(Related story: Whales at Risk From New U.S. Navy Sonar Range, Activists Say [November 3, 2005])
The appellate court said the Navy has acknowledged that high-powered sonar may cause hearing loss and other injuries to marine mammals.
The court said the Navy has estimated that its Southern California exercises would expose more than 500 beaked whales to harassment and would result in temporary hearing loss to thousands of marine mammals.
The ban requires the Navy to limit the decibel levels of its sonar under certain ocean conditions and to stop using it altogether when a marine mammals is detected within 2,200 yards (2,000 meters) of a sonar source.
The Navy said those restrictions would limit its ability to conduct anti-submarine warfare training and possibly prevent certification of some naval strike groups preparing to deploy to the Persian Gulf.
The appellate court staggered the sound-level reductions during certain ocean conditions and tied them to the proximity of a marine mammal. The court also said the Navy can continue to use sonar—although at a lower sound level—when a marine mammal is within 2,200 yards (2,000 meters) if the sonar is being used "at a critical point in the exercise."
Hawai'i
In the Hawai'i decision, U.S. District Judge David Ezra ordered the Navy to look for marine mammals for one hour each day before using sonar, employ three lookouts exclusively to spot the animals during sonar use and stop sonar transmission altogether when one of the mammals is within 500 meters, which is nearly 547 yards.
The Navy plans to conduct as many as 12 exercises off Hawai'i over the next couple of years. Navy officials say Hawaiian waters provide a unique environment that includes both deep and shallow areas to train in.
The Navy undertakes "extensive measures" to protect marine mammals during training and is considering asking for more review, possibly by the U.S. Supreme Court, said spokesperson Lt. Cmdr. Cindy Moore.
"We're a country engaged in two wars. When we send America's sons and daughters into harm's way, we must ensure they have the best possible training," she said.
———
Associated Press writer Sudhin Thanawala in Honolulu contributed to this report.
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
