IDP: 2015 Results

2015 routes web

The 60+ sightings of 4 different cetacean species, the reappearance of “old friends” and the census of a new social unit of sperm whales have made the 2015 Ischia Dolphin Project (IDP) campaign full of great satisfaction and…. lots of work for our researchers and volunteers!

 

 

Between May and November 2015, the crew of Jean Gab – our lab vessel -  was engaged in 86 sea journeys in the waters between Ischia and Ventotene, navigating 4044 km and performing 662 hours of research and monitoring activities. During the campaign, 60 sightings of the following species were recorded: Sperm whale (Physeter macrocephalus), Risso’s dolphin (Grampus griseus), Striped dolphin (Stenella coeruleoalba) and Bottlenose dolphin (Tursiops truncatus), totalling 74 hours of observation time and 337 km of distance travelled.

social 2

With 22 sightings, the sperm whale ranks the first most sighted species in the 2015 campaign, with 9 newly photo-identified individuals: 4 immature males and 5 belonging to a new social unit (females with calves).

The discovery of a new social unit – defined as such by the presence of a small animal (8-9 metres) Diogene, a juvenile, and a female with two more adults (possibly females) – it is remarkable as the area is mainly inhabited by young males that use the rich waters of the Cuma Canyon as a feeding site.

 In 14 years of research (2003-2015) the members of only one social unit of sperm whale had been identified, sighted 5 times in 4 different years (2007, 2009, 2011 and 2013). The group composition has changed significantly in time, even if keeping a stable core. Two more social units had been identified before then in two consecutive years (2002, 2003), however during those encounters no photographic evidence of good quality was collected.

The presence of groups of female sperm whales with calves supports the theory that the waters of Cuma Canyon not only represent a site of feeding interest but also an area fit for reproduction and nursing behaviours. 

aletes dive

After 5 years of absence, the sperm whale Aletes, now close to sexual maturity, reappeared. He was first photo-identified together with juvenile individuals also known as bachelor groupsAletes was ‘recaptured’ (sighted again) alone, in the days following the sighting of the social unit. To recapture individuals and verify the constant growth of the total number of photo-identified animals – 80 individuals to date -  of a species that in the Mediterranean Sea is classified as ‘endangered’ in the Red List of the IUCN (International Union for the Conservation of Nature) is a hopeful sign of improvement of the species status, thanks also to the European ban on driftnet in 2002.

 

The 2015 campaign has also produced new data on a less known species, the Risso’s dolphin (Grampus griseus) classified by IUCN as ‘data deficient’ in the Mediterranean Sea. In Ischia waters this species has been sighted almost every year since 1999. Currently, there are 63 individuals in the catalogue (which means photo-identified): 47 adults, 9 sub-adults, and 7 juveniles. The photographic analysis of the 3 sightings in 2015 shows that 15 individuals were recaptured (amongst which young Gaudi and his family), confirming the species’ fidelity to the site, and 6 were sighted for the first time.

Modigliani sub

It was possible to trace the matriarchal line of Gaudi, who resulted being son of Vasari and grandson of Modigliani. Mother and grandmother were photo-identified for the first time in 2005 - when Vasari was still a calf – and were regularly ‘recaptured’ over the years, until today with their new family member. This species presents a physical characteristic that helps significantly its identification and the determination of the individuals’ age: a very thin skin layer that collects scars. A new born is in fact entirely dark grey and with time it gathers scratches that later become scars, and when it is adult or elderly it will be classified as ‘marbled’ or ‘white’, as its skin will be entirely white.

There wouldn’t be sightings, recaptures, acoustic registrations – there would not be Ischia Dolphin Project altogether – were it not for the dedication, passion and hard work of the researchers and volunteers that each year travel to Ischia from all over the world. Only this year, Jean Gab hosted 89 volunteers from Germany, Australia, USA, Ireland, Austria, Switzerland, Spain, France, Israel, Singapore, UK, Luxembourg, Canada and Italy.

We are extremely proud of these important results and we cannot wait to board the vessel again in May, and - finger crossed - we might see our friends Aletes, little Diogene or Gaudi with his mom and grandma...

For more information on the dates of 2016 campaing please visit Ischia Dolphin Project.

A BIG HEART-FELT THANK YOU TO ALL THE RESEARCHERS AND VOLUNTEERS OF ISCHIA DOLPHIN PROJECT!