This is the VOA Special English ENVIRONMENT REPORT.
American officials have approved a plan for the United States Navy to use loud, low-frequency sound wave devices on two ships in the world's oceans. The new sonar system will be used to search for especially quiet submarines. The device works by sending sound waves through the water. When the sound waves hit an object, its presence is confirmed.
The new sonar system can find objects ten times farther away than the sonar used now. The Navy plans to use the new system in eighty percent of the world's oceans. The noise from the sonar device is about as loud as a large airplane leaving the ground.
The Navy has permission to use the new sonar system for five years. Officials say the Navy will have to follow rules on when and where to use the sonar devices.
They say the Navy will not be permitted to use the sonar if whales are seen within two kilometers of the ships. The sonar also will be banned within nineteen kilometers of any coast.
The Navy also is required to investigate the possible effects of the sound waves on ocean animals. This includes the ability of whales to communicate with each other. The officials say these measures will protect the animals from any serious harm.
However, environmental activists do not agree. One group, the National Resources Defense Council, may take legal action to try to stop the Navy's plans. The group criticizes putting the system into operation before knowing its possible effects.
The National Resources Defense Council also notes that past military sonar has killed whales. Two years ago, the Navy used very loud sonar devices in deep waters around the Bahama Islands. More than fifteen whales and a dolphin later were found trapped on land along several coasts. At least six of the whales and the dolphin died.
The National Marine Fisheries Service and the Navy investigated the incident. Investigators said the noise from the sonar led to the deaths of the ocean animals. They also found that all but one of the dead whales had bled around the brain and ear bones.
The Navy says the new sonar system is necessary because other nations are developing quiet submarines. It says the effect on sea life will be minor.
This VOA Special English ENVIRONMENT REPORT was written by Caty Weaver.