Sea turtles are ancient mariners that have inhabited our planet for over 100 million years. Sea turtles are air-breathing, egg laying reptiles with a long life span (they may live longer than 100 years). They are highly migratory species that spend almost all of their lives at sea. Only female adults come ashore to nest in the sand.
Three species of sea turtles frequent the Mediterranean. The Loggerhead turtle (Caretta caretta) and the Green turtle (Chelonia mydas) nest here, while the Leatherback turtle (Dermochelys coriacea) is an occasional visitor.
As listed on the IUCN Red List of Threatened Species the Global population of loggerhead turtles is classified as vulnerable1)iucnredlist.org and the Mediterranean sub-population as Least Concern, with the condition that conservation efforts are maintained. Mediterranean Green turtles are ranked as part of the global classification as Endangered2)iucnredlist.org, and the Leatherback turtle as globally Vulnerable3)iucnredlist.org.
Although sea turtles face natural threats ( e.g. natural predators), it is human activities that pose the greatest threats to their survival.
Loggerhead turtles reach sexual maturity between 16 to 28 (Casale et al., 2011) years and mate every two to three years in coastal waters. They then return to nest on the very same beach where they were hatched, called the “natal beach”. The sex of hatchlings is determined by the temperature of the sand (nest incubation temperature). Warmer temperatures result in a higher percentage of females and cooler temperatures in a higher percentage of males. Once a certain temperature is reached, at either scale, nests can produce solely females or solely males5)MTSG Regional Report 2018, as above..
Its range extends throughout tropical and sub-tropical seas around the world. In the Mediterranean green turtles are mainly found across the warmer eastern region, namely the Levantine basin (Turkey, Syria, Cyprus, Lebanon, Israel and Egypt), but are also known to have juvenile developmental grounds in marine habitats of Greece and Albania 7)https://www.archelon.gr/contents/ournews.php?mid=6&nid=1062 .
Leatherback turtles encountered in the Mediterranean originate from across the Atlantic Ocean. Leatherback encounters are reported in almost every Mediterranean country. They constitute a rare, but regular visitor to the region, where they enter presumably in search of food.
The leatherback turtle ranges in size between 130 – 183 cm and weighs between 300 – 500 kg (approx.). Currently there are no records of Leatherback turtles nesting within the Mediterranean.
All sea turtle species share common threats mostly stemming from human activity.
The above is by no means an exhaustive list of all threats that sea turtles encounter. It is an indicative list of main threats. For further information please contact: [email protected]
References [ + ]
|4.||↑||Hochscheid, S., Kaska, Y., Panagopoulou, A., (2018), Sea Turtles in the Mediterranean Region, MTSG Regional Report 2018|
|5.||↑||MTSG Regional Report 2018, as above.|
|6.||↑||MTSG Regional Report 2018 as above.|