Navy Agrees to Restrict Sub-Detecting Sonar

The U.S. Navy has agreed to limit the peacetime use of a new high-intensity sonar to areas including the western Pacific and the Sea of Japan as part of a federal court settlement with conservationists who contend that the sonar may inflict deadly harm on whales, dolphins and other marine animals.

In the settlement, released Monday, the Navy has agreed to restrict testing and training missions that involve a new submarine-detecting sonar to waters off North Korea, China, Japan and the Philippines. The Navy previously had won permission to sweep about three-fourths of the world’s oceans with the sonar system.

The settlement is expected to be approved later this week by U.S. Magistrate Elizabeth D. Laporte in San Francisco, who has sought to balance military readiness with environmental protections. In August, she banned the Navy’s use of the low-frequency sonar in most parts of the world’s oceans, and she ordered military and federal regulators to meet with environmental lawyers and their experts to designate places where the Navy could safety test the system.

The ruling comes as scientists have amassed a growing body of evidence that another type of military sonar is responsible for the deaths of whales and dolphins in the Bahamas, the Canary Islands and most recently along the U.S.-Canadian border above Washington State’s Puget Sound.

Some scientists believe that intense bursts of sonic waves can shake and tear delicate tissues of the ears, brain and other organs, causing hemorrhaging, disorientation and death. Others, writing in last week’s issue of the scientific journal Nature, believe that deep-diving whales and dolphins may panic at loud sounds and shoot to the surface too fast, damaging their internal organs with expanding gas bubbles similar to human divers who die of the decompression sickness known as the bends.

All the dolphin and whale deaths tied to sonar have involved systems that emit mid-frequency waves, using a technology that has been around for decades. The federal case, meanwhile, focused on a newer system, which uses low-frequency sound waves and has never been blamed for marine mammal deaths.

The new system, more powerful than any previous sonar, was designed to hunt for super-quiet diesel submarines. The shipboard sonar system tows an array of speakers capable of releasing 215-decibel bursts of low-frequency waves, which some acousticians compare with standing next to a space shuttle at takeoff. The sound waves can travel hundreds of miles, “lighting up” enemy submarines, before dissipating.

Laporte ruled that the National Marine Fisheries Service was wrong to conclude that this type of sonar would have a “negligible impact” on marine species and that it should not have granted the Navy permission to use the sonar in about three-fourths of the world’s oceans. She said federal law required much greater precautions for peacetime use of the system, and she ordered the Navy and environmental advocates to work out the details.

A National Marine Fisheries Service spokesman declined comment, deferring to the Navy.

Lt. Cmdr. Cappy Surette, a Navy spokesman, said, “It’s not appropriate to discuss the particulars of any agreement until it is made final by the federal court.” He reiterated the Navy’s position that low-frequency sonar is a vital component of its antisubmarine warfare capability, which he said is needed to protect sailors from attacks by super-stealthy diesel submarines in the hands of potentially hostile nations.

Under the agreement filed in federal court last week, the Navy will be allowed to use the sonar off North Korea and China -- two of the nations that have developed quiet submarines. The largest area where it can be used is a 1-million-square-mile quadrant of the southwestern Pacific stretching from the Philippines to Japan.

The Navy also has agreed to stay 30 to 60 nautical miles away from any shore or island to avoid rich, coastal waters where marine mammals and other sea life congregate. The Navy also promised to shut down operations if Navy personnel spot whales, dolphins or sea turtles in the vicinity. None of these restrictions would apply during designated times of a heightened threat or war.

Naomi Rose, a marine biologist with the Humane Society of the United States, applauded the settlement. She urged Congress to reject a Defense Department push to change the Marine Mammal Protection Act and other environmental laws so the Navy could operate more easily without running afoul of the law. “The [proposed] exemptions and changes in the law are unnecessary,” Rose said. “These negotiations show how the law can work for national security as well as for environmental protection.”

The coalition of U.S. environmental groups that sued over low-frequency sonar on Monday was joined by dozens of other conservation and animal-welfare groups in launching an international campaign to regulate intense man-made ocean noise.

Beginning with an appeal to the European public, the coalition plans to bring pressure on members of the North Atlantic Treaty Organization to restrict the use of high-intensity sonar. It will seek to inspire more international research into the effect of noise on marine life and push for intense noise to be regulated as pollution under the U.N. Convention on the Law of the Sea.

Joel Reynolds, a senior attorney with the Natural Resources Defense Council who managed the lawsuit against the Navy, said the goal of the campaign is to “mobilize citizens and scientists from around the world against this destructive technology before it spirals into an arms race.”