Microplastics occurrence and spatial distribution in seawater and sediment of Haikou Bay in the northern South China Sea
This study investigated microplastics (MPs) pollution in Haikou Bay in the northern South China Sea (SCS). Eight sampling sites were selected on the basis of their functions as hotel-intensive areas, public beaches, harbors, municipal discharge sites, and public waters. A total of 1053 putative plastic particles of which 1019 were from seawater and 34 from sediment were collected using 333 μm nylon Neuston nets and a bottom collector, respectively. The results showed that the abundance of MPs ranged from 0.26 to 0.84 items/m3 (hereafter defined as n/m3) in the surface water and 0.66 ± 0.58 n/50 g (d.w.)-17.00 ± 6.56 n/50 g (d.w.) in the sediment of Haikou Bay. For the surface seawater samples, the predominant MPs were fibers (83.12%) in rayon (52.73%). For the sediment samples, MPs were predominantly in fibers (67.65%), while PE (28.41%), polyolefin (25.50%), rayon (23.53%) were frequently detected. MPs are widely found in coastal seawater and sediment, but with different abundance in different functional areas. A higher abundance of MPs was found in the seawaters of public beaches and sediments of sewage discharge ditches. Our results highlight the occurrence of MPs in Haikou Bay, and we also offer field study results for the evaluation of environmental risks posed by MPs in the northern SCS.