Scientists dispute Navy's sonar statistics

NORFOLK, Va., June 16 (UPI) -- The U.S. Navy is working to preserve its use of sonar to protect ships amid concerns the technology harms whales and dolphins, experts say.

The (Norfolk) Virginian-Pilot reported Monday that the Navy has used sonar for more than 70 years, but its continued use is threatened by lawsuits brought by environmentalists.

Jene Nissen, environmental acoustics manager for the Navy's fleet forces command, said it's difficult to assess sonar's effect on mammals because scientists have limited knowledge of dolphin and whale behavior.

Worldwide between 1996 and 2006, commercial fishing fleets unintentionally killed or seriously injured nearly 3 million dolphins and whales, Nissen said in a meeting with scientists and reporters.

By comparison, an estimated 37 were killed by mid-frequency active sonar.

Nina Young, deputy director for policy at the Consortium for Ocean Leadership, said she is not so sure.

"A large amount of federal tax dollars in the U.S. go to reducing by-catch in commercial fisheries," Young said. "Some fishing industries have been severely affected by by-catch reduction, and the Navy glosses over that, as if nothing is being done."

Others say the Navy knows about only 37 whale and dolphin deaths, but can't possibly count those that die and don't wash up on shore.