Microplastics in the waters of the western Arctic Ocean during the cruise MR23-06C of the R/V Mirai of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC)

The Arctic Ocean on the Pacific side is one of the potential accumulation areas of plastic debris from the Pacific Ocean due to the Pacific water inflow through the Bering Strait. However, quantitative data on microplastics (MPs) have been reported mainly for the Arctic Ocean on the Atlantic side, and the data on MPs in the Arctic Ocean on the Pacific side are very limited. The Arctic Ocean on the Pacific side has already been subjected to multiple environmental stresses, such as increased surface water temperatures, ocean acidification, and stratification enhancement, due to global warming and the resulting sea ice melting in the Arctic Ocean. Therefore, the influx of MPs and attached microbial communities (Plastisphere) from the Pacific Ocean may further increase environmental stresses on marine ecosystems, and it is an urgent task to quantitatively clarify the current status of MPs pollution in the Arctic Ocean on the Pacific side.
In order to predict the future impact of marine microplastic pollution on marine ecosystems and biogeochemical cycles in the Arctic Ocean, we collected neuston net samples and filtered seawater samples at multiple depths in the Arctic Ocean on the Pacific side, and clarify the followings:
/Inventory of MPs in the Arctic Ocean on the Pacific side (Especially, the Canada Basin and East Siberian Sea)
/Abundance of MPs entering the Arctic Ocean from the Pacific Ocean (Bering Strait)
/Composition of plastisphere present in or entering the Arctic Ocean
/Changes of plastic particles due to the photodegradation