[Research Progress on Environmental Behavior and Ecological Effects of Microplastics in Reservoirs in China]

Reservoirs are artificial lakes formed by damming water, and the enrichment of pollutants caused by water storage and flood control has become a major ecological problem worldwide. Microplastics enter reservoirs through atmospheric deposition, sewage discharge, and surface runoff and continue to accumulate, not only having a significant impact on reservoir ecosystems but even threatening human health through drinking water and the food chain. To comprehensively understand the status of microplastic pollution in Chinese reservoirs, this study analyzed research articles on microplastic pollution in Chinese reservoirs from 2013 to 2024. This study showed that the average abundance of microplastics in the surface water of Chinese reservoirs was (11 542±15 325) n·m^-3 and (1 408.45±2 659.03) n·kg^-1 in the sediments. The main types of microplastics were polyethylene, polypropylene, and polystyrene, and the particle size distribution of microplastics showed the trend of higher abundance as the size of the particles got smaller. Reservoir construction has changed the natural hydrological situation of the river, and the different hydrodynamic conditions and water environments of the river during the impoundment period and the flood discharge period have had a significant impact on the horizontal and vertical transport behavior of microplastics. In addition, microplastics are prone to form biofilms in closed water bodies of reservoirs and adsorb various pollutants and organic matter, which not only have an impact on the nutrient cycling of the reservoir system but also cause toxic effects when ingested by plants and animals. Finally, this study puts forward the problems that remain to be solved in the future study of microplastic pollution in reservoirs and envisions the future research directions and focuses of microplastic pollution in reservoirs, with a view to providing scientific references for the ecological risk assessment, pollution prevention, and control of microplastic pollution in China's reservoirs.