Following numerous reports of large concentrations of basking sharks from County Cork to County Galway the Irish Basking Shark Study Group successfully tagged ten sharks off County Kerry. Basking sharks occur each year all around the Irish coast – one of the few countries in the world where this phenomenon occurs, providing amazing opportunities to observe these magnificent creatures but also to study their behaviour.
Over two days at the start of April, ten sharks were tagged with individually numbered coloured tags. “we use green tags in County Kerry, so even if only the tag is reported elsewhere we know which county the shark was tagged” said Dr Simon Berrow of the IBSSG.
Since 2008 we have deployed over 350 of these tags from Cork to Donegal and we are collecting invaluable information on movements, site fidelity and abundance estimates.
The tagging trip to west Kerry was the first of the year. A team of three scientists including Enda McKeogh, Paddy O’Dwyer and Róisín Pinfield joined local boatman Nick Massett out of Ventry on the Dingle peninsula. The Blasket Islands are an amazing place for a wide range of marine wildlife and during the tagging we also recorded three minke whales, dozens of common dolphins and small numbers of harbour porpoise. Around 20-30 sharks were observed on the surface but they proved quite difficult to approach for tagging. Team Leader Enda McKeogh said “This was my first time leading a tagging trip and we found it difficult to deploy tags. The sharks varied in size ranging from under 6m to 8m for the most part but we did come across a monster at around 9m long off Slea Head”.
In addition to tagging the team collected slime samples from each shark for extracting DNA for population and genetic studies. “We have pioneered the use of shark slime for genetic studies and early analysis suggests basking sharks in county Kerry may be genetically different from other basking sharks in Ireland. Only by collecting more samples can we be sure and if they are it really throws up so many new questions about why this is the case and where are these sharks coming from.”
With the drop in temperature and increase in wind strength this period of shark sightings on the surface is likely to be over but we look forward to more tagging and sampling during the next calm period. Please send all shark sightings to www.baskingshark.ieor www.iwdg.ie.