Marine litter, microplastic pollution and organic additives assessments in polar areas through an opportunistic...

This study presents findings from the opportunistic cruise, which performed microplastic and chemical contaminant sampling in surface waters, sediments, and ice in a sector of the western Arctic and the southwestern part of the Antarctic Peninsula. Microplastics were detected in 100 % of the samples. Floating microplastic densities (100-5000 μm) reached up to 314,251 items/km² in Antarctica and 63,593 items/km² in the Arctic. The smallest particles (100-300 μm) dominated in southwestern Antarctic Peninsula (97 %) where the fibers (80 %) and fragments (19 %) were the main components. In the eastern Arctic, the two size classes (100-300 μm and 300-1000 μm) were more evenly distributed (58 % and 40 % respectively) and polymer diversity. Sediment microplastic concentrations were higher in the Arctic (up to 470 items/kg) compared to southwestern Antarctic Peninsula (maximum 399 items/kg). OrganoPhosphate Esters and PhthAlate Esters were also measured for the first time in southwestern Antarctic Peninsula seawater (35.18 ± 18.31 ng/L and 72.68 ± 39.71 ng/L, respectively) and ice (50.44 ± 24.79 ng/L and 16.72 ± 11.46 ng/L, respectively). This study demonstrates the utility of cruise ship-based sampling for monitoring remote regions and it contributes critical baseline data for global microplastic assessments.