Integrating traditional and innovative monitoring approaches to monitor the marine biodiversity in the Tyrrhenian Sea (Mediterranean sea)

The Mediterranean Sea, a global biodiversity hotspot, is increasingly threatened by anthropogenic pressures, leading to a decline in marine biodiversity and ecosystem services. In response, effective monitoring and conservation strategies, including citizen science initiatives, are crucial for understanding and mitigating these impacts. This study presents the Marine Adventure for Research and Education (M.A.R.E.) initiative, which integrates public participation in marine biodiversity monitoring through visual surveys and environmental DNA (eDNA) sampling. Novel species-specific primers were developed to target key species, including Risso's dolphin, fin whale, basking shark, loggerhead sea turtle, and sperm whale. Over three months, approximately 100 participants contributed to the detection of endangered marine species, including the loggerhead sea turtle, striped dolphin, fin whale, and basking shark, in the Tyrrhenian Sea. Thus, eDNA analysis proved to be a highly sensitive and non-invasive method for detecting a wide range of species, complementing traditional visual surveys. As a matter of fact, the second most detected species with molecular analyses was the Risso's dolphin, an elusive species previously underreported in the region. Thus, this study suggests that eDNA technique might be considered a promising technique to monitor the Risso's dolphin distribution in the Mediterranean Sea.