How Coral Reefs are Made

  Coral reefs are made of tiny, dead, soft little sea creatures called coral polyps. The polyps remove calcium from the ocean water and with that, they make a hard 'shell' called corallite, or calcium carbonate. When the polyps die, the corallite stays behind, like a skeleton. It takes millions of dead polyps to make just one piece of coral. There are many kinds of coral, such as sea fan, brain coral, and sea whip. All the different kinds of coral are formed by different polyps.