Occurrence of microplastics in the coastal marine environment: First observation on sediment of China

•The quantity and composition of microplastics are investigated at 5 sediment sites in China for the first time.•The number of microplastics was at the range of 251–436 items/50 g sediment.•Polyesters, polyethylene terephthalate, high density polyesters and polystyrene were identified using u-FTIR.

Microplastics in sediments from the Beibu Gulf and the coastline of China Sea were investigated to evaluate the occurrence and abundance of microplastics in China for the first time. Microplastics (<5 mm) were taken from sediments by a flotation method. The number of microplastics was counted by a fluorescence microscope, an instrument that is rarely used in the detection of microplastics in sediments. This instrument led to results that were satisfactory. Compared with other sampled areas, microplastics were found in massive concentrations in China. Four types of microplastics, HDPE, PET, PE and PS, were identified. The results will provide useful background information for further investigations.