Reefs are formed by calcium carbonate produced by tiny coral polyps . While corals are the chief architects of reef structure, they are not the only builders. Together these organisms construct many different types of reefs . A coral colony may consist of thousands of polyps. Polyps are typically carnivorous, feeding on small particles floating in the water.
Corals reproduce both sexually and asexually.
An entire colony many meters in diameter can start out as a single polyp. Corals are susceptible to diseases and bleaching . Also, dramatic natural events such as hurricanes can damage coral reefs. Because of the important ecological and economic roles coral reef communities fulfill, an understanding of the stresses and dangers to the reefs is necessary.