Autopsies to be carried out on washed-up dolphins

Autopsies are being carried out on several dolphins that have washed up on beaches in the last month.

Two dolphins were recovered from a Kerry beach on January 28. Two more were recovered the previous day, one in Inverin, Co Galway and one in northern Donegal.

The carcasses were recovered by the Irish Whale and Dolphin Group (IWDG) and the autopsies are being carried out in the Cork Regional Veterinary Laboratory.

“The IWDG is expecting a lot of stranded dolphins to be found and reported over the next few weeks,” said Simon Berrow, chief science officer of the group.

While the cause of death, for the various mammals, has not yet been established, the recent recoveries are part of a growing trend.

In 2017, approximately 260 mammal carcasses were washed up on Irish shores — the highest number documented since records began more than 25 years ago by the IWDG.

“Up to and including 2010, IWDG never received more than 150 validated cetacean [whales, dolphins, and porpoises] stranding reports in any one year, but things started to change in 2011, when 163 strandings were validated and we thought that annual figures had reached a new high,” said Mick O’Connell, IWDG’s stranding co-ordinator.

“Little did we realise that 163 would soon become a ‘quiet’ year as annual figures continued to rise to a peak of 219 in 2013, with 212 in 2016, being the second highest annual total on record.

“By 31 August 2016, 156 cetacean had been received in that year but by the same date in 2017 IWDG had received 201 validated cetacean strandings — up a massive 30% compared to the previous two ‘record’ years.”

Last year also saw the stranding of two large fin whales, eight days apart. One was stranded on Arranmore Island, Co Donegal, on November 4, 2017, and measured approximately 20m in length. However, it was washed back out to sea before it could be recovered and examined.

A second whale, measuring 19m, was then washed ashore on November 12, in Co Sligo.

The IWDG said two strandings so close together was an unusual coincidence but were unable to establish if there was a connection between them.

There are only 41 recorded strandings of whales on the IWDG’s database, dating back to Bantry Bay in 1862. There are now on average 1.3 strandings a year.

Last November, IWDG in conjunction with Galway-Mayo Institute of Technology and UCC, published a study on marine debris in the guts of whales, dolphins, and porpoises. It was published in Environmental Pollution.

Marine debris was found in the stomachs and intestines of 8.5% of the dolphins and porpoises examined and microplastics were discovered in all