Coral island

For the novel, see The Coral Island.

A coral island is the result of an atoll whose lagoon has dried up or been filled in with coral sand and detritus. This state is typically the last in the life cycle of an island, the first being volcanic and the second being an atoll. Most of the world's coral islands are in the Pacific Ocean. The American territories of Jarvis, Baker and Howland Islands are clear examples of coral islands. Also, some of the islands belonging to Kiribati are considered coral islands.

A coral island is an island that forms a ring and partially or totally encloses a shallow body of water,or lagoon. It is formed by a build up of depositing lava on top of lava from a volcano that rises up out of the sea. Living organisms begin living around the shores of the new islands. The volcano becomes inactive and sinks,the coral dies, the island forms. The formation is a hard rock like material formed by the skeleton of marine polyps and sand. Most of the coral islands are located in the Pacific Ocean, some of the islands have been designated as a National Monument. Their surrounding waters contain objects of historic or scientific interest. They consist of Wake, Baker, Howland, and Jarvis Islands.

A coral island is formed by small organisms called polyps (pa-lips). Polyps are the builders of coral. These tiny organisms protect themselves by building small walls of limestone around their bodies. These creatures live in small colonies, and over millions of years, these ‘settlements’ become reefs, and then turn into islands.