What Left 33 Whales Dead on the Shores of Ireland?


33 pilot whales like this one were found dead on the shores of northwest Ireland earlier this week. Photo: Barney Moss under a Creative Commons License

Last Saturday, 33 pilot whales were found dead, beached on the northwest coast of Ireland. Mostly females and calves, the whales either died before washing ashore, or shortly thereafter. Now, scientists are looking to discover what caused the tragedy- and the British Royal Navy is one of the prime suspects.

According to Time, low-frequency sonar used by the Navy can damage whales' inner ears, impairing their ability to communicate, find food and care for their young. The Navy insists it is not to blame- their closest ship to the spot of the beaching was 50 nautical miles away (over 60 land miles). The whales could have fallen victim to any type of disease.But in a statement published on their website, the Irish Whale and Dolphin Group noted that they're not so sure:

There are many reasons we can speculate as to the cause of the stranding, but not to identify naval exercises as a POTENTIAL source of disturbance causing them to live mass strand, would be negligent. The IWDG have recorded an increase in strandings of deep diving species in Ireland and the UK to unprecedented levels and thus this is not an isolated case.

We feel rather than scapegoat the British Navy we are legitimately identifying potential impacts on deep-diving whale species. It is unlikely that a naval exercise needs to occur on the day of the strandings, but could easily impact on a pod of whales many days before the pod actually strands.

But while the Navy denies culpability and the IWDG hesitates to point fingers, evidence that the use of sonar at sea causes whale deaths is mounting. In August, Jaymi gave us a look into the effects of sonar on whales' brains. Earlier this year, filmmaker Volker Barth made the question not if ocean noise hurts whales, but how, in his film Sounds of the Sea.

Sadly, this is far from the largest mass beaching of whales in recent years. In March of last year, nearly 90 whales beached themselves on the shores of Australia. Just a few weeks ago, 80 whales were stranded on the shores of New Zealand. It is rare that many of the whales survive, as they need to remain wet to survive, and out of the water, can be crushed by their own body mass.

More on whale beachings and ocean noise:
Death Toll in Mysterious Mass Pilot Whale Beachings Hits 168
Top 5 Ways We Make Too Much Noise in the Ocean (and What That Means for Fish)
Lost In The Sound - New Sound Maps Show Ship Noise Blocking Whale Communication

Related Content on Treehugger.com