Microplastics Pollution in Freshwater and Marine Fisheries: Sources, Bioaccumulation, Ecotoxicological Impacts, and Sustainable Mitigation Strategies

Microplastic pollution has emerged as a major threat to freshwater and marine fisheries because these particles are now widely detected in water, sediments, and aquatic organisms across both environments. Freshwater systems act both as sinks for land-based plastic waste and as transport corridors delivering microplastics to estuaries and coastal seas, linking inland pollution with marine fishery contamination. In fish and other fishery organisms, microplastics are most commonly reported in the gastrointestinal tract and gills, but experimental and review evidence also indicates translocation to other tissues under some exposure conditions, raising concerns for animal health, food safety, and ecosystem functioning. Ecotoxicological effects reported in the literature include oxidative stress, inflammation, metabolic disturbance, altered feeding and swimming behavior, impaired immunity, and neurotoxicity, particularly when exposure is chronic or combined with co-contaminants such as heavy metals, additives, and persistent organic pollutants. Sustainable mitigation requires interventions across the full plastic life cycle, including source reduction, wastewater control, fishing-gear management, standardized monitoring, circular economy policies, and fishery-specific best practices that reduce environmental inputs without shifting burdens elsewhere.