Occurrence and Effects of Microplastics in Lake Ecosystems: Particular Focus on Migration in Water and Food Chains

Microplastics have become a research hotspot in the environmental field owing to their persistence and complex ecological effects. Although microplastics have attracted public attention only recently, the microplastic pollution in lake, a unique water system characterized by their irreplaceable ecological value and special hydrodynamic conditions, were increasingly documented, calling for a summary of the most recent advance in this research area. Therefore, the sampling and analysis methods, occurrence, sources, and ecological effects of microplastics in lakes were summarized in this review. Various types of plastics are produced and used in large quantities for different purposes, resulting in microplastic pollution being widespread in lakes worldwide, albeit with different levels and characteristics. Microplastics constantly migrate and transform in lake ecosystems, exerting impacts on ecological, including pollution diffusion and biological toxicity. This review focused on the migration of microplastics in water and food chains, which is a different perspective than that considered in previously published reviews. This review also discussed the limitations of existing studies and made recommendations. Future research directions should include the following: 1) improving the baseline database of microplastic pollution in lakes; (2) unifying the sampling and laboratory analysis methods; (3) exploring the quantitative analysis methods of the sources, transportation, and fate of microplastics; (4) considering more factors to explore the effects of microplastics on lake ecosystems.