CORALS may be vulnerable to the same processes that cause tooth decay in humans. Healthy coral lives symbiotically with single-celled algae, but fleshy macroalgae spreading over reefs, usually as a result of pollution, can spell trouble.
Now Jennifer Smith of the University of California, Santa Barbara, has shown that sugars released by the algae diffuse into the coral and fertilise bacteria, making them pathogenic. “Algae can indirectly cause coral mortality by enhancing microbial activity,” she says.
Smith and her colleagues took coral and algae from reefs off the Line Islands in the south Pacific and placed them in adjacent chambers…
