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SCIENCE IN THE NEWS

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The reburial and research project cost twenty-five-million dollars and took thirteen years to complete. The federal government paid for it. Plans for building on the burial place have been canceled. The ground is now considered an important historic area.

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VOICE TWO:

The United States Navy has agreed to limit its use of a new sonar system that critics say could harm whales and other sea animals. The Natural Resources Defense Council, an environmental group, led the effort to restrict the use.

The sonar system is designed to search for submarines that are especially quiet. It sends loud, low frequency sound waves through the water. When the sound waves hit an object, its presence is confirmed. The sound waves can travel farther than sonar in common use today. The noise can be as loud as a rocket launch.

VOICE ONE:

This sonar system and others that produce sound waves are called active sonar. Researchers say there is evidence that all active sonar may threaten sea animals.

Nature magazine recently published findings by British and Spanish researchers. They examined fourteen whales that died on the beach in the Canary Islands last year. The whales got trapped on land a few hours after the start of international naval exercises led by Spain. One American ship took part. The exercises involved the use of mid-frequency sonar.

The scientists found that ten of the whales had bubbles in their blood system. They also discovered evidence that major organs had bled. The researchers say the most likely cause was a form of decompression sickness, also called the bends. This can happen to divers when they rise from deep water too quickly. The pressure change releases bubbles of nitrogen gas into the blood system. These bubbles can block passages.

VOICE TWO:

Traditional thinking is that whales and other ocean mammals are protected against the bends.

The study leader, Paul Jepsen, says more research is needed to learn how the whales got sick. But he says he is sure the mid-frequency sonar was connected. He says the noise may have frightened the whales and led them to surface too quickly. Or, he says, the mid-frequency sonar may have caused the nitrogen bubbles to form in their blood system. Mister Jepsen is a scientist with the London Zoological Society.

VOICE ONE:

United States Navy officials say there has been no evidence that their new low-frequency sonar harms ocean animals. They say it will improve national security. But Navy officials agreed this month to limit the use to an area off the coast of east Asia. The area includes China, Japan, North and South Korea and the Philippines. But it represents only one percent of the area in which the Navy had first received approval to use the sonar.

Under the agreement, the Navy cannot use the sonar within fifty to one-hundred kilometers of coastlines. It also bars use during seasonal times when whales travel through the area.

Researchers say the sonar could interfere with whale communication. Many whales produce sounds at the same low frequencies.

VOICE TWO:

In August, a federal judge in California had restricted the use of the system, and ordered the negotiation of a final settlement.

All restrictions would be suspended in time of war or increased threat.

The National Resources Defense Council says it is extremely pleased with the agreement. And it says it will start an international effort to seek similar rules about the use of active sonar around the world.

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VOICE ONE:

Science in the News was written by Nancy Steinbach, Caty Weaver and Cynthia Kirk, who was also our producer. This is Sarah Long.

VOICE:

And this is Bob Doughty. Join us again next week for more news about science, in Special English, on the Voice of America.

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