Occurrence and Diversity of Cyanotoxins and Retinoid Compounds in Antarctic Microbial Mats: Evidence From James Ross Island.

Antarctic ecosystems, though extreme, harbour diverse microbial communities dominated by cyanobacteria, which serve as crucial primary producers. Whilst the occurrence of cyanotoxins has been extensively studied in temperate climates, limited research has focused on their presence in polar regions. In this study, we investigated the distribution and diversity of cyanotoxins across various aquatic ecosystems on James Ross Island, Antarctica. Using targeted LC-MS/MS analysis, we detected microcystins, nodularin, cylindrospermopsin, and, for the first time in the Antarctic region, the neurotoxin saxitoxin, albeit at concentrations below quantifiable levels. Our findings also reveal the widespread presence of retinoids in microbial mats, with potential endocrine-disruptive properties, marking the first report of these metabolites in Antarctic ecosystems. This study highlights the ecological importance of cyanobacterial metabolites in Antarctic environments and raises concerns about their potential effects on local wildlife and water quality, particularly in the context of climate change. The findings underscore the need for continued monitoring and molecular studies to elucidate the sources and ecological roles of cyanotoxins in polar regions.