They are a source of food and medicine, and they protect the coast from wave erosion. Many of the tropical islands and most white sand beaches so important for the tourism industry are by-products of reefs. The great beauty of coral reefs attracts the world s seven million scuba divers to travel thousands of miles to remote destinations. The normal scientific process failed to provide answers because there are too few scientists who spend too little time on reefs. There are too few study sites, and few long-term studies.
Many studies emphasize basic research and few use similar methods.
The survey was by far the largest ever undertaken and was based on the use of one method at all sites so that comparisons could be made among sites. The results confirmed that reefs in different parts of the world share similar problems. Overfishing was shown to be far worse than expected, particularly at remote locations. Corals are animals, but they also have microscopic, single-celled plants living in their tissues. Like other animals, coral polyps capture and eat food, but the plant cells provide an additional source of nutritious compounds to the coral.