Coral reef to form fringing reefs, and can eventually grow become a barrier reef. Where the bottom is rising, fringing reefs can grow around the coast, but coral raised above sea level dies. If the land subsides slowly, the fringing reefs keep pace by growing upwards on a base of older, dead coral, forming a barrier reef enclosing a lagoon between the reef and the land. A barrier reef can encircle an island, and once the island sinks below sea level a roughly circular atoll of growing coral continues to keep up with the sea level, forming a central lagoon. Barrier reefs
Middleton Reef Middleton Reef Middleton Reef is a coral reef in the Tasman Sea. It is separated by a deep oceanic pass some 45 km wide from nearby Chan Reef, forming part of the Lord Howe Rise underwater plateau. It is around 220 km from Lord Howe Island and 555 km from the coast of New South Wales. In 1997 the Environment, Sport and Territories Legislation Amendment Bill 1996 included the reef in Australia's Coral Sea Islands Territory. It is among the southernmost platform reefs in the world. Despite its relatively high latitude, there is a wide variety of flora and fauna