"Marine mammals like dolphins and whales use sound like humans use sight," says Roger Gentry, oceanographer (ocean scientist) for the National Marine Fisheries Service in Silver Spring, Maryland. "If they can't hear, they could die." Whales, for example, communicate within their own group or pod through sounds as high as 20,000 hertz--the same frequency as most of today's ocean racket.
Also, sound travels four times faster in water than in air: 1,230 meters per second versus 340 meters per second-- because water molecules are packed tighter than air molecules. So underwater sound travels longer distances before it diminishes. A dolphin swimming along the California coast may be able to hear deep-sea drilling 7,000 miles (11,300 kilometers) away off the China coast! Researchers have no concrete data on how ocean noise pollution will impact sea life. But they do know such noise is definitely not music to fish ears!
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|Title Annotation:||the increasing amount of noise in the ocean may be harmful to marine life, especially marine mammals|
|Article Type:||Brief Article|
|Date:||Oct 4, 1999|
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