BEIJING, Dec. 22 — The world’s oceans are becoming noisier because of pollution and the altered deep sea’s acoustic environment is potentially harmful for marine life, U.S. scientists said in a report quoted by media Tuesday.

The report published in the journal Nature said the concentration of chemicals that absorb sound in the oceans has dropped off due to ocean pollution.

According to the report, low-frequency sound is absorbed mainly through the viscosity of the water and the presence of certain dissolved chemicals, but the chemicals’ concentration has reduced as a result of ocean acidification, caused by rising concentrations of carbon dioxide.

By using model simulations, the scientists found that increases in acidity could reduce seawater sound absorption by as much as 60 percent by 2100 in high latitude oceans.

Concern about the negative effect of the sea’s acidification has previously been concentrated on the reduced rate of calcification, such as in coral reefs.

“However, a less anticipated consequence of ocean acidification is its effect on underwater sound absorption,” said the scientist behind the report Tatiana Ilyina of the School of Ocean and Earth Science and Technology at the University of Hawaii in Honolulu.

High levels of low-frequency sound can have biological effects on marine life, including tissue damage, mass stranding of mammals such as whales and temporary loss of hearing in dolphins, according to the report. 

On Xinhua Web site: http://news.xinhuanet.com/english/2009-12/22/content_12686967.htm