A group of whales may have become stranded on beaches off the coast of Scotland after being frightened by major military activity in the area, animal welfare experts fear.
One long-finned pilot whale died while two others were returned to the water after becoming stuck on a beach in Portmahomack, in Easter Ross, north east Scotland, in the early hours of Wednesday morning.
A fourth whale was found on a beach on the opposite side of the bay yesterday but was also successfully rescued.
A major international exercise involving up to 30 ships and 75 aircraft from the Royal Navy, RAF, US military and other Nato forces has been taking place around the coast of Scotland.
Exercise Joint Warrior is Europe's largest military exercise and is held twice a year. It is taking place between 15 and 29 April around Scotland.
Marine mammal experts fear that the increased activity at sea and noise produced by the exercise may have frightened the normally deep sea mammals towards shallower coastal water.
The Ministry of Defence said that no underwater sonar had been used in the area of the strandings for more than a week and that it had taken extra steps to avoid disrupting any whales during the exercise.
A post-mortem of the dead whale, however, showed that it had been a healthy young adult male.
Further tests are being carried out on the animals brain and ears to look for telltale signs of damage caused by military sonar or excessive noise.
Stephen Marsh, operations manager at the British Divers Marine Life Rescue, said: “There has been a lot of activity in the area with aircraft and ships operating in the area.
“We don’t know what caused these whales to come ashore, but any activity out in their normal habitat can cause them to change their behaviour.
“It is possible that they have been frightened by the noise and moved out of the area where they normally are and become lost. We have no evidence of that yet and we don’t know if any sonar has been used.”
The use of underwater sonar has become increasingly controversial as scientists have found mounting evidence that it can cause damage to whales and dolphins hearing and interfere with their own ultrasound which they use to navigate and hunt.
Bubbles have also been found in the brains and other tissue of dead cetaceans that have also been linked to loud underwater sonar used by the military and deep sea oil exploration.
The latest strandings come two weeks after a sperm whale, another deep sea species, was found in shallow water near Oban on the west coast of Scotland.