Military Sonar Blamed for Mass Dolphin Strandings

[babylonsister]

Military Sonar Blamed for Mass Dolphin Strandings

by Lewis Smith

Mass strandings of dolphins and whales could be caused because the animals are rendered temporarily deaf by military sonar, experiments have shown.



Tests on a captive dolphin have demonstrated that hearing can be lost for up to 40 minutes on exposure to sonar. Hearing is the most important sense for dolphins and other cetaeceans, and losing it is likely to cause them to become disorientated and alarmed.

The finding by the Hawaii Institute of Marine Biology may explain several strandings of dolphins and whales in the past decade. Most strandings are still thought to be natural events, but the tests strengthen fears that exercises by naval vessels equipped with sonar are responsible for at least some of them.

The study also suggested, however, that dolphins and whales would usually be able to swim away fast enough and far enough to escape any ill effects from sonar.

To induce deafness in the Atlantic bottlenose dolphin, Tursiops truncatus, the sonar device would have to be loud, close and would need to last for at least two minutes.

This should give the animals plenty of time to escape but in some circumstances noises can be caught in "underwater sound traps", Aran Mooney, of the University of Hawaii, said.

more...

http://www.commondreams.org/headline/2009/04/08-2

[NightWatcher]

1. Duke and UWC are about to start a study for the Navy studying off the coast of Jax, FL

Before they can start (yeah right) actively pinging like crazy, they want to see what's out there and what would be harmed by the Navy using this huge area (up to 90 miles off shore) as a playground. They are going to spend the first year of the study trying to determine what species exist and travel through the area. My SO is trying real hard to get the team leader job for the aerial and ship based survey crew.

That military sonar is some bad stuff to the delicate fish and marine mammals in the region, and the sonar waves travel so far before they stop causing harm.