A whale species never before recorded in Irish waters has been confirmed by the Irish Whale and Dolphin Group (IWDG).

The marine wildlife specimen reported at Glengarriff in West Cork on 1 May — which live-stranded before it was found dead the following day — is that of a dwarf sperm whale, IWDG strandings officer Stephanie Levesque said.

Video footage received of the whale was shared with international experts “who confirmed that in their opinion it was a dwarf sperm whale due to its taller dorsal fin and smaller back”.

Levesque acknowledged concerns over the distress of the animal in the supplied video but said that “there is nothing [anyone] could have done as it was thrashing violently on slippery, seaweed covered rocks … It is extremely important to understand, if you see a stranded animal thrashing violently in this way, as difficult as it is to watch, you must keep your distance.”

The 2.25-metre female whale was with calf when it died, and a post-mortem by Drs Jim Donovan and Mercedes Gomez-Parada at the Cork Regional Vet Lab could not confirm the cause of death.

Examining the carcass of the dwarf sperm whale, a 2.25m pregnant female | Credit: Simon Berrow

“Prey remains, including squid beaks, were found in its stomach which was recovered together with the whole intestine for further analysis,” Levesque added. “The skeleton will be prepared by the IWDG and donated to the National Museum of Ireland (Natural History) to be preserved by the State.”

Meanwhile, genetic testing of a skin sample was performed by Dr Eileen Dillane, a geneticist at UCC’s School of Biological, Earth and Environmental Sciences, who identified a 99% match with the genes of dwarf sperm whales from the Western North Atlantic.

The last known record of a dwarf sperm whale in this part of the world was a sighting off Cornwall in the UK in October 2011.

“Whether we might expect more strandings of this ‘warm water’ species in Ireland and the UK following the impacts of climate change remains to be seen, but it is very important to continue to report stranded cetaceans to the IWDG so we can monitor these trends into the future,” Levesque said.

This was the second animal to be examined under the new Deep-Diving and Rare Cetacean Investigation Programme (DDRIP) launched by the IWDG recently.