The U.S. Navy will restrict the use of low-frequency active sonar during training to prevent possible harm to whales and other creatures, under an agreement reached with environmental groups Tuesday.
The accord, approved by a federal court in San Francisco, would restrict the use of a type of sonar in areas in the Pacific Ocean that are known to be whale breeding grounds and key habitat, such as the Humpback Whale National Marine Sanctuary off Hawaii.
The Navy and environmentalists have been jousting in court for several years over the risk to whales and other marine life posed by underwater noise from sonar exercises. A separate lawsuit, not involved in Tuesday's announcement, involves mid-frequency sonar. That case is pending at the U.S. Supreme Court.
Navy officials insist that the sonar exercises are essential for sailors to train to detect ultra-quiet submarines being developed by nations such as Iran and North Korea. Environmentalists say the Navy is needlessly harming whales and other marine mammals and that training can be conducted in spots where whales are not common.
"Limiting sonar use in breeding grounds and other key habitat areas is essential for the conservation of whales, dolphins and other marine mammals," said Naomi Rose, marine mammal scientist for the Humane Society of the United States. "This agreement protects both national security and our most treasured natural resources."
A Navy spokesman at the Pentagon said the agreement was reached Friday and signed by the judge Tuesday. "We get some areas to train and they get some areas that are off-limits," the spokesman said.
Tuesday's agreement involved a lawsuit filed last year challenging the National Marine Fisheries Service's approval of the Navy's low-frequency sonar exercises. Environmentalists asserted that the fisheries service had violated the Marine Mammal Protection Act and the National Environmental Policy Act.
In February, U.S. Magistrate Elizabeth D. Laporte ordered the Navy to hammer out a compromise with the environmentalists over the low-frequency sonar issue.
After reviewing classified documents, Laporte agreed that the Navy needed to train with sonar but ruled that it could avoid areas where whales and other marine life could be harmed.
The waters surrounding Hawaii have become a flash point in the whale dispute. The Navy says the underwater topography is similar to that found in the Strait of Hormuz at the entry point to the Persian Gulf, a transit point for tankers carrying a large percentage of the world's supply of oil.