The Navy agreed to limit its use of sonar and other training that inadvertently harms whales, dolphins, and other marine mammals off Hawaii and California in a settlement with environmental groups approved yesterday. The agreement signed by a federal judge in Honolulu includes limits or bans on mid-frequency active sonar and explosives in specified areas around the Hawaiian Islands and Southern California, Earthjustice attorney David Henkin says. Sonar at a great distance can disrupt feeding and communication of marine mammals, and it can cause deafness or death at a closer distance, Henkin notes. In some cases, training exercises can kill: Four dolphins died in 2011 in San Diego when they got too close to an explosives training exercise, he says.
Under the agreement, the Navy cannot use sonar in a Southern California habitat for beaked whales between Santa Catalina Island and San Nicolas Island. Sonar also is not allowed in blue whale feeding areas near San Diego, according to the environmental groups. In Hawaii, the deal prohibits sonar and explosives training on the eastern side of the Big Island and north of Molokai and Maui. The groups said that will protect Hawaiian monk seals and small populations of toothed whales, including the endangered false killer whale. "By establishing some safe havens," Henkin says, deaths and injuries to marine mammals can hopefully be reduced. (Researchers have linked naval sonar to mass strandings of whales.)