Evaluation of Corbicula fluminea as a biomonitor of microplastics and other anthropogenic microparticles in an urban stream

The use of biomonitor species for anthropogenic microparticles, including microplastics, can be valuable for improving monitoring frameworks and supporting global comparability when assessing contaminant uptake among biota. This study evaluates Corbicula fluminea (C. fluminea) as a potential biomonitor of anthropogenic microparticles over one year by employing monthly water, sediment, and clam sampling at an urban stream in St. Louis, Missouri, United States. No anthropogenic microparticles were detectable in the stream's water, but its sediment had anthropogenic microparticle levels that ranged from undetectable (4 %) to 188.6 counts/kg. Anthropogenic microparticles in C. fluminea varied from undetectable (in 81 % of individuals) to 31.4 counts/g. The majority of the anthropogenic microparticles in the sediment were microplastics (51 %), but the clams contained mostly cotton fibers (54 %). No significant trend was observed between anthropogenic microparticle amounts in the sediment and C. fluminea. Selective uptake of smaller anthropogenic microparticles of certain material types may have prevented a persistently strong relationship between the clams' and their surrounding environment's anthropogenic microparticle levels. Nonetheless, we identified the utility of C. fluminea to indicate moments of extremely high or low anthropogenic microparticle contents in sediment as well as facilitate global comparisons of freshwater systems.