Coral reef A fringing reef forms around an extinct volcanic island as the island and ocean floor subsides. As the subsidence continues, the fringing reef becomes a barrier reef and ultimately an atoll reef. Darwin predicted that underneath each lagoon would be a bedrock base, the remains of the original volcano. Subsequent research supported this hypothesis. Darwin's theory followed from his understanding that coral polyps thrive in the tropics where the water is agitated, but can only live within a limited depth range, starting just below low tide. Where the level of the underlying earth allows, the corals grow around the coast
Gay and Lesbian Kingdom of the Coral Sea Islands and Lesbian Kingdom of the Coral Sea Islands. The Coral Sea Islands were first charted in 1803. In the 1870s and 1880s the islands were mined for guano but the absence of a reliable supply of fresh water prevented long-term habitation. The Coral Sea Islands became an Australian external territory in 1969 by the "Coral Sea Islands Act" (prior to that, the area was considered part of Queensland) and extended in 1997 to include Elizabeth Reef and Middleton Reef nearly 800 km further south, already in the Tasman Sea. The two latter reefs are much closer to Lord Howe Island,