[Distribution and Settlement of Microplastics in the Surface Sediment of Yangtze Estuary]

This study is designed to understand the microplastic contamination in the coastal area of Yangtze estuary. The abundance and distribution profiles of microplastics in the surface sediment of six sampling sites along the Yangtze estuary were examined throughout one year. The detected average concentration of microplastic, including fibers and fragments, in the surface sediment of Yangtze estuary was (3.42±1.31) items ·g^-1 (DW). Sampling during four seasons, in the months of January, April, July, and November, indicated that the highest abundance of microplastics in Yangtze estuary surface sediment occurred in January. A re-suspension experiment showed that microplastics tend to settle in the surface sediment after re-suspension. The distribution and settlement of microplastics along the coastal area has a high concordance with the dynamic erosion-accretion process of the Yangtze estuary. Microplastics tend to settle in accretion sites rather than in erosion sites.