Microplastics in polar samples

Microplastics are increasingly recognized as being globally widespread, but relatively little is known about the presence and abundance of microplastics in samples collected in Polar Regions. Here we review the current knowledge about microplastic occurrence and distribution in polar environments, with a particular focus on the relevance of the data and comparability between Arctic and Antarctic investigations. In the Arctic, microplastics have been found in seawater, marine sediments, ice, and snow and in the gut content of several species at different trophic levels. Antarctica is still, by far, the least affected region by human activity than anywhere else in the world, and the few studies carried out in this region find microplastics at very low concentrations. Studies focusing on microplastic threats to key species of Arctic and Antarctic marine food webs are urgently needed as are coordinated long-term studies on microplastic pollution, which are mandatory to follow the temporal trend of human impact in these remote regions.