A preliminary note on the unprecedented strandings of 45 deep-diving odontocetes along the UK and Irish coast between January and April 2008

Between 13 January and 14 April 2008, 14 Cuvier’s beaked whales ( Ziphius cavirostris ), five Sowerby’s beaked whales ( Mesoplodon bidens ), four unidentified beaked whales and 22 long-finned pilot whales (Globicephala melas ) were reported stranded in Scotland, Ireland and Wales. Concerns that an unusual mortality event had taken place prompted further investigations although most carcasses were deemed to be too decomposed for necropsy. Preliminary findings are presented here and some potential causes of death considered. Although the event had some similarities with atypical mass stranding events linked in time and space to mid frequency sonars, there were also two important differences. First, the geographic range of the event was very wide and second, the strandings occurred over a prolonged period of about three months. Both of these factors could be related to the fact that the mortalities occurred offshore and the carcasses drifted ashore. The cause(s) of these high number of offshore mixed-species cetacean strandings during this period remains undetermined at this time.