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New Navy Sonar Could Be the End of Whales
20-Jul-2001

For the last several years the U.S. Navy has been making plans to deploy Low
Frequency Active Sonar (LFA), a new extended-range submarine-detection system
that will create noise billions of times more intense than before in the
world’s oceans. The National Marine Fisheries Service has proposed issuing a
permit that would allow the Navy to proceed with LFA deployment and, in the
process, to harass, injure, or even kill marine mammals while flooding the
ocean with sound. The Navy wants to use LFA to deploy a global surveillance
system to hunt for a new generation of silent enemy submarines. But marine
scientists and environmentalists are fighting the proposal, saying it could
prove lethal to whales and other marine mammals.

The Navy has used sonar to hunt for submarines for decades. Undeniable
evidence that high-powered sonar systems kill marine animals emerged in March
2000, when beach strandings of four different species of whales and dolphins
in the Bahamas coincided with a Navy battle group’s use of extremely loud
active sonar there. Kenneth Balcomb, of the Center for Whale Research in
Friday Harbor, Washington concluded that some whales died from a vibration in
their cranial air spaces that tore delicate tissues around the brain and
ears. The LFA sonar could cause the same damage, he believes. Despite efforts
to save the whales, seven of them died. A National Marine Fisheries Service
and Navy investigation established a connection between the strandings and
the sonar.

The Navy wants to use four sonar ships in the Pacific and Atlantic oceans. On
each ship, an array of 18 loudspeakers, each the size of a Volkswagen, hang
in the ocean at a depth of about 200 feet. LFA functions like a floodlight,
allowing its operator to peer enormous distances into the ocean in search of
enemy submarines. Each one of the system’s long array of transmitters can
generate 215 decibels of sound, a level millions of times more intense than
is considered safe for human divers. After several hundred miles, the sound
waves produced by the array converge, boosting the noise level to more than
240 decibels, the equivalent of the sound generated by an exploding rocket.
Thanks to all these converging sound waves, LFA can explore hundreds of
thousands of square miles of ocean at one time.

For years the Navy has been testing the LFA system in complete secrecy and in
violation of environmental laws. According to a Navy study, scientists
briefly exposed a 32- year-old Navy diver to LFA sonar at a level of 160
decibels -- a fraction of the intensity at which the LFA system is designed
to operate. After 12 minutes, the diver experienced severe symptoms,
including dizziness and drowsiness. After being hospitalized, he relapsed,
suffering memory dysfunction and seizure. Two years later he was still being
treated with anti-depressant and anti-seizure medications.

Whales use their exquisitely sensitive hearing to follow migratory routes,
locate one another over great distances, find food and care for their young.
Noise that undermines their ability to hear can threaten their ability to
function and survive. According to one scientist, “A deaf whale is a dead
whale.”

“There's a possibility that it could disrupt whale communication,” admits
Navy spokesman Lt. Douglas Spencer. “But these systems are operated for a
short period of time (about 430 hours a year) and they’re mobile. It’s
highly unlikely there would be a permanent long-term effect.”

But what concerns marine scientists even more than short- term effects on
individual animals is the potential long-term impact that the Navy's LFA
system might have on the behavior and viability of entire populations of
marine mammals. Sound has been shown to divert bowhead and gray whales and
other whales from their migration paths, to cause sperm and humpback whales
to cease vocalizing, and to induce a range of other effects, from distressed
behavior to panic. It is such long-term effects on vital activities, say the
experts, that pose the greatest risk of pushing endangered species over the
brink into extinction.

A mass stranding of beaked whales off the west coast of Greece in 1996 has
been associated with an LFA-type system being tested by NATO. And last year’s
whale deaths in the Bahamas add further evidence of the risks of intense
active sonar. “The Navy's conclusions that the low-frequency sonar will work
are premature and based on inadequate data,” says Naomi Rose, a marine mammal
biologist at the Humane Society of the United States in Washington.

The Bahamas incident has led some scientists to speculate that military uses
of sonar technology might explain other mysterious strandings. “The Navy
could very well have been causing these kind of traumas all over the world,”
Rose says. “Now comes a technology that is more likely to affect baleen
whales. It’s as loud or louder. Because it’s a lower frequency, it’s going
to travel farther over a larger area. And it’s never been out there before.”


To learn about stopping Low Frequency Active Sonar, click here.



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