Three marine turtle species regularly occur in the Mediterranean basin:
Leatherback turtle
lat. Dermochelys coriacea
The leatherback turtle has a worldwide distribution, and although nesting is confined to tropical and sub-tropical zones, at sea this species has the widest latitudinal distribution among marine turtles. The species occurs regularly in the Mediterranean, although it is not known to nest in the region. The individuals found in the Mediterranean are most likely to be of Atlantic origin, but the occurrence of this species in the Mediterranean is much lower than in the Atlantic.
Check out the map
This species has been noted in almost every area in the Mediterranean, but available data suggests that it mostly frequents specific areas such as the Tyrrhenian and Aegean Seas. It is present all year round, with no evidence of seasonality for longitudinal distribution and only possible seasonality for latitudinal distribution. Only large juveniles and adults frequent the basin, because small juveniles are restricted to tropical waters south to the Strait of Gibraltar.