Thursday, June 07, 2007

Naval exercise may mean whale strandings

Left: A beaked whale beached in the Bahamas was one of 16 nearly simultaneous groundings following antisubmarine exercises using standard tactical sonars. The timing raised suspicions that the marine mammals had been disoriented by "barotrauma" -- pressure injuries to sensitive ear and brain tissues caused by sound waves. Once beached and deprived of the buoyancy of the water, a whale's weight can crush its own internal organs, leading to a painful death.

ANCHORAGE, Alaska — Mass strandings of beaked whales could occur in Australia this month as a result of naval midfrequency sonar being used in a joint military exercise, the International Whaling Commission warns in a report.

Environmentalists are calling for the Navy to stop its use of the submarine-hunting sonar, saying its effects on cetaceans — whales, dolphins and porpoises — are devastating.

“The reality is the strandings are only the tip of the iceberg,” said Marsha Green of the Ocean Mammal Institute. “Most of the animals that are injured are going to die and sink to the bottom.”

Naval sonar has been the subject of intense debate in recent years.

Environmentalists claim it can result in hearing loss and tissue damage. They say it can also alter diving habits as whales try to escape the noise. For a deep-diving species like the beaked whale, rapid surfacing can result in a fatal case of the bends, they say.

The biennial exercise, Talisman Saber, this year involves more than 20,000 U.S. and 7,500 Australian forces working on about 125 aircraft and 30 vessels, officials said. Field training will take place offshore of Queensland and the Northern Territory in Australia from June 19 to July 2.

Read the rest at Navy Times