Microplastic uptake in commercial fishes from the Bohai Sea, China

Microplastic (MP) pollution has become an emerging global concern in marine environments, but research on the uptake of MPs by commercial marine fish is relatively sparse. In this study, 29 commercial fish species (n = 584) with different feeding habits and trophic levels were collected from 8 sites along the Bohai Sea for MP uptake analysis. Approximately 85.4% of the total fish among all species ingested MPs, and there was an average abundance of 2.14 items/individual or 0.043 items/g of wet weight. Compared with other studies, MP pollution in fishes from the Bohai Sea was relatively moderate. The MPs were predominantly fibrous in shape and were cellophane, polyethylene terephthalate (PET) and polypropylene (PP) in polymer composition. The highest abundance and polymer composition of MPs was observed in benthivores, suggesting that they might ingest these MPs from their food. The small fish Konosirus punctatus, which had a high level of MPs, may increase the risk of human exposure to the MPs when it is dried and consumed. Moreover, the spatial variation of MPs was determined in terms of abundance, shape composition, and major polymer types, but there was no marked relationship between MP abundance and the trophic levels of fish. Overall, this study provides a basis for the ecological risk assessment of MPs in fish and for a health risk assessment for human beings.