A new scientific publication by Dimitris Margaritoulis and Alan F. Rees, members of ARCHELON's Scientific Committee, brings together for the first time all available records of the Leatherback sea turtle (Dermochelys coriacea) in Greek waters, spanning more than five decades (1968–2024).

The Leatherback is the largest sea turtle in the world and one of the most remarkable marine reptiles. It is a highly migratory species, travelling thousands of kilometres between its nesting and foraging grounds and occurring in oceans from the equator to sub-polar waters. Although its presence in the Mediterranean has been documented for decades, encounters remain exceptionally rare.

The new study combines records known up to 1984 (green dots on the map) with previously unpublished records collected after 1984 (red dots on the map). Altogether, the 57 records provide the most comprehensive picture to date of Leatherback occurrence in Greek waters.

The analysis shows that most sightings and records occurred in the Aegean Sea during the warmer months of the year, from May to November. Measured individuals had curved carapace lengths ranging from 1.23 to 1.80 metres, indicating that they were large juveniles or adults. These findings support the hypothesis that Leatherbacks occurring in Greece belong to a wider migratory population originating from nesting beaches in the western Atlantic, entering the Mediterranean to forage. However, it remains unknown whether and how many of these turtles survive to return to their natal nesting beaches to breed.

Unfortunately, the vast majority of recorded Leatherbacks were found entangled in fishing gear, mainly gillnets, while only a few individuals were released alive. This highlights that bycatch remains one of the most significant threats facing the species in the Mediterranean.

The study also demonstrates the long-term value of systematic data collection. Records gathered over several decades by researchers, port authorities, fishermen, organisations and members of the public have created a unique dataset that significantly improves our understanding of the ecology of one of the rarest sea turtle species visiting the Greek waters.

Read the scientific publication HERE

Learn what to do if you find an injured or dead sea turtle HERE