New Publication on Monk Seal!

Valsecchi, E., Tavecchia, G., Boldrocchi, G., Coppola, E., Ramella, D., Conte, L., Blasi, M., Bruno, A., Galli, P., 2023 Playing “hide and seek” with the Mediterranean monk seal: a citizen science dataset reveals its distribution from molecular traces (eDNA). Sci Rep 13, 2610. https://doi.org/10.1038/s41598-023-27835-6

Abstract: Animal conservation relies on assessing the distribution and habitat use of species, but for endangered/elusive animals this can prove difficult. The Monk Seal, Monachus monachus, is one of the world's most endangered species of pinniped, and the only one endemic to the Mediterranean Sea. During recent decades, direct observations have been few and scattered, making it difficult to determine its distribution away from the Aegean Sea (core distribution area of the post-decline relict population). This study relies on environmental DNA (eDNA) analysis to detect the presence of the Monk Seal in 135 samples collected in 120 locations of the central/western Mediterranean Sea, spanning about 1500 km longitudinally and 1000 km latitudinally.

Photo: www.mmc.gov

A recently described species-specific qPCR assay was used on marine-water samples, mostly collected during 2021 by a Citizen Science (CS) project. Positive detections occurred throughout the longitudinal range, including the westernmost surveyed area (Balearic archipelago). The distribution of the positive detections indicated six “hotspots”, mostly overlapping with historical Monk Seal sites, suggesting that habitat-specific characteristics play a fundamental role. We applied single-season occupancy models to correct for detection probability and to assess the importance of site-specific characteristics. The distance from small islets and protected (or access-restricted) areas was correlated negatively with the detection probability. This novel molecular approach, applied here for the first time in an extensive CS study, proved its potential as a tool for monitoring the distribution of this endangered/elusive species.

 

 

GEDA-i and "SPOT THE MONK" project!

Photo: P. Henry at IUCN

The increasing sightings of the Monk Seal Monachus monachus in Italy and central Mediterranean indicate a possible increase of the Atlantic (here) as well as Eastern Mediterranean populations. As part of the Med for Med project (more here), Prof E. Valsecchi has developed a novel technique to reveal Monk Seal traces of DNA in the environment (eDNA, here and here). “Spot the Monk” is the new initiative to assess Monk seals presence in the Central and Western Mediterranean. The first results are very promising (here). D.  Ramella, the GEDA-i and several collaborators are collecting samples around Mallorca from sites originally used by the seals. Stay tuned to know the results!