Micro-litter waste in Deception Island (South Shetland Islands, Antarctica): A multi-matrix assessment

The Southern Ocean, one of Earth's most remote regions, is impacted by anthropogenic activities, with micro-litter waste posing a significant environmental concern. This study, conducted within the Deception Island caldera, presents one of the most comprehensive assessments of marine micro-litter in Antarctica to date. We provide novel data on stranded beach micro-litter and report the first Antarctic multi-matrix assessment encompassing beach sediments, ascidians, and surface waters. Micro-litter was widespread across the inner bay intertidal, with concentrations ranging from 0 to 11.85 items kg⁻¹ (mean 1.41 ± 2.46 items kg⁻¹). The highest levels were recorded near the BAA Decepción station (5.69 ± 5.39 items kg⁻¹), driven by the abundance of red alkyd paint fragments linked to station infrastructure, indicating that local, land-based human activities represent a major waste source. Fibres dominated all matrices, although their size and polymer composition varied, reflecting matrix-specific distribution. Beach sediments were mainly characterised by cellulose and nylon fibres (1–1.49 mm), ascidians predominantly contained smaller cellulose fibres (0.25–0.99 mm), and surface waters were dominated by larger polyester fibres (3.5 - >5 mm). Our results indicate dynamic exchanges among environmental compartments, with surface waters likely serving as the primary entry pathway for micro-litter, intertidal sediments functioning as transient fragmentation zones, and benthic organisms representing biological sinks for smaller and denser waste. This study provides essential baseline data for understanding micro-litter dynamics in Antarctic coastal environments. The results also underscore the urgent need for improved waste management of local activities, especially at research facilities.