[Microplastic Pollution of the Beaches in Xiamen Bay, China]

Microplastics are tiny ubiquitous plastic particles smaller than five millimeters (5 mm) in size. Coastal and bay areas are constantly under continuous and increasing pressure from the activities of humans. Microplastic pollution is now recognized as a great threat to these areas. This study was designed to understand the microplastic pollution of the beaches in Xiamen Bay. The results showed that microplastic abundance was from (28.1±9.4) to (312.7±35.2) n·kg^-1. Four main types of microplastics were identified in Xiamen Bay, including fragments, foams, thin films, and fibers. Of the particles analyzed, over 80% were predominantly microplastic fragments and foam, while the films and fiber microplastics accounted for less than 20% of the particles. Studies on the particle size of microplastics also indicated that the microplastics with particle size less than 1 mm accounted for over 60% of the total microparticles, and the abundance of microplastics trend to decrease with increase in the particle size. Fourier transform infrared spectroscopy analysis demonstrated that the major component of the fragments and fibers was identified as polyethylene, and that of foams and films was identified as polystyrene. The scanning electron microscope studies showed that the microplastics presented obvious signs of cracks. In general, Xiamen Bay beach microplastic pollution is at a lower middle level, and land source pollution is the main source of the microplastic pollution.