Evaluation of fish biodiversity in the Beagle Channel (Tierra del Fuego-Argentina) using environmental DNA (eDNA) metabarcoding

Abstract

The fish biodiversity of the Beagle Channel is insufficiently assessed, poorly managed, and threatened by exotic species. Novel, rapid, and cost-effective DNA-based approaches are valuable for understanding fish communities and biomonitoring in remote areas. Here, we evaluate the potential of environmental DNA (eDNA) metabarcoding for assessing fish species composition by analyzing water samples from three sites along the Beagle Channel in the extreme south of Argentina. Fish biodiversity was estimated using high-throughput sequencing of 12S rRNA amplicons. First, a local reference database was generated, including 12S sequences of 48 spp. In total, 31 environmental sequences were recovered, belonging to 11 families, 15 genera, and 22 species. Six eDNA sequences did not match any species in our database. Multivariate analyses indicated that the relative species composition differed significantly among the sampled sites. However, the most abundant species detected were consistent with historical data on fish species recorded in the sites sampled. In conclusion, eDNA metabarcoding is sensitive, reliable, and suitable for studies on the presence and distribution of fish species in the area. We further strengthen the potential of eDNA metabarcoding as a biomonitoring tool.