As numbers have risen, there is now serious concern as to what has caused the unprecedented increase in beaked and pilot whale strandings on the Irish and UK coast. The principle species involved are Cuvier’s beaked whales Ziphius cavirostris, pilot whales Globicephala melas and Sowerby’s beaked whales Mesoplodon bidens.
Between 1 January and 17 April 2008, IWDG have received reports of 12 separate pilot whale strandings around the Irish coastline. This compares to an average of 2.6 separate pilot whale strandings for the same period annually, during the years 2003 to 2007 (inclusive). We have also received reports of 5 strandings of either Cuvier’s beaked whales (2) or unidentified beaked whales (3). The average number of stranding incidents involving these species (Cuvier’s, Sowerby’s, True’s, Gervais’ or unidentified beaked whales) in the years 2003 to 2007 was 0.6 during the same period annually.
In effect what we are seeing so far this year is that beaked whale strandings are running at about 8.3 times average and pilot whale strandings are about 4.6 times average. Since February, the west coast of Scotland has also seen a significant increase in strandings of these species with a minimum of 11 Cuvier’s beaked whales, 3 Sowerby’s beaked whales and 10 pilot whales recorded so far. In the majority of cases, the animals died at sea and were washed ashore in an advanced state of decomposition which raises the question of how many others stranded in inaccessible locations or did not wash ashore at all.
In previous incidents involving mass strandings of beaked whales, concerns have been raised over the effects of naval sonar during military exercises. At present, we have no evidence of the cause of death of these cetaceans and it is curious that pilot whales are also involved. It is ironic that UK/NATO naval manoeuvres (Exercise Joint Warrior 081) are to begin off the coast of western Scotland this week and a press release from the Whale and Dolphin Conservation Society (endorsed by IWDG and the Hebridean Whale and Dolphin Trust) is now available on our downloads page at;
http://www.iwdg.ie/downloads.asp?id=26