IWDG member and marine ecologist, Siún Ní Cheallaigh, began to develop a photo-identification catalogue for Risso’s dolphins in Ireland last summer. The initial funding to cover the cost of targeted photo-identification survey effort was granted by Galway Atlantaquaria’s funding for small conservation projects. Historical images of Risso’s dolphins going back as far as 2003 were sourced from the IWDG sightings database, IWDG volunteers with personal collections of Risso’s dolphin photographs, social media posts, anglers and sea safari operators.
This catalogue, which to date contains 113 individuals, is providing evidence for Risso’s dolphin site fidelity in Irish inshore waters. We have long known of ‘hotspots’ for this species in Ireland – places where they are more regularly observed than other parts of the coast. Some of these ‘hotspots’ include the Blasket Islands in Kerry, Dursey Island and Cape Clear in Cork, and the Saltee Islands in Wexford. The longest resighting history we have for any of our Risso’s dolphins so far is 17 years for an individual known as RDIRL#58 who was first observed at the Magharees in Kerry back in 2003 and resighted on multiple occasions around the Kerry coast up to 2020.
Left and Right side of RDIRL#58’s dorsal fin by Nick Massett, Blasket Islands
Kerry is the most well-represented county in the catalogue at the moment, with Cork following behind. The majority of individuals in the catalogue were photographed along the Kerry and Cork coasts, while a handful were taken from sightings at the Saltee Islands in Wexford and Rathlin Island in Antrim. This is not necessarily an indication that there are greater numbers of Risso’s dolphins in Kerry and Cork than anywhere else in Ireland. To date, most of the Risso’s dolphin photo-ID effort has been conducted in Kerry and Cork, where IWDG members like Nick Massett have devoted many years to photographing these animals, and where there is a much higher concentration of sea safari operators and members of the public out on the water taking photographs. There are likely many more Risso’s dolphins waiting to be catalogued elsewhere in Ireland, particularly in the southeast where there is also a large concentration of historical sightings.
While Siún has plans to undertake more targeted photo-ID survey effort this year, IWDG volunteers and members of the public submitting their sightings and photographs are the backbone of this catalogue. Without your help, we would not have gotten this far! If you would like to get involved, particularly if you live near any of these Risso’s dolphin ‘hotspots’ and spend a lot of time on the water, please get in touch with Siún by emailing irishrissosdolphinproject@gmail.com.
Similarly, if you have photographs of Risso’s dolphins in Ireland that you believe may not already be in the catalogue and you would like to share them, please send full resolution copies to the above email address.
If you would like to follow the progress of the project more closely, Siún provides regular updates on the project Instagram account @irishrissosdolphinproject
Cover image: Risso’s Dolphins by Willie Kavanagh, Wexford