The silent invasion of anthropogenic plastic debris in an isolated protected area in Antarctica

Anthropogenic plastic debris has become an increasing environmental concern even in remote Antarctic ecosystems. This study investigated the spatial distribution, composition, and size structure of plastic debris in Cape Shirreff (ASPA 149), Livingston Island, Antarctica. Systematic visual surveys were conducted over 21 days during the austral summer of 2026 along the eastern and western coastal sectors using bidirectional transects. A total of 226 plastic debris items were recorded, with a higher concentration in the western sector (55.3%) compared to the eastern sector (44.7%). Plastic fragments were the dominant category (43.8%), followed by bottles, ropes, ALDFG (abandoned, lost or otherwise discarded fishing gear), and bottle caps. Macroplastics (>200 mm) predominated over mesoplastics (5-200 mm) in both sectors, and significant differences in debris size distribution were observed between coastal sectors (Wilcoxon rank-sum test, p < 0.05). Spatial analyses revealed a highly clustered distribution pattern (NNR = 0.159; p < 0.001), with accumulation hotspots concentrated mainly near the high tide line, with accumulation hotspots concentrated mainly near the high tide line. Plastic ingestion was recorded in skua regurgitations, and marine mammals were observed in proximity to ALDFG and other plastic debris, highlighting potential interactions between wildlife and anthropogenic waste. The results demonstrate that even protected Antarctic areas remain vulnerable to marine plastic pollution, reinforcing the need for long-term monitoring and integrated international mitigation strategies.