Conservation-oriented parks and reserves are fairly common on land, but comparatively few marine regions receive protection from human activities. This situation has, for the most part, elicited little concern, owing to the widely held belief that the large geographic ranges of most marine species would ensure their survival. But new research on restricted-range marine life¿that is, species limited to small areas¿challenges that idea, identifying 10 regions where further damage to coral reefs could lead to a series of extinctions. According to the authors of a study published today in the journal Science, conservation efforts directed at these so-called hotspots could prevent such extinctions and preserve marine biodiversity.

The researchers, led by Callum Roberts of the University of York, analyzed the geographic distributions of 3,235 different species of reef fish, coral, snail and lobster. More than a quarter of the fish and snail species and more than half of the lobsters have restricted ranges, they report. (Only 7.2 percent of the corals appear to have restricted ranges, but the investigators caution that they may well have underestimated coral biodiversity.) Taking these results into consideration along with those of a previous study, the team identified the ocean's most threatened reefs and pinpointed the 10 biodiversity hotspots. Although these areas comprise only 0.012 percent of the oceans, they harbor 34 percent of restricted-range species. The researchers note that the Philippines and the Gulf of Guinea are the top two hotspots. Some of the areas might be best served by joint protection plans, as eight of the 10 marine hotspots adjoin terrestrial ones. In these cases, the authors prescribe an extension of conservation efforts from land to sea.