Arctic sea ice is an important temporal sink and means of transport for microplastic

TLDR

Microplastics are an escalating environmental threat that have been detected in high concentrations within sea ice of remote polar regions, and expanding Arctic resource exploitation is expected to increase their load and release during seasonal melt. The study aims to examine how horizontal variability of microplastics within sea ice and the characteristics of the underlying water body influence polymer composition during ice growth. Results show that microplastic composition in sea ice is heterogeneous, with distinct polymer patterns linked to growth region and drift paths, indicating that even in the Arctic, specific microplastics can trace localized sources.

Abstract

Microplastics (MP) are recognized as a growing environmental hazard and have been identified as far as the remote Polar Regions, with particularly high concentrations of microplastics in sea ice. Little is known regarding the horizontal variability of MP within sea ice and how the underlying water body affects MP composition during sea ice growth. Here we show that sea ice MP has no uniform polymer composition and that, depending on the growth region and drift paths of the sea ice, unique MP patterns can be observed in different sea ice horizons. Thus even in remote regions such as the Arctic Ocean, certain MP indicate the presence of localized sources. Increasing exploitation of Arctic resources will likely lead to a higher MP load in the Arctic sea ice and will enhance the release of MP in the areas of strong seasonal sea ice melt and the outflow gateways.