Whales killed by the bends after warship sonar shock

A STARTLING theory has surfaced which suggests beaked whales get the bends when they surface rapidly – possibly after being startled by naval sonar.

The report could help scientists understand why the whales appear to be more vulnerable to the potentially harmful effects of sonar than other marine mammals. Together with other studies, the results may also help scientists and regulators think of how navies could adjust their sonar use during training to prevent beaked whale strandings and deaths.

"It provides more evidence that beaked whales being found dead in association with naval sonar activities are likely to be getting decompression sickness," said Robin Baird, a marine biologist and one of the report's authors. The study, published online this week in the journal Respiratory Physiology and Neurobiology, uses data gathered from three species in the beaked whale family. Two of the species, Cuvier's and Blainville's, were observed in Hawaii waters. The third, northern bottlenose whales, were studied off Nova Scotia, Canada.

In 2000, several whales washed ashore with bleeding around their brains during navy exercises in the Bahamas.