Distribution and characteristics of microplastics in the tidal flats of Sanya Bay, China

Microplastics are plastic particles with a diameter of less than 5 mm that originate from human activities and are widely present in marine environments, resulting in serious impacts on marine organisms and ecosystems. In this study, 10 sampling sites were set in the tidal flats of Sanya Bay based on functional and depth differences. The samples were collected using the coring sampling method and then statistically analyzed using a stereo microscope. The spatial distribution, size range, color , shape characteristics of the microplastics and pollution level were analyzed. The results revealed that the abundance of microplastics in the tidal flats of Sanya Bay was about 16�51.3 pcs/kg. Vertically, the highest abundance of microplastics occurred in the subtidal zone. Horizontally, the highest abundance of microplastics occurred in the hotel resort area, while the lowest was in the transition zone. The distribution of microplastic abundance was influenced by the tide and by tourist activities. The size of the microplastics ranged primarily from 0.1 to 2 mm, with the highest proportion in the 1�2 mm range. The predominant colors were black, blue, and white; black microplastics accounted for the highest proportion. The shape of the microplastics was predominantly fibrous. The pollution level of microplastics in the tidal flats of Sanya Bay is not high, but the impact of tourism waste cannot be ignored. To address microplastic pollution, it is necessary to strengthen pollution source management and control and to promote environmental awareness. Governments and relevant organizations can take measures to encourage the development and use of sustainable materials and products as alternatives to plastics in order to reduce plastic consumption.