Evidence of a striped dolphin (Stenella coeruleoalba) nursery zone in the waters of a terrestrial Nature 2000 Area “Mount Gerania” (Gulf of Corinth).

During the summer 2009 (July-August) a research study was conducted in order to define the habitat use and distribution of cetaceans inhabiting the Eastern portion of the Gulf of Corinth (GOC), a long and almost enclosed sea of Greece, Eastern Mediterranean. The GOC presents a small incidence of pleasure boats and, with a depth often over 900m, represents an area of high biodiversity, elected by small pelagic species. Surveys were carried out aboard a 12 m sailing vessel, covering an area of about 600 square km, in the waters of the Natura 2000 Area “Gerania Mount”. About 600 Km of route were surveyed. Three species were sighted: striped dolphin (Stenella coeruleoalba), common dolphin (Delphinus delphis), and Risso’s dolphin (Grampus griseus). The mean cetacean sighting frequency for the area resulted of 0,78 (sightings/monitored hours), while the encounter rate was 0,046 (sightings/monitored km). Striped dolphin was present in every sighting. Average school size for this species was of 12 individuals. A heavy presence of newborns and calves was recorded for this species: the 50% of groups had newborns and calves, the 10,7% had juveniles and adults, while the remaining 39,3% had just adults. The results of 2009 survey document the importance of this zone as nursery area for striped dolphin, possibly due to the low boat traffic and to the high availability of preys. Further studies on behaviour and habitat use would be useful to better understand the importance of this area for managing the species. To continue monitoring the species in the future would be also important because the area is developing fast in spite that is located in the waters of a terrestrial Natura 2000 Area.