Environmental DNA as a Tool for the Preliminary Assessment of Vertebrate Biodiversity: A Case Study from Sicilian Freshwater Ecosystems

Freshwater ecosystems are rapidly losing biodiversity due to anthropogenic and environmental pressures. Considering that many species remain unknown, these systems represent an invaluable reservoir of biodiversity. For this reason, a prompt biodiversity census becomes essential. Environmental DNA (eDNA) has the potential to provide a faster and non-invasive alternative to traditional methods for biodiversity monitoring, conservation, and management. This study used eDNA to provide a preliminary snapshot of vertebrates in two Sicilian lakes: Lake Rosamarina and Lake Garcia. eDNA analyses identified four classes of vertebrates, 14 orders, and 16 families, with notable taxonomic differences between the two lakes. The analysis revealed the presence of several non-native and potentially invasive species, including fish (<i>Cyprinus carpio</i>, <i>Micropterus salmoides</i>, <i>Perca fluviatilis</i>, <i>Carassius auratus</i>, and <i>Ameiurus melas</i>), as well as the amphibian <i>Xenopus laevis</i> and the terrestrial mammal <i>Myocastor coypus</i>. The presence of these species, known for their ecological impact on native communities, highlights the potential of eDNA analysis as a powerful tool for the early detection and preventive biomonitoring of biological invasions. These results provide an initial assessment of vertebrate biodiversity in these sites, demonstrating how eDNA can serve as an effective method for biodiversity evaluation and monitoring.