Plastic contamination in coastal areas around Japan: A review

Abstract

Publications describing the concentration and distribution of plastic litter, microplastics（> 350 μm and < 5mm）, and small microplastics（< 350 μm）in seawater, sediments, and beaches around the coast of Japan are reviewed. Plastics from food packaging and polyethylene plastic bags are widely distributed along the Japanese coast. The concentration of expanded plastics and plastic bottles is high in the region of the East China Sea. Microplastics on the sea surface are widely distributed along the coast of Japan, and the average concentration of microplastics in seawater off the Japanese coast is very high compared with other regions of the world. A two-ply, double neuston net, comprising an internal net with a 350-μm mesh and an outer net with a 50-μm mesh, was used to quantify small microplastics（> 50 μm, < 350 μm） and microplastics（> 350 μm, < 5 mm）in Tokyo Bay. The concentration of small microplastics was about 10 times the concentration of microplastics. Conventional techniques used to quantify microplastics may underestimate plastic concentrations.