Unravelling Antarctic Coastal Waters: Exploring Marine Biodiversity and Detecting Potential Invasive Species via eDNA Metabarcoding in South Bay, Doumer Island

Abstract

The average global temperature has increased significantly in recent decades, with no exception for the polar regions, including the Arctic and Antarctica. In Antarctica, this climate change directly affects the Antarctic Peninsula, which experienced significant temperature increases between 1979 and 2019. Doumer Island, located in the Palmer Archipelago of the Western Antarctic Peninsula, has become an important location both as an Antarctic Specially Protected Area 146 and as a witness to the future changing ecosystem, since South Bay of Doumer Island is recognized as one of the global warming hotspots. The use of eDNA metabarcoding has been shown to be a successful approach in accurately capturing the diversity of marine ecosystems. In this study, eDNA analysis was utilized to monitor biodiversity and detect non-native species in South Bay, Doumer Island. Seawater samples were collected from four sampling stations near the Chilean Antarctic scientific base Yelcho (64.9° S, 63.6° W) aboard a boat. We present additional data on the coastal pelagic community for the first time, expanding the biodiversity records of western coastal Antarctica. This includes newly discovered species as well as potential non-native species in South Bay near the Yelcho base. Our results indicate that eDNA analysis is an effective method for assessing marine biodiversity and detecting invasive species. However, the technique has some limitations that need to be addressed. The reference DNA databases for Antarctic species are incomplete, which impedes accurate species identification from eDNA samples. Consequently, further research is necessary to enhance these databases and improve taxonomic descriptions.