Anti-whaling nations win 'GREAT VICTORY' against Japan proposals

According to a report by the scientific committee of the International Whaling Commission, one of the world's leading bodies of whale biologists, the evidence linking sonar to a series of whale strandings in recent years is "very convincing and appears overwhelming." Despite the broad scientific consensus that military active sonar kills whales, the use of this deadly sonar in the world's oceans is spreading.

An NRDC-led coalition of wildlife advocates succeeded in restricting the U.S. Navy's use of a powerful active sonar system known as SURTASS LFA in 2003. But the fight is hardly over; other nations are developing LFA-type systems of their own, and sonar testing using mid-frequency sonar systems, which have been implicated in numerous strandings of whales worldwide, continues unabated, putting marine mammals and fisheries at risk. And the Bush administration is now appealing the legal victory that compelled the Navy into compromise.

snip

Military active sonar works like a floodlight, emitting sound waves that sweep across tens or even hundreds of miles of ocean, revealing objects in their path. But that kind of power requires the use of extremely loud sound. Each loudspeaker in the LFA system's wide array, for example, can generate 215 decibels' worth -- sound as intense as that produced by a twin-engine fighter jet at takeoff. Some mid-frequency sonar systems can put out over 235 decibels, as loud as a Saturn V rocket at launch. Even 100 miles from the LFA system, sound levels can approach 160 decibels, well beyond the Navy's own safety limits for humans.

Evidence of the harm such a barrage of sound can do began to surface in March 2000, when whales of four different species stranded themselves on beaches in the Bahamas after a U.S. Navy battle group used active sonar in the area. Investigators found that the whales were bleeding internally around their brains and ears. Although the Navy initially denied responsibility, the government's investigation established with virtual certainty that the strandings were caused by its use of active sonar. Since the incident, the area's population of Cuvier's beaked whales has all but disappeared, leading researchers to conclude that they either abandoned their habitat or died at sea.

http://www.nrdc.org/wildlife/marine/sonar.asp