from the gastrointestinal (GI) tracts via 10% KOH digestion and identified visually. A total of 2185 particles were identified, ranging between 8 and 274 particles/individual and an average of 39.73 particles/individual. The most particles were found in fish within the Cheat watershed, particularly at the Big Sandy Creek downstream site, followed by tributaries of the Monongahela and Ohio Rivers. The most identified particle type was fiber (96.61%). There was a positive relationship between the total length of fish and number of particles. Agricultural land use and E. coli abundance were both positively correlated with microplastic abundance. Agricultural land use and sewage input both appear to be important drivers of microplastic pollution in these streams, although we cannot rule out the influence of atmospheric deposition. These results point to widespread levels of microplastic contamination in freshwater ecosystems in North Central Appalachia.