Comparative analysis of microplastic and microbial communities in varied aquatic environments: Disparities in occurrence, interconnections, and ecological implications

Detection of microplastics (MPs) in various water environments raises significant environmental concerns. However, comprehension of the differences in MPs and their linked biological communities across diverse water settings remains limited. This study explores MPs and their linked microbial communities in the Dongjiang River, Xingfengjiang Reservoirs, and Dayawan Bays watersheds. Our results revealed distinct community compositions of MPs in these three water environments, with higher abundance and diversity integrated index of MPs (p < 0.01) observed in rivers and reservoirs compared to bays. Significant variations in dominant microbial communities and relative abundances were observed among these water bodies, with rivers showing higher Shannon and Simpson indexes than reservoirs and bays. The co-occurrence network analysis indicated more complex and interconnected structures between bacterial communities and MPs in rivers and reservoirs than in bays. Risk assessments conducted for these water environments revealed varying levels of potential risks associated with MPs, with reservoirs posing higher risks than rivers and bays. Noteworthy differences in pathogenic bacteria composition were also identified across the water environments. This study highlights the disparities and connections between MPs and microbial communities in rivers, reservoirs, and bays, providing valuable insights for managing and mitigating MP pollution in diverse aquatic environments.