Evaluation of micro-litter pollution in the Antarctic asteroid Odontaster validus Koehler, 1906 at Deception Island (South Shetland Islands)

Micro-litter (ML) pollution is increasingly being reported in Antarctic benthic ecosystems and the organisms inhabiting them. In this study, we assessed ML abundance and characteristics in the Antarctic asteroid Odontaster validus at Deception Island (South Shetland Islands), an area with significant human presence. Additionally, we considered the potential influence of local factors, including proximity to research stations and the bay entrance, as well as depth (5 and 15 m), on ML pollution. Approximately 63% of the specimens exhibited at least one item, all of which were fibers, with a mean abundance of 1.10 ± 1.05 items individual −1 and 0.77 ± 1.31 items g −1 WW. Spatial variability in ML abundance was detected, notably at 15 m depth, with specimens collected at BAE (3.15 ± 2.46 items g −1 WW), the sampling station nearest to research stations, exhibiting significantly higher abundances than those from sampling stations near the bay entrance. Our results are consistent with previous studies suggesting that Antarctic research stations may act as local ML sources, leading to higher ML abundances in benthic invertebrates inhabiting nearby areas. Although no significant differences were observed between sampling stations at 5 m depth or between depths, variations in ML abundances were also detected. Our results provide critical new insights into ML pollution in this key Antarctic asteroid species and how it is influenced by local factors. This study also supports the potential use of O. validus as a bioindicator of ML pollution in Antarctic benthic ecosystems, contributing to future monitoring and conservation efforts.