US Navy's mid-frequency sonar could harm divers
30th August 2003
US Navy's mid-frequency sonar could harm divers, whales and dolphins
A San Francisco judge has ordered restrictions on the use of the US Navy's mid-frequency sonar - an intense burst of sound used to locate stealth submarines - on the grounds that it may harm divers, whales and dolphins.
The controversial sonar has previously been tested in the oceans, in 2000 it was linked to the mass beaching of beaked whales in the Bahamas and in May this year is believed to have caused the death of 11 porpoises at the San Juan Islands.
Researchers have observed severe injuries to brain and sensory tissue in mammals subjected to the sonar, and a British study presented in evidence demonstrated that fish can be killed by low-frequency sonar.
A report from a diver subjected to the sonar described a wide range of neurological symptoms including dizziness, loss of hearing and uncontrollable shaking. This resulted in the Navy warning divers in Guam to leave the water prior to their tests in the area.
After considering the evidence, together with submissions from the Navy about their need to use the sonar to identify enemy submarines, District Judge Elizabeth D. Laporte placed a series of restrictions on the use of the sonar. These included prohibiting the use of the sonar in the majority of the world's oceans and requiring the US Navy to work with environmental advocates on a plan for any future use.
The restrictions only apply to peacetime tests and would not prevent the use of the sonar in times of conflict or conditions of heightened US military readiness.