(The Daily Mail)
Sonar soundwaves 'drive terrified whales to their death onshore'
By David Derbyshire
Last updated at 3:56 AM on 15th March 2011
Soundwaves from underwater military sonar are far more distressing for whales than was previously thought and drives some terrified creatures to their death onshore, a new study has show.
Scientist say beaked whales may also react with terror to noise from offshore wind turbines and oil and gas exploration.
Two years ago Europe's largest military exercise held in Scottish waters was at the centre of a row when conservationists claimed two whales had been harmed by sonar.
Distressing: Researchers have found that sonar, wind turbines and gas and oil drilling can drive some beaked whales to come to the shore (file picture)
The new study by researchers at St Andrews University looked at the effects of sounds on the behaviour of beaked whales in the Bahamas.
Researchers played sonar sounds to whales in the wild and recorded their reactions using electronic tags attached to their bodies.
Prof Ian Boyd, who led the study, said: 'We showed that the animals reacted to the sonar sound at much lower levels than had previously been assumed to be the case.
'We stopped exposing the animals to the sounds before there were any dangerous effects but it was clear that these whales moved quickly out of the way the sonars. We now think that, in some unusual circumstances, they are just unable to get out of the way and this ends up with the animals stranding and dying.
'There was always a strong association between the death of these strange, little-known animals and naval exercises. We have now shown that this may well be the case.'
However, the researchers warned that other sounds could cause problems.
'There is a tendency to blame the Navy for every stranding event and that is ridiculous,' he said.
'We are now beginning to understand that some species of whales and dolphins appear to be much more robust to disturbance by sound than others.
'We also found that beaked whales responded in the same way to sounds other than sonars, included the calls of killer whales. It appears that they just don't like unusual sounds but the way in which sonars are used to hunt for submarines may mean that the whales are more vulnerable to that type of sound.'
Danger: Scientists say whales also react in terror to the noise made by offshore wind farms
Beaked whales are mysterious creatures and extraordinarily difficult to study.
Despite being about the size of a rhinoceros few sailors have seen a beaked whale.
The timid creatures avoid the shallows and dive away from ships or passing aircraft.
Prof Boyd and his team said their findings, published in the journal PLoS One, had serious implications.
'I can see some quite robust advice being provided based upon our results that can help naval activity avoid the problem of causing beaked whales to strand, but I am also worried that the general levels of sound that humans make in the ocean from all sorts of sources like ships, oil and gas exploration and renewable energy may be a much more serious problem for beaked whales and some other sensitive species,' he said.
'Perhaps the most significant result from our experiments is the extreme sensitivity of these animals to disturbance.'
The latest NATO military exercise, Joint Warrior, is due to take place later this month off the west coast of Scotland.
Two year ago the Hebridean Whale and Dolphin Trust monitored two minke whales within an hour displaying unusual and worrying behaviour.
At the same time they heard military sonar. It has long been suspected that the untimely death of some beaked whales during the time of naval anti-submarine exercises has been caused by the sonars used to detect submarines.
Places:
Scotland,
The Bahamas,
Europe
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