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
Coral Sea Marine Park Coral Sea Marine Park The Coral Sea Marine Park (previously known as the Coral Sea Commonwealth Marine Reserve) is an Australian marine park located in the Coral Sea off the coast of Queensland. The marine park covers an area of and is assigned IUCN category IV. It is Australia's largest single marine park and is one of the world's largest protected areas. The Coral Sea Marine Park lies directly adjacent to and east of the Great Barrier Reef Marine Park. The Coral Sea Commonwealth Marine Reserve was proclaimed in December 2013, and renamed as a 'Marine Park' in October 2017.