The oceans are becoming so noisy, that whales can hardly hear each other sing. The Navy admits that loud booms from its underwater sonar listening devices result in temporary or permanent hearing loss for more than a quarter-million sea creatures every year–not to mention the noise from outboard motors on boats.
But whales are protecting themselves: They are somehow able to close their ears when loud noises go off. In the July 17the edition of the New York Times, William J. Broad quotes marine biologist Paul E. Nachtigall as saying, "It’s equivalent to plugging your ears (with your fingers) when a jet flies over. It’s like a volume control." This means that the military may be able to develop warning signals that would alert whales, dolphins and other sea mammals to upcoming auditory danger.
Broad quotes oceanographer Carl Safina as saying, "I’ve sometimes wondered why these high intensity sounds don’t cause problems all the time. Maybe it’s that, once the animals hear something very loud, they can adjust their hearing–dial it down and protect themselves."
The world’s oceans have been getting increasingly noisier, as companies and governments expand their undersea activities, such as oil drilling (NOTE: Subscribers can still listen to both of these wonderful shows).
The noise threat arises because of the basic properties of seawater. While light can travel for hundreds of feet through ocean water before disappearing, sound can travel for hundreds of MILES.
And the problem is getting worse: The Navy says it has plans for underwater activities that could raise the annual hearing losses among sea mammals to more than one million, something which Broad quotes advocacy lawyer Zak Smith as saying is "staggering."