Decision Nears On Navy Sonar
BAR HARBOR, Maine (AP) - Eighteen months ago, the Navy deployed a powerful mid-range sonar during a submarine detection exercise in the deep water canyons of the Bahamas.
Within hours, at least 16 whales and two dolphins beached themselves on the islands of Abaco, Grand Bahama and North Eleuthera. Scientists found hemorrhaging around the brain and ear bones - injuries consistent with exposure to extremely loud sounds. Eight whales died.
Now, the March 2000 strandings are being used as a battle cry for opponents of an even stronger low-frequency sonar the Navy wants to use to detect a new generation of quiet submarines.
A growing number of environmentalists and lawmakers want to stop deployment of the system because they fear it will harm whales, dolphins and loggerhead turtles. The state of Maine is particularly concerned about the impact on endangered northern right whales.
``I appreciate the nation's needs for national security, but I also believe that the evidence shows (this new) sonar is harmful to the marine environment,'' said Rep. John Baldacci, D-Maine.
The Navy, which has spent $300 million developing the system, is awaiting a review of its plan for a five-year deployment. A final decision by the National Marine Fisheries Service is expected this fall.
The Navy contends the sonar is imperative to national security because other nations, including Russia, Germany and China, are already developing super-quiet submarines that can avoid traditional detection.
It says it will protect whales with a 1,100-yard buffer zone backed up with traditional sonar and lookouts to determine the presence of whales.
Still, critics say the risk to whales and other marine life under those guidelines far outweighs any advances in submarine detection.
``Sonar is a very important defense, but it's like practicing dropping nuclear bombs - it will have a very important environmental impact,'' said Ken Balcomb, a marine biologist who witnessed the Bahama stranding in front of his house.
Whales are more susceptible to sonar interference than many mammals because they rely on sound for communication, feeding, mating and migration.
The proposed sonar is a type of low-frequency active sonar called the Surveillance Towed Array Sensor System, or Surtass LFA. The Navy wants to use it on four warships capable of sweeping 80 percent of the world's oceans.
According to the Navy's proposal, the sonar would transmit signals as loud as 215 decibels - the underwater equivalent of standing next to a twin-engine F-15 fighter jet at takeoff.
But the Navy contends the loudest noise a whale would encounter is 180 decibels because of the safety zone, said Joe Johnson, the Navy official in charge of managing the environmental tests.
The Navy's tests on four species were able to attain only an estimated level of 150 decibels. At that level, the sonar affected the length of humpback whale songs but didn't lead to other extreme behaviors, said Roger Gentry, an acoustics expert from the National Marine Fisheries Service.
But some biologists believe whales are irritated by sounds louder than 110 decibels. At 180 decibels, they contend, a whale's ear drums could explode - similar to how an opera singer shatters glass.
The Navy admits the Bahamas stranding was likely caused by mid-range sonar but contends the low-frequency active sonar wouldn't harm whales.
Mid-range sonar, used in the Bahamas can be heard over shorter distances by many marine animals. Low-frequency sonar can travel several hundred miles but is audible to fewer animals; the downside is the transmissions are on the same frequency used for communication by many large whales, including humpbacks.
Critics believe there have been other strandings linked to sonar, but the whales in the Bahamas were the only ones to be fully examined.
In 1996, 12 Cuvier beaked whales beached themselves in Greece during NATO (news - web sites) exercises involving the same low-frequency sonar the Navy wants to use. But those whales decomposed before scientists could conduct an investigation.
Marsha Green, an animal behaviorist with the Ocean Mammal Institute in Reading, Pa., fears the worst if the sonar is deployed.
``Can you imagine a world without whales?'' she said. ``It would be like a world without songbirds. We would all regret it.''