Environmental risks of microplastics: A Review of their distribution and effects on aquatic ecosystems

Microplastics, as globally emerging pollutants, threaten aquatic ecosystems through dual mechanisms: (1) exerting direct physicochemical stress on organisms, and (2) interacting synergistically with co-existing pollutants, ultimately disrupting food web integrity and jeopardizing both ecological security and human health. However, research on the ecological risks of microplastics faces important gaps: first, experimental conditions differ significantly from real environmental conditions, making it difficult to accurately simulate chronic low-dose exposure scenarios; second, cross-scale risk assessments from the molecular to the ecosystem level are lacking. This severely hinders the accurate understanding and effective management of microplastic risks in aquaculture systems. Based on this, this study systematically integrates the cross-scale mechanisms of microplastic impacts on aquatic organisms, focusing on their environmental distribution, biological exposure pathways, and bioaccumulation characteristics to elucidate their toxic effects and ecological risks. The study reveals the “individual-community-system” cascade effect of microplastics on aquatic ecosystems, and then proposes standardized suggestions for risk assessment of microplastics in aquaculture, providing a theoretical basis and practical guidance for risk control of microplastics in both natural and aquaculture systems.