Why a federal court ruled against the US Navy, in favor of whales

A California appellate court ruled against the US Navy's use of low-frequency sonar, a long-debated practice that is harmful to marine mammals.

A new court ruling has been issued in the ongoing conflict between the US Navy and marine wildlife advocates. This time, the ruling has come down in favor of whales, dolphins, and other marine mammals that are adversely affected by naval use of sonar.

Sonar, which involves navigation or detection of underwater objects using sound waves, is a natural phenomenon used by whales and dolphins to locate prey or members of their pod. Yet the human-developed version of sonar can be harmful to marine mammals and their feeding and mating patterns.

Friday's decision by the Ninth U.S. Circuit Court of Appeals in California found that a 2012 decision to allow the naval use of low-frequency sonar for training, testing, and operations was out of step with language in the Marine Mammal Protection Act. That act says that peacetime oceanic programs must have "the least practicable adverse impact on marine mammals."

Rules set in 2012 by the National Marine Fisheries Service permitted the US Navy’s sonar use to affect about 30 whale species and two dozen pinnipeds, such as seals and sea lions, and required the Navy to shut down sonar if the animals were near. The approval of the use of this technology covered peacetime operations in the Pacific, Atlantic, and Indian Oceans and the Mediterranean Sea, the Associated Press reports.

The appellate panel explained that they felt that the fisheries service "did not give adequate protection to areas of the world's oceans flagged by its own experts as biologically important," according to a summary released with the court's decision Friday.

This decision is in contrast to a 2008 Supreme Court ruling which reversed a California judge’s restrictions on naval use of sonar.

“We do not discount the importance of plaintiffs’ ecological, scientific, and recreational interests in marine mammals,” Chief Justice John Roberts wrote for the majority at that time. “Those interests, however, are plainly outweighed by the Navy’s need to conduct realistic training exercises to ensure that it is able to neutralize the threat posed by enemy submarines.”

Last year, environmental groups, led by the Natural Resources Defense Council, who oppose the sonar, received another victory when a federal judge in Honolulu signed an agreement banning or limiting mid-frequency active sonar and explosives in certain parts of Southern California and the Hawaiian islands.

That ruling included explosives training that the Navy at that time said had caused the death of 155 whales and dolphins in the area. Estimates for serious injuries were much higher, in the range of 2,000 in Hawaii and South California waters, The Christian Science Monitor reported last year.

The use of sonar, which was the subject of Friday’s ruling, has been shown to cause whales to swim hundreds of miles, change depth with a pace that causes injury to the whales, or beach themselves in order to avoid what Scientific American calls “rolling walls of noise” that are nearly double the decibel level of the loudest rock concert.

The Natural Resources Defense Council has been involved in lawsuits against the use of this technology as part of a larger campaign to limit man-made oceanic noises that impact the health, feeding, and breeding patterns for marine mammals. Other examples include sounds caused by shipping vessels and seismic oil and gas drilling. 

This latest ruling, as well as last year's Honolulu decision, may suggest a greater emphasis on minimizing human impact on the habitat of sea mammals.