Abstract
Human activities have generated large quantities of microplastics that can be consumed by filter-feeding organisms as potential food sources. As a result, organisms may experience marked reductions in growth and/or health. To date there has been no investigations connecting microplastics (MPs) with the critically important ribbed mussel Geukensia demissa. Here we examined MP abundances within a bed of G. demissa in New Jersey. Results indicate that MP densities ranged between 11,000–50,000 pieces/m2. The abundance of larger MPs (5 mm ≥ 1 mm) did not vary among sampling sites while the smaller MPs (<1 mm) abundances did vary between sampling sites. These smaller MPs also accounted for 79% of MPs recovered from these sites. Based on the higher abundance of smaller MPs, we also investigated MP ingestion/rejection in a laboratory setting. These results confirmed that ribbed mussels can ingest MPs with negative consequences for the buoyancy of plastics rejected in feces and pseudofeces.
•Marsh microplastic densities ranged between 11,000 and 50,000 pieces/m2.•Microplastics were found in high abundance to sediment depths to 10 cm.•Plastic abundances varied less between sampling sites beneath the mussels.•Adult specimens of Geukensia demissa ingested polystyrene beads (5 μm).•Plastics were in the waste of mussels and became negatively buoyant.