Unveiling the hidden impacts: A comprehensive review of microplastic effects on marine bivalves

Microplastics (MPs) pollution has become a global environmental issue, posing significant potential risks to marine ecosystems, especially bivalve mollusks. Studies have shown that bivalves are at increased risk of ingesting and accumulating MPs due to their filter-feeding habits, which leads to a series of physiological and ecological consequences. This review highlights the current knowledge gap in the study of MP bioaccumulation in bivalves: The effect of biofilm on MPs' bioaccumulation and selective excretion. The ingestion of MPs can induce oxidative stress and cell damage, impair normal physiological functions, and inhibit bivalve growth, which in turn affects their immune response and overall health. In addition to the effects on individual bivalves, this review innovatively analyzes the adverse ecological consequences of MPs on aquatic ecosystems from the perspectives of nutrient cycling and energy flow. Based on the filter-feeding characteristics of bivalves, we also discuss their potential in mitigating MPs pollution. This review not only summarized the findings in microplastic ecotoxicology research on marine bivalves in recent years, but also provided the perspectives are significant for exploring effective strategies to reduce MPs pollution, protect marine ecosystems, and safeguard human health.