Coral Reefs Hang On — In Spite of It All

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It's not every day that coral reefs make headlines, so it was a surprise last week when they were in the news three times. Although most of the reports, published in the journal Science, were discouraging, there was at least some hope that the future of these fragile formations might not be as bleak as environmentalists fear.

The worst news came out of a joint U.S.-Australian study in which scientists announced that the world's coral reefs may have only a few decades to live. The two biggest threats are diseases, which hit harder when coral organisms are environmentally stressed, and bleaching — the loss of beneficial algae due to rising global temperatures. The investigators involved in the study believe human impact goes back much further, to our hunter-gatherer days. Analyzing the evolutionary history of 14 reefs around the world, they found evidence of ancient, land-based pollution that has long been toxic to coral. Additionally, centuries of overfishing may have disrupted the food chain, allowing the overgrowth of other types of algae, which compete with coral for food. This accumulated stress has made reefs vulnerable to modern disease. "The patient is terminally ill," says marine biologist John Pandolfi of the National Museum of Natural History — Smithsonian Institution in Washington, "but the underlying sickness is pollution and overfishing."

Studies headed by the Australian National University show that reefs may be vulnerable to another environmental insult: wildfires. A new report suggests that smoke from 1997 Indonesian fires deposited iron on the surface of the water, leading to the growth of phytoplankton. This caused a so-called red tide that suffocated the coral. The only good reef news comes from a new four-nation study suggesting that while climate change certainly isn't good for coral, the tiny organisms may do better than we think at adapting to new conditions. Species with a tolerance for warmer waters may already be emerging. This flicker of hope notwithstanding, scientists agree that the world's reefs need to be protected, mostly with stricter pollution controls and expanded "no-take areas," which keep humans out and let the reefs grow in peace.