Seasonal Variation of Microplastic Contamination in Edible Bivalves (Green Mussels and Clams) from the Bay of Bengal Coast, Bangladesh

Microplastics (MPs) are increasingly found more often in aquatic environments, and filter-feeding bivalves can ingest MPs, potentially exposing humans. To our knowledge, seasonal data on microplastic loads in edible marine bivalves from the Bay of Bengal coast of Bangladesh remain limited. Here, we measured the number of MPs contamination in the soft tissues of green mussels (Perna viridis) and three types of clams (Meretrix lusoria, Meretrix lyrata, and Tegilarca granosa) collected from the Bay of Bengal coast. MP load (items individual⁻¹) was higher in winter than in monsoon for both mussels (54 vs 20 items individual⁻¹) and clams (44 vs 19 items individual⁻¹). Across species and seasons, MPs < 1 mm were most common, and the dominant shapes were fibers, fragments, and filaments; and the dominant colors were black, blue, and transparent. Polyamide/nylon (PA), polyvinyl chloride (PVC), and polyethylene (PE) were among the most frequently detected polymers. These results show that there are high levels of MPs in the edible bivalves from the Bay of Bengal coast, which can threaten the seafood safety.