Common dolphins around the island of Ischia, Italy
The 2002-2010 Conservation Action Plan for the World's Cetaceans by IUCN highlighted the importance of the waters surrounding the Italian island of Ischia as a critical habitat for common dolphins. The presence of common dolphins has been consistently documented by Delphis since 1997, and this is the only long-term study of common dolphins in Italian waters. The animals are mostly sighted in the summer over the submarine canyon of Cuma, a highly productive marine area characterized by significant pelagic biodiversity and multi-species associations.
The canyon of Cuma NW of the island of Ischia.
Between 1997 and 2006, a total of 90 common dolphins were photoidentified around Ischia. Of these, 52 were re-sighted over the study period, suggesting a high degree of site fidelity.
Breeding is often observed, and calves are always present, suggesting that in the summer this area may be an important breeding and/or nursing ground. Common dolphins are often seen in association with striped dolphins, particularly during surface feeding targeting shoaling prey.
A short-beaked common dolphin photographed around Ischia. Photo © Delphis mdc.
The Atlantic saury (Scomberesox saurus), a seasonal fish that is highly valued on local markets, is a typical prey of common dolphins around Ischia. Local fishermen claim that cooperative fishing may occur, with fishermen taking advantage of fish aggregations that are actively schooled by common dolphins. In the past, fish rewards were offered to the dolphins in reciprocation.
Based on interviews conducted locally, the area is exposed to overfishing and a variety of anthropogeinc impacts that may threaten common dolphins and other marine species. The creation of a Marine Protected Area called 'Regno di Nettuno', which includes the canyon of Cuma, is a critical measure to protect common dolphins.
Cetacean Alliance investigators:
For more information, see:
Mussi B., Miragliuolo A. 2003. I cetacei della costa nord occidentale dell’isola d’Ischia (Canyon di Cuma). Pp. 213-232 In: M.C. Gambi, M. De Lauro & F. Jannuzzi (Eds.), Ambiente marino e costiero e territorio delle isole Flegree (Ischia, Procida e Vivara - Golfo di Napoli): risultati di uno studio multidisciplinare. Memorie dell'Accademia di Scienze Fisiche e Matematiche, Società Italiana di Scienze, Lettere e Arti in Napoli. Liguori Editore, Napoli. (1.5 Mb)
Bearzi G., Reeves R.R., Notarbartolo di Sciara G., Politi E., Canadas A., Frantzis A., Mussi B. 2003. Ecology, status and conservation of short-beaked common dolphins (Delphinus delphis) in the Mediterranean Sea. Mammal Review 33(3):224-252. (345 K)