A total of 145 records of stranded cetaceans were reported to the IWDG during 2006 – which is the highest annual total since records began.
A list of all stranding records from the IWDG have recently been submitted to the Irish Naturalists’ Journal for publication. At least 15 species were identified including the first sei whale record since 1914. As in previous years the two most frequently recorded species were common dolphin followed by harbour porpoise.
The most dramatic increase in records was for striped dolphin with 16 records including a mass stranding of 14 individuals (the first time more than three individuals of this species have been recorded stranding together). There have been 101 stranding records of striped dolphin since 1901 with a mean of around 4 records per annum. The previous highest total was nine records in 1991.
The number of stranded Northern bottlenose whales was also higher than previously reported. During 2006 there were four records of this species, the same number reported over the last decade. Two Sowerby’s beaked whales were reported during 2006. Of the 10 records of this species since 1864, two each were in 2004 and 2006.
The increase in stranding records is attributed to an increase in awareness and interest in biological recording. However the increase in the proportion of striped dolphin strandings may be significant and could reflect an increase in seawater temperatures in Irish waters. The increase in strandings of deep diving species such as Northern bottlenose and beaked whales may also be of significance and it will be interesting to see if this trend continues in future years.
A full list of stranding records will be published in the Irish Naturalists’ Journal.
Mick O’Connell and Simon Berrow