Environmentalists have long claimed that sonar harms marine mammals, which use acoustics to mate and forage. Reported mass strandings of certain whale species have increased worldwide since the military started using sonar half a century ago. The sounds scare animals into shallow waters where they can become disoriented and wash ashore. Aside from strandings, biologists are concerned marine mammals could suffer prolonged stress from changes in diving, feeding and communication.
The Navy was recently accused of rushing to obtain five-year permits under the Marine Mammal Protection Act from the National Marine Fisheries Service to increase its sonar testing in U.S. waters without considering the latest science. Marine fisheries officials last month granted the Navy its permit for activities in the Atlantic and Gulf of Mexico, on the condition that the military review the latest science yearly. The Navy must cease exercises if mammals are spotted nearby, and establish a response plan to a mass stranding. A decision on the Pacific permit is expected to be announced this month.