Often, soil lodges on the coral and vegetation begins to grow. Many Pacific islands were formed this way. Reefs abound throughout the South Pacific, in the East Indies and the Indian Ocean to Sri Lanka, and around Madagascar on the southeastern African coast. They also form along the tropical eastern coast of Brazil, through the West Indies, along the Florida coast, and at Bermuda. Fringing reefs are submerged platforms of living coral animals that extend from the shore into the sea.
Barrier reefs follow the shoreline, but are separated from it by water.
They form a barrier between the water near the shore and the open sea. A barrier reef may consist of a long series of reefs separated by channels of open water. Such reefs usually surround volcanic islands of the South Pacific. The Great Barrier Reef of Australia, about 1,250 miles long, is the largest coral reef in the world. An atoll is a ring-shaped coral island in the open sea.