Use of benthic nematodes in assessing ecological quality in anthropogenic impacted areas in coastal Antarctica

Human influence on Antarctic marine ecosystems is a growing concern, despite limited available information. In this study, we assessed the effects of anthropogenic pollution on free-living nematode community structure around Casey Station, East Antarctica. Sediment samples were collected from six locations impacted by human activities-Wharf, Wilkes, Brown Bay Inner, Brown Bay Middle, Brown Bay Outer, and Shannon-and four reference locations: three in O'Brien Bay and McGrady Cove. Nematode communities differed significantly among locations, correlating with higher pollutant concentrations (metals and persistent organic pollutants) at impacted locations and with finer sediments with higher organic content. The reduction of taxonomic, diversity, and functional parameters, as well as the dominance of opportunistic genera and the low ecological quality status scores in the impacted locations, suggests an environment stressed by organic enrichment, possibly linked to anthropogenic activities. The results reinforce the value of marine nematodes as bioindicators and contribute to the understanding of the impact of pollution on the biodiversity of these organisms in Antarctic coastal ecosystems.