RT Journal Article SR Electronic T1 Newly developed ad hoc molecular assays show how eDNA can witness and anticipate the monk seal recolonization of central Mediterranean JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.02.13.431078 DO 10.1101/2021.02.13.431078 A1 Valsecchi, Elena A1 Coppola, Emanuele A1 Pires, Rosa A1 Parmegiani, Andrea A1 Casiraghi, Maurizio A1 Galli, Paolo A1 Bruno, Antonia YR 2021 UL http://biorxiv.org/content/early/2021/03/08/2021.02.13.431078.abstract AB The monk seal Monachus monachus is the most endangered pinniped worldwide and the only one found in the Mediterranean, where its distribution and abundance have suffered a drastic decline in the last few decades. Data on its status are scattered due to both its rarity and evasiveness, and records are biased towards occasional, mostly coastal, encounters. Nowadays molecular techniques allow us to detect and quantify minute amounts of DNA traces released in the environment (eDNA) by any organism. We present three qPCR-assays targeting the monk seal mitogenome. The assays were soundly tested on an extensive and diversified sample set (n=73), including positive controls from Madeira breeding population collected during the peak of abundance, and two opportunistic Mediterranean eDNA-sample collections (offshore/coastal) from on-going projects. Monk seal DNA was detected in 47.2% and 66.7% of the samples collected in the Tyrrhenian from a ferry platform (2018-2019) and in the Pelagie archipelago -Strait of Sicily- (2020) respectively, anticipating (up to 2 year) visual observations occurred subsequently in proximity of the sampled areas. In the Tyrrhenian, detection occurrence increased between 2018 and 2019. Monk seal DNA recoveries were commoner in night-time ferry-samples, suggesting nocturnal predatory activity in pelagic waters. The proposed technique provides a non-invasive and yet highly-sensitive tool for defining the monk seal actual distribution and home range, its recovery rate and pinpoint coastal/offshore localities where prioritizing conservation, research, citizen science and education initiatives.Competing Interest StatementThe authors have declared no competing interest.