SOURCE: LiveScience

DATE: October 29, 2018

SNIP: A total of 80 deep-water whales have been found dead on the Atlantic coasts of Scotland and Ireland since early August — more than 10 times the usual number over that time in previous years.

Marine mammal scientists say the presence of the washed-up whales suggests an “unusual mortality event,” or UME, that could have killed up to 1,000 Cuvier’s beaked whales in the North Atlantic Ocean in recent months.

The cause of the whale deaths is unknown, but scientists fear they may be the result of warships using active sonar to hunt for enemy submarines, or naval anti-submarine exercises.

Around 26 of the carcasses were Cuvier’s beaked whales, a species that lives mainly in the deep ocean, while the rest were either Sowerby’s beaked or northern bottlenose whales.

Typically, just two or three dead beaked whales would wash up on the Irish coast each year.

Marine biologist Nicholas Davison, who heads the team of scientists that monitors marine mammal strandings in Scotland, said a total of 50 dead beaked whales had been found on the western coasts of the Scottish mainland and islands between mid-August and early October.

“It is absolutely unprecedented,” Davison told Live Science. “The average for a year is about two and a half, so you can see that we’ve got an exceptional event going on.”

Scientific research has shown that Cuvier’s beaked whales are sensitiveto the very loud sounds caused by anti-submarine sonar, which is used by warships hunting for enemy submarines and during naval anti-submarine exercises.

Scientists suspect theloud sonar sounds cause intense pain to beaked whales diving at extreme depths, so that they surface too quickly and die from decompression sickness. “The effect of navy sonar on beaked whales is fairly accepted, well-accepted, now,” Berrow said.