Unusual mortalities of Kerry bottlenose UPDATE

28th Jul 2009 UPDATE 28 July 2009

There have been no more reports of dead bottlenose dolphins in Tralee Bay. Kerry Co. Co. received a report yesterday (27 July) of a dead dolphin at Banna Strand but it was washed out by the tide before it could be examined.

Conor Ryan and Vanessa Klotzer of the Shannon Dolphin and Wildlife Foundation and the IWDG have examined the three dorsal fins of the animals which we carried out post-mortem examinations on and seven dolphins with well-marked fins extracted from footage/images taken during the mass stranding by James McCarthy of DIGIMAC of Fenit and we cannot find any matches to the Shannon Estuary or to the Irish Coastal Bottlenose Dolphin catalogue.

Anneli Englund at CMRC also looked through the UCC Bottlenose dolphin catalogues from the Shannon Estuary and elsewhere in Ireland and while the dolphin we examined on the 13 July at Spa may be possibly a match to the Shannon Estuary, nobody is prepared to call it so it is probably unlikely.

It seems that these dolphins were not from the Shannon Estuary and surprisingly also hadn't been reported anywhere despite some of them being well-marked. Maybe they were offshore dolphins unfamiliar with land and thus more likely to live strand !!!

This event does highlight the need for a contingency plan, including the training for vets in cetacean post-mortem examination to enable the NPWS to respond to a potential epizootic or other unusual stranding event more effectively.

UPDATE 21 July 2009

A further report of a dead dolphin at Tralee Golf Club at Fenit on the morning of the 20 July was followed by a report of two bottlenose dolphin washed up at Camp on the south side of Tralee bay. This news was not unexpected but was still distessing as we suspect most, if not all, the bottlenose dolphins involved in the mass live stranding on 10 July will have died and some will be found over the coming weeks. The dolphin at Tralee Golf Club was a decomposed common dolphin, bringing the total to four bottlenose dolphins recorded dead in Tralee Bay since the live mass stranding.


Kerry County Council vet Paddy Fenton asked for assistance with the post-mortems from Limerick Regional Veterinary Lab as if a virus is responsible then it is neccessary to carry out a lot of tissue sampling and histology to isolate the cause. Alan Johnson joined Paddy, Simon Berrow and Mairead Moore on the beach at Camp, but both dolphins were not fresh and only limited sampling could be carried out and cause of death not possible to determine. Surprisingly both dolphins were immature males, consistent with the dolphin examined in Spa on 13 July!

We are still trying to establish whether these are Shannon dolphins. Both dolphins at Camp had marks on their dorsal fins and the IWDG were provided with video footage and images of the mass stranding by James McCarthy of DigiMac in Fenit. This footage shows at least 5 or 6 well marked individuals so we hope to be able to clarify this soon. Skin samples for genetic analysis were taken and could be used to identify Shannon dolphins as some alleles are thought to be unique to the Shannon population.

So the story unfolds and the mystery deepens. Is the cause of death selecting immature males? Was the group that mass stranded a group of immature animals, a bachelor herd? We do not know, but if more animals are found then we might be able to take the story a little further. Many thanks to eveybody who has contributed so far.

UPDATE 17 July 2009

Following great detective work by Mick O'Connell a video of the live stranding has been tracked down. James mcCarthy of DigiMack in Fenit has video of of 17 bottlenose dolphins stranding on 10 July in Spa. Locals re-floated all but one which was subsequently post-mortemed on 13 July.

This was a remarkable achievement and, if these were Shannon dolphins, then this action has made a massive difference to a small and