Mathematical modeling of microplastic spread and fisheries impacts: synthesis of transport parameterization, trophic pathways, and population-level risk assessment

Microplastic (MP) contamination is a globally pervasive stressor in marine and freshwater fisheries ecosystems; however, our quantitative understanding of its transport dynamics, trophic fate, and population-level consequences remains fragmented. This review synthesizes mathematical and computational modeling frameworks used to investigate MP transport, exposure, and ecological impacts in fisheries contexts. We evaluate five principal model classes, hydrodynamic, Eulerian, Lagrangian, statistical, and population-balance approaches, and assess their parameterization of advection–diffusion processes, vertical transport, biofouling-driven density modification, and sediment heteroaggregation across the freshwater, estuarine, coastal, and pelagic continuum. A consistent pattern emerges: MPs bioaccumulate within trophic levels but rarely biomagnify across trophic levels, largely due to rapid gastrointestinal egestion (>80% within 144 hours) and size-selective retention. The principal ecological risk derives from plastic-associated chemical co-transport, including hydrophobic organic contaminants and leaching additives, whose bioaccumulation kinetics may operate independently of particle persistence. Population-dynamic models indicate non-linear, threshold-dependent declines in fish biomass under the combined pressures of microplastic pollution, climate change, and fishing activity. This review provides guidance for ecosystem-based fisheries management and policy-relevant risk assessment. Future research priorities include analytical standardization, taxon-specific elimination kinetics, and the integration of multiple stressors into coupled hydrodynamic–biogeochemical–fisheries models to support robust projections under increasing plastic inputs.