The secretive hunt for a suspected Russian submarine of the Scottish coast may have led to a spate of whale and dolphin deaths, conservationists have alleged.
Dozens of whales and dolphins have been washed up dead on the coasts of Scotland and Ireland in the past two months, and their deaths may be linked to military sonar used in the search, a protection group has said.
Warships, patrol planes and submarines are all believed to have joined the search, which continued into January.
Fifteen Cuvier’s beaked whales, which dive deeply and are known to be affected by sonar, are among the mammals washed up over the same period. Common dolphins, a minke whale, a sperm whale, pilot whales, a fin whale, and harbour porpoises have also washed up.
Whale and Dolphin Conservation (WDC), said the mass stranding “could be linked to a reported search by British navy warships for a suspected Russian submarine.”
It said: “Investigations following Britain’s largest mass dolphin stranding in 2008 concluded that the only realistic cause was military exercises taking place in the area at the time.”
However one Naval source said the link was “pretty tenuous” because the search had not involved active sonar.
He said: “We have not been pumping sound out into the ocean. This was a much broader game of cat and mouse using sonars that just listen.”
Two Royal Navy warships towing sonar sensors were joined by four maritime patrol planes from America, France and Canada.
Dr Andrew Brownlow, head of the Scottish Marine Animal Stranding Scheme, said WDC had asked the MoD for details of it operations to try to work out if there is a link.
He said: “They want to know what military activity was taking place in the area at the time. It is possible that these standings are linked to certain military activity. It is something we are looking at. But the animals were so badly decomposed we shall probably never know the answer,” he said.
Peter Evans, a whale expert at from the SeaWatch Foundation, said active sonar had been shown to affect whales and change their diving patterns, but it was very difficult to get evidence for individual cases.
He said: “Although people do tend to point the finger at sonar, and sometimes they might be right, you can’t be certain of what it is.”
Cuvier’s beaked whales have been found down the west coast between Scotland and Ireland including two on Mull, South Uist, Benbecula, Tiree and Kintyre.
Conor Ryan, of the Hebridean Whale and Dolphin Trust said in a typical year the trust would expect to see one or two of the whales stranded.
He said the numbers this year were “very unusual”, but there was no evidence the Navy was involved. The carcasses had been too badly decomposed for tests to be carried out.
A Royal Navy spokesman said: “The Royal Navy works very closely with organisations such as the Cetacean Stranding Information Programme on all matters of this nature.
“We have not been approached on this particular circumstance but we are ready to contribute fully to any investigation if required.”