Whales And Navy Sonar

The Navy is rolling out its latest plan to manage wildlife in training waters. After years of legal battles, some environmentalists worry the Navy is backsliding in its latest plan.

STEVE INSKEEP, HOST:

News of a cold war between the Navy and whales. The Navy often uses sonar on training missions off Southern California. You know, the ship makes an underwater noise, which bounces off objects and back to the ship. Environmentalists want that to change. Here's Steve Walsh of member station KPBS.

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STEVE WALSH, BYLINE: The Navy destroyer USS Higgins navigates the congested waters of Southern California. During a recent training mission, the crew deploys a Kingfisher, a type of active sonar that trails behind the ship on a long tether. They use it to hunt for mines, but the sound can seriously injure whales. Below deck, the crew monitors a map on a computer screen. Lieutenant Eileen Allerga says that tells them whether it's safe to turn on the sonar as they leave San Diego Bay.

EILEEN ALLERGA: It came up and said there's no restrictions. And it tells us, you know, but - if a whale comes, you know, this close to you, make sure you power down sonar by this much.

WALSH: The Navy created this detailed protocol over several years in response to lawsuits brought by environmental groups. Most of the time, ships use passive sonar, essentially listening to the ocean. But active sonar, which bounces high-intensity sound off an object, is more accurate. The Navy's own studies have shown the impact active sonar has on marine mammals. Even large blue whales will turn away from ships using it. Brett Hartl is with the Center for Biological Diversity.

BRETT HARTL: Many marine mammals - so beaked whales, blue whales, humpback whales - they rely on sound. If they can't hear, if their hearing is damaged, they are basically as good as dead.

WALSH: Some of the Navy's most intense training happens in these waters. Carrier groups train here. The Marines practice amphibious landings. It makes a lot of noise. The training area extends from California to Hawaii. Certain habitat is off limits during parts of the year, including a blue whale foraging area off the coast of San Diego. But every three years, the Navy has to update its plan. Alex Stone is the Navy's project manager.

ALEX STONE: Instead of in the context of litigation, we've looked at everything new using science, using what is practical for us to implement in terms of mitigation measures.

WALSH: Stone says the new plan still takes into account sensitive habitat and lays out when and where the Navy can use sonar and detonate explosives. But environmentalists say the plan erases some of the progress they've fought for over the years. Again, Brett Hartl.

HARTL: The Navy has made progress in the past. They have restricted some of their activities in the past. Now they're sort of backsliding a little bit. And we're concerned about that because there are reasonable ways of dealing with both military training and protecting marine mammals.

WALSH: Environmentalists want the Navy to limit explosions in sonar in areas where they know marine mammals congregate at certain times of the year. But that would likely mean fewer exercises closer to shore, though the Navy resists moving exercises farther out to sea.

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WALSH: At the end of their first day of exercises, the USS Higgins was still close enough to shore that a group of visiting midshipmen from the U.S. Naval Academy could go back to San Diego on board small landing craft. Stone says going farther from shore isn't practical.

STONE: We want to be as efficient as we can with our training. And having our forces steam, you know, hundreds of miles out before they can even start training just doesn't work well.

WALSH: The Navy trains spotters to scan the horizon for marine mammals. They're supposed to shut down exercises if they see a whale breaching nearby. But Hartl says even trained spotters can't see what's under the water.

HARTL: It's hard. I mean, I've been out on the ocean. I've done whale surveys. They're hard to find. Beaked whales are only 10, 15 feet long - and in a big ocean, it's easy to miss them.

WALSH: The new plan to protect marine life is supposed to take effect December 25, but like the last one, it will likely be challenged in court.

For NPR News, I'm Steve Walsh aboard the USS Higgins.

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