Variations in microplastic pollution characteristics among different aquaculture modes: A case study from Dongting Lake area, China

The widespread presence of microplastics in edible aquatic organisms has attracted considerable global attention, Thus, determining the level of microplastic pollution levels is crucial for ensuring dietary safety. In this study, we investigated microplastic contamination across four aquaculture modes (pond, lake, ecological, and facility) and four aquaculture species (fish, prawn, crab, and swamp eel) in the Dongting Lake area, which is a major region aquaculture area in China. The average abundance of microplastics in the aquaculture water in Dongting Lake was 11.58 ± 3.28 items/L. The pollution level was significantly higher in the swamp eel pond than in the fish, prawn and crab ponds. Integrated wetland purification and high-efficiency water treatment systems in ecological and facility fisheries exhibited significantly lower microplastic abundance compared to traditional aquaculture modes; however, a high concentration of microplastics were detected in the tailwater. These results indicate that the microplastic pollution characteristics across aquaculture systems are influenced by cultured species and operational modes. The implementation of ecological or management measures may be effective in reducing microplastic pollution levels. Our results provide a foundation for assessing microplastic contamination in fisheries and for developing management and remediation strategies.