Size really does matter when it comes to conserving the diversity of coral reefs, a new study shows.
Coral reefs are the most diverse of all marine ecosystems with estimates of reef species ranging from 600,000 to more than 9 million species worldwide. But the most pronounced diversity exists in the western Pacific and Indian oceans and decreases with distance in all directions. David Bellwood and Terry Hughes from James Cook University tried to understand this pattern by analysing the numbers of coral and fish species associated with 113 reef communities stretching from the Red Sea to the Gulf of California. By far the best predictor of biodiversity at these sites was the size of the surrounding reef. You need large areas.