Russian embassy contacted as mystery surrounds death of two sperm whales off the Donegal coast

Two sperm whales have died and been found along two separate stretches of the Donegal coast just hours apart in rough seas this week.

The whales were reported washed up on the north coast by by-passers on the marine phone app called Observers created by the Ocean Research and Conservation Association of Ireland to log strandings.

The first stranded sperm whale was reported off Dungloe, Co Donegal, by a woman out walking on Wednesday and within hours received a second report of a 30-foot female sperm whale off Malin Head was logged by another passer-by.

Along with carrying out tests on the animals, the Irish ORCA organisation has written to the Russian Embassy in Ireland to enquire if their navy used military sonar off the north coast of Ireland in recent weeks.

The Russian navy was understood to be en route to Ireland to carry out military exercises in early February off the Cork coast, but they changed their plans after objections from Irish fishermen.

Sperm whales, which are among the largest of their species, can dive thousands of feet deep into the darkest regions of the ocean to hunt for squid.

They are among the species particularly sensitive to underwater acoustics like military sonar and can get the bends when they surface too quickly to get away from the noise and die.

Military sonar can cause damage to the hearing either through temporary threshold shifts or permanent damage which may lead to strandings.

ORCA Ireland Co-founder Emer Keaveney said the washing up of two dead whales so close together this week is a great cause for concern.

She said: “Two strandings are ringing alarm bells. They were discovered within four hours of each other. Certainly, their carcasses are at around the same stage of composition.

“They died far offshore and wind conditions and current and drift washed their carcasses ashore.

“A lot of carcasses will sink to the bottom so we only see a minimum of actual deaths when they wash ashore which is why it is concerning.

“They are a four-hour drive away from each other. One washed up just below Donegal Bay and the other on Malin Head."

The marine biologist said ORCA Ireland Marine Mammal Stranding responders have been on-site to further investigate the strandings, to take measurements and samples for genetic analysis.

“There is no other evidence of human interaction like entanglement.

“There is no other obvious reason for them to have stranded.”

For acoustic trauma, the inner ear has to be extracted within a few hours of death but lab tests on the stomach contents and the lungs can establish if the whales drowned

She said scientific literature points to military sonar causing the deaths of deep-diving species of sperm whales in the past.

She said: “We have an obligation on a European level to protect their kind of species.

“While it’s speculative that it’s noise pollution it cannot be ruled out.”

She appealed to the public to keep a watchful eye on the coastline especially in the north of the country as rough seas and high winds tend to wash bodies of dead marine creatures ashore in greater numbers.

The marine biologist said the double stranding, which also coincides with the stranding of a harbour porpoise this week, highlighted the need for underwater acoustic monitoring of Irish waters.

ORCA Ireland has recently begun a project called Smart Whale Sounds - which is using real-time acoustics and artificial intelligence to track the vocalizations of passing whales and to understand more about the soundscape of Irish waters.