Plastic pollution of the Kuril–Kamchatka Trench area (NW pacific)

Abstract

During the German–Russian expedition KuramBio (Kuril–Kamchatka Biodiversity Studies) to the northwest Pacific Kuril–Kamchatka Trench and its adjacent abyssal plain, we found several kinds and sizes of plastic debris ranging from fishing nets and packaging to microplastic in the sediment of the deep-sea floor. Microplastics were ubiquitous in the smaller fractions of the box corer samples from every station from depths between 4869 and 5766m. They were found on the abyssal plain and in the sediments of the trench slope on both sides. The amount of microplastics differed between the stations, with lowest concentration of 60piecesperm2 and highest concentrations of more than 2000piecesperm2. Around 75% of the microplastics (defined here as particles <1mm) we isolated from the sediment samples were fibers. Other particles were paint chips or small cracked pieces of unknown origin. The Kuril–Kamchatka Trench area is known for its very rich marine fauna (Zenkevich, 1963). Yet we can only guess how these microplastics accumulated in the deep sea of the Kuril-Kamchatka Trench area and what consequences the microplastic itself and its adsorbed chemicals will have on this very special and rich deep-sea fauna. But we herewith present an evaluation of the different kinds of plastic debris we found, as a documentation of human impact into the deep sea of this region of the Northwest Pacific.