Concern at High Number of Stranded Cuvier's Beaked Whales in December

5th Jan 2015

Update: 6 January 2015:

While there have (thankfully) been no further confirmed reports of stranded Cuvier's beaked whales in Ireland, the number of strandings for this species in Scotland has also risen to five, bringing the current combined total recorded to ten in only three weeks, a shockingly high figure for this species. Again, we have no idea as to the actual number of dead animals as we have no idea as to how many carcasses were not washed ashore or were stranded and went unrecorded. Further information on the Scottish strandings can be found at: http://www.whaledolphintrust.co.uk/news_article.asp?news_id=411

Update: 28 December 2014:

Confirmation has now been received of a fifth stranded Cuvier's beaked whale. This 6m male washed ashore dead and in poor condition near Clifden, Co. Galway on Christmas Day. Reports indicate that it was seen three days earlier floating dead in the bay. This number of stranded beaked whales occurring in such a short timescale has never been recorded in Ireland before and is a source of ongoing concern and frustration at not being able to establish the cause of this unusual mortality event to see if it could have been avoided or, indeed, prevented from happening again to this poorly understood species.

Occasionally, a live stranding of a sick/injured cetacean attracts a lot of attention and perhaps recriminations about what has or hasn't been done to 'save' the animal concerned from a welfare point of view. Unusual strandings such as the Cuvier's beaked whales this December however, often seem to pass by relatively unheeded despite the fact that they may have far greater implications. Imagine the furore if there had been five separate live strandings of beaked whales over the last few weeks. This is why the IWDG maintains a cetacean stranding database - raise awareness (especially of unusual events) in the hope that more people will start asking questions. If there's enough interest to ask questions, then we will start getting answers and work towards preventing cetacean mortality where possible. 

Original Story 23 December 2014:

IWDG are concerned that we have had four separate strandings of Cuvier’s Beaked Whales Ziphius cavirostris reported to us between 11 and 21 December. These were at Elly Beach, Mullet Peninsula, Co. Mayo (11 Dec), Portballintrae, Co. Antrim (14 Dec), Glencolumcille, Co. Donegal (18 Dec) and Kilshannig, Co. Kerry (21 Dec). This is a disturbing number of strandings for this species over such a short period of time as there are only 52 records of stranded Cuvier’s on the IWDG Strandings Database since 1904. In 2008, there were four strandings of this species in Ireland spread throughout the year and in 2013 there were three records between 7 January and 17 March. Three of the animals stranded recently were washed ashore in similar stages of decomposition but the 5m female washed ashore at Portballintrae, Co. Antrim was in very fresh condition. Of the four strandings, this one would have been the most suitable for investigation into cause of death but unfortunately no funding was available for post mortem examination. During the last few weeks two Cuviers strandings have also been recorded by the Scottish Marine Stranding Scheme in the Western Isles of Scotland, further increasing concerns of an unusual mortality event.

 

Cuvier’s beaked whales are relatively abundant in comparison with other beaked whale species and are found in most non-polar oceans. They are inconspicuous and rarely observed live in Irish waters, most often in deep water over submarine canyons beyond the continental shelf. There have been several documented cases of Cuvier’s beaked whales which suggest a connection between anthropogenic noise and mass strandings of this species (eg Greece 1996, Bahamas 2000, Madeira 2000, Canaries 2002) but without proper post mortem examination, ideally of freshly dead animals, we will never know for sure if the recent strandings are connected, avoidable or due to some natural phenomena. It is worth noting that the number of strandings recorded is a minimum as we have no idea how many other carcasses have either sank at sea or were washed ashore and not recorded.

 

Mick O’Connell,

IWDG Strandings Officer