Marine litter, microplastic pollution and organic additives assessments in polar areas through an opportunistic cruise ship-based approach

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.