Stranded beach debris in the West Antarctic Peninsula: Quantification and distribution of marine litter.

Marine debris, particularly plastics, is a growing threat to global marine ecosystems, including remote regions like the Southern Ocean. This study presents one of the most extensive surveys of beached marine debris along the West Antarctic Peninsula, covering 31 beaches from 62° S to 67° S, the widest latitudinal range in Antarctica. Our results reveal the prevalence of stranded debris, with plastics as the main pollutant. Higher debris densities were observed near research stations, with Esperanza Bay (9.26·10-1 items m-2) and Cierva Cove (5.56·10-2 items m-2) beaches exhibiting significant pollution levels. We observed a concentration of debris at lower latitudes, particularly around the South Shetland Islands, due to intense anthropogenic activity. Furthermore, we compared the plastic litter between two islands with distinct geomorphology: Livingston Island, an open system influenced by oceanic currents, and Deception Island volcanic cone, an enclosed system sheltered from such dynamics. These revealed that Livingston Island showed higher densities of plastics related to food usage, which were larger, heavier, and predominantly composed of polyester, mostly drifting plastics associated with maritime sources. In contrast, the volcanic cone of Deception Island, sheltered from the ocean, predominantly contained plastics with an undefined use, which were smaller, lighter, and primarily made of polystyrene and polyethylene, suggesting debris of local origin. The study highlights the influence of both human activities and ocean dynamics on debris distribution, underscoring the need for improved waste management and international regulations. These findings provide a baseline for future research and policy development to preserve Antarctica's fragile ecosystems.