Further documentation is available here. Most reefs grow best in warm, shallow, clear, sunny nutrient timing for peak performance pdf agitated water.
Often called “rainforests of the sea”, shallow coral reefs form some of the most diverse ecosystems on Earth. They occupy less than 0. However, coral reefs are fragile ecosystems, partly because they are very sensitive to water temperature. This means that most modern coral reefs are less than 10,000 years old.
Reefs that rose too slowly could become drowned reefs. They are covered by so much water that there was insufficient light. Darwin’s theory sets out a sequence of three stages in atoll formation. As the subsidence continues, the fringing reef becomes a barrier reef, and ultimately an atoll reef. Subsequent drilling proved this correct.
Where the level of the underlying earth allows, the corals grow around the coast to form what he called fringing reefs, and can eventually grow out from the shore to become a barrier reef. A fringing reef can take ten thousand years to form, and an atoll can take up to 30 million years. 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 and atolls do not usually form complete circles, but are broken in places by storms. As sea level rose, the water and the corals encroached on what had been hills of the Australian coastal plain. As the sea level rise continued, water topped most of the continental islands.