for National Geographic News
As the world's oceans become more acidic, the underwater sounds that whales and other marine mammals depend on for survival may turn into a confusing racket, a new study says.
That's because the ocean's ability to conduct sound is expected to increase dramatically due to global warming.
The shift could make it easier for rare whales to find each other and reproduce, researchers say.
More likely, though, the effect would be comparable to a person in a crowded place straining to talk over all the chatter.
"What that means is that the background level of noise in the ocean—say wave noise or ship noise—will increase," said study co-author Peter Brewer, a geochemist at the Monterey Bay Aquarium Research Institute in California.
(Related: "Noisy Eaters Are Cause of Mysterious Ocean Sounds" [August 18, 2008].)
John Hocevar, oceans campaign director for Greenpeace USA, agreed.
"This is a real disaster for marine life," he said.
Soda Water Acid
Sound transmission in oceans is affected by the concentration of various ions, or charged atoms, said Keith Hester, a member of the research team.
The ions are affected by the water's pH, which becomes more acidic as carbon dioxide from fossil fuel burning is absorbed.
The result is carbonic acid, the same acid found in soda water.
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