Blue whales, such as this one off California, gain new protections from Navy sonar under legal settlement.`

Blue whales, such as this one off California, gain new protections from Navy sonar under legal settlement.

Tom Benson/Flickr (CC BY-NC-ND 2.0)

U.S. Navy to limit sonar testing to protect whales

The U.S. Navy agreed this week to limit its use of sonar and other activities that unintentionally harm cetaceans and other marine mammals.

A federal court on 14 September approved the settlement of two cases brought by environmental groups that challenged the Navy’s training and testing activities off the coasts of southern California and Hawaii. The settlement comes in the wake of the court’s decision earlier this year that found the Navy’s exercises in these areas were illegally harming numerous populations of whales, dolphins, seals, and sea lions.

The decision is being celebrated by conservationists and cetacean experts who have long sparred with the Navy and the National Marine Fisheries Service (NMFS), the federal agency charged with protecting marine mammals, over the sonar tests. “By agreeing to this settlement, the Navy acknowledges that it doesn’t need to train in every square inch of the ocean and that it can take reasonable steps to reduce the deadly toll of its activities,” said David Henkin, an attorney in the Honolulu office of Earthjustice, one of the environmental organizations that challenged the Navy’s latest round of sonar training and testing, in a statement. 

Under the agreement, the Navy will no longer carry out these tests or training exercises, nor set off explosives, in specified habitats around the Hawaiian Islands and southern California. The forbidden areas are known to be vital to marine mammals for reproducing, feeding, and migrating; some also harbor small, resident populations of animals. For instance, a prime feeding area for blue whales is found in the waters near San Diego, and rare beaked whales ply the waters between Santa Catalina and San Nicolas islands.

“It doesn’t mean the Navy has to cut the amount of training they have to do,” says Zak Smith, an attorney at the Santa Monica, California, office of the Natural Resources Defense Council (NRDC), one of the environmental groups involved in the cases and the settlement. “They just won’t do it in some biologically significant areas.”

Since the mid-1990s, NRDC and other organizations have called on the Navy to find safer ways to carry out its explosive training and activities. Marine biologists also began questioning the Navy’s midfrequency sonar exercises, which they suspected were harming whales and other marine mammals. Their suspicions were confirmed in 2000, after more than a dozen whales from four different species were found beached and dying in the Bahamas—an event that a government-led investigation ultimately tied to U.S. naval sonar training.

The powerful sonar blasts that ships such as destroyers deploy to find submarines produce sound waves that can travel across hundreds of kilometers of ocean, disrupting the communication and feeding of marine mammals. At closer distances, the sonar can cause the animals to become deaf and disoriented, leading them to strand. Many of these beached whales have been found with physical injuries, such as bleeding in the ears, brain, and other tissues, and with large bubbles in their organs—damage that’s similar to the “bends,” an ailment scuba divers can suffer if they surface too quickly. Although scientists do not yet know the exact mechanism that causes some species of whales to panic, rush into shallow waters, then strand and die in response to sonar, they don’t question the connection.

Neither does the Navy. The service’s Marine Species Modeling Team prepares environmental impact statements that calculate the likely damage and injury to marine mammals during the training exercises. “They use the best science,” NRDC’s Smith says. In December 2013, the Navy estimated that its proposed training-and-testing plan would affect marine mammals in southern California and Hawaii some 10 million times over the following 5 years, and would permanently injure or kill more than 2000 of the animals. Still, NMFS approved the plan. In response, NRDC, Earthjustice, and other environmental groups filed suit, arguing that NMFS and the Navy had violated the Marine Mammal Protection Act and the Endangered Species Act.

Last March, a federal judge agreed with the conservation organizations. The Navy chose to negotiate the current settlement, recognizing that it “faced the real possibility that the Court would stop critically important training and testing,” if the case continued, Navy Lieutenant Commander Matt Knight, a spokesman for the U.S. Pacific Fleet, wrote to ScienceInsider in an email message. He also pointed out that the Navy employs other “protective measures [to] afford significant protections to marine mammals.”

The agreement applies only to Navy activities through the end of 2018. At that the point, the Navy must apply to NMFS for a 5-year extension.

NRDC’s Smith does not foresee another court battle. “We were adversarial with the Navy for 15 years, but we worked together to reach this agreement. We hope this approach can now be applied in the future and to other areas, such as the Pacific Northwest,” where marine mammals also face threats from naval activities.

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