The Navy and several environmental groups reached an agreement this week allowing the service to use a powerful form of sonar during military exercises under way near Hawaii. The accord ends a brief court battle that the Navy had said could threaten national security.
At issue was whether the so-called midfrequency sonar, which blasts strong sound waves under water in hopes of detecting foreign submarines, causes harm to whales and other marine mammals.
Under the agreement, the Navy will use that technology but will be required to post observers who will look for whales or other animals that might be affected. It will also have to limit the sonar's use to areas more than 25 nautical miles from the Northwestern Hawaiian Islands Marine National Monument.
The legal skirmish was touched off a week ago when the Pentagon, in an effort to ensure the Navy's ability to use the sonar during the war games, gave the service an interim national security exemption from the Marine Mammal Protection Act.