Reef ecosystems have been compared to rain forests in terms of biodiversity and density of living organisms. Total area covered by coral reefs is approximately 240,000 square miles. Reefs influence the flow of water around them and have created and protect many islands surrounding them. Coral reefs support a booming tourist economy on the coasts they border. Reefs can provide a number of medicinal compounds.
Reefs serve as atmospheric carbon dioxide sinks.
Coral reefs act as historical climate recorders. Bleaching A. Introduction 1. Lack of coloration is apparent because zooxanthallae populations decline. It is hypothesized that bleaching is an adaptive process in which corals can repopulate with different, possibly more resilient, types of zooxanthallae. Relatively few instances have been linked to sedimentation alone.