For the third year running, together with Blue Marine Foundation, the IEF is supporting the Ionian Dolphin Project to continue their monitoring and research in Paxos, Anti Paxos and the Inner Ionian Archipelagos.
Ionian Dolphin Project have been gathering information from this region for over 30 years to ensure reliable data can better inform our understanding of the endangered common dolphin, as well as other dolphins found in the area, and the threats they face. They have identified and tracked dolphins of this region, observing injuries, recoveries and progress of individuals.
Recent updates from the team on one specific dolphin identified over this period describe the story of Spiti – a male Bottlenose dolphin who, having had his dorsal fin amputated, was believed to be dead…
Since 1991, the Ionian Dolphin Project is monitoring coastal dolphins in the Inner Ionian Sea Archipelago IISA, western Greece. A male bottlenose dolphin known as “Spiti”, first photo-identified in the IISA on April 2001, was observed in September 2003 with a very fresh and conspicuous wound, characterized by the almost complete amputation of its dorsal fin. Successive observations allowed us to witness the healing process of this severe injury. After encountering Spiti on yearly basis for a decade, we last saw Spiti in the IISA back in August 2010, which led us to the assumption that it had died.
Nevertheless, during surveys conducted in October 2016 and 2017, covering for the first time waters beyond the historical limits of our historical study area, we found it at about 100km north, in waters off Paxos and Antipaxos. On both occasions, Spiti looked healthy and was associated with 15-20 bottlenose dolphins interacting with a bottom trawler.
Spiti was seen again together with a group of 15+ dolphins following a bottom trawler between Paxos and mainland Greece on the 3rd October 2021 and more recently on the 8th May 2023, during surveys conducted with the support of Ionian Environmental Foundation / Blue Marine Foundation.
The cause behind the amputation of its dorsal fin remains unknown, but a plausible explanation may be entanglement with a long-line, or simply the cumulative effect of different injuries caused by intensive social interactions with other dolphins. Our observations indicate that this anatomic structure may not be of vital importance; nevertheless, the dorsal fin is known to provide stability while swimming and to assist in thermoregulation. Hence, its amputation may induce to decreased success when hunting prey, escaping predators or controlling body temperature.
Joan Gonzalvo, IDP Project Director
Observations such as these, together with discussions and interviews with the diving, sailing and fishing communities of the region, enable us to gain in-depth knowledge of the interface between dolphins and human marine activities with a view to ensuring the long term viability of these incredible marine mamals.