Leatherback Turtle in waters of Ischia

Tartaruga liutoPRESS RELEASE - NAPLES, 04/08/2018 - Oceanomare Delphis Onlus and Stazione Zoologica Anton Dohrn together for the knowledge and conservation of the biodiversity of our Sea.

Last 25th June, the researchers of Oceanomare Delphis Onlus (ODO) within Ischia Dolphin Project – for the monitoring and conservation of cetaceans – encountered a rare Leatherback turtle (Dermochelys coriacea), immediately warning the Marine Turtle Research Center of Stazione Zoologica Anton Dohrn. The event occurred with great timing, as the two organisations have started a scientific collaboration for the realisation of joined-up research, education and awareness activities to the benefit of the conservation of the marine ecosystem, with a special focus on great vertebrates. 

The sighting of the leatherback turtle occurred 4 miles off Ischia Island, at a depth of between 400 and 600 meters, corresponding to the area of the underwater Cuma Canyon, in the proximity of Area D of the Marine Protected Area of Ischia, Procida and Vivara.
The turtle was an adult, about 2mt of length, and it surfaced for about 15 minutes, allowing ODO researchers to 'capture' it photographically and thus gather important information to share with the Marine Turtle Research Center of Anton Dohrn. As for cetaceans also for turtles, it is possible to do photo-identification analysis: whereas for dolphins and whales the shape of the fin, scars and notches are the features to look for, for the leatherback turtle, a distinctive and individual-specific feature is the shape of the pink spot on her head.

Due to the globally-scaled impact of human activities, the leatherback turtle is listed as Vulnerable with decreasing population trends in the IUCN Red List of Threatened Species. It is the biggest of all 7 sea turtle species and is distributed circumglobally, with nesting sites on tropical sandy beaches and foraging ranges that extend into temperate and sub-polar latitudes. It has thus the widest range among sea turtles and reptiles in general, while It is the most pelagic turtle and feeds mainly on jellyfish and other pelagic invertebrates. During their extensive foraging movements, leatherbacks also enter the Mediterranean, but they are not known to nest there. Recent research using genetic markers has revealed that leatherbacks in the Mediterranean originate from southwestern Atlantic Regions like French Guiana or Trinidad.

Sandra Hochsheid, Head of the Marine Turtle Research Center of Stazione Zoologica Anton Dohrn – affirms: "Within the Mediterranean leatherback turtles are not distributed evenly but occur in higher numbers in the Western basin, although they arrive also to the far east such as Israel and Egypt. Of 411 specimens reported between 1981 and 2000, 152 were from Italy. Unfortunately, on its Mediterranean cruise the leatherback turtle, as the other sea turtle species, is threatened by human activities, mostly fisheries, as well as the ever-increasing pollution through plastic debris. Indeed, one specimen was found in Gaeta in 2007 had the stomach and intestine full of plastic bags, which the animal had probably mistaken for jellyfish, its preferred food."

"The presence of plastic in our sea represents one of the main threats also for the populations of cetaceans using these waters as feeding and reproduction areas, " continues Barbara Mussi, President of Oceanomare Delphis Onlus. "The waters off Ischia, Ventotene and Capri are since 1991 the study area of Ischia Dolphin Project, within which we monitor, besides cetaceans – target species of our project –, also sea turtles as additional indicators of the conservation and biodiversity status of the marine ecosystem. As a matter of fact, since the beginning of this year's campaign, our researchers have carried out 15 sightings of turtles, 14 were loggerhead turtles (Caretta caretta) and the last one was a Leatherback."

The collaboration among these two organisation is thus based on the common mission of increasing and promoting scientific knowledge on great vertebrates of our Sea to the benefit of their conservation and awareness of the public.