Coral Reef

Sea Zone | Coral Reef | Coral reefs are underwater structures made of calcium carbonate secreted by corals. Coral reefs are colonies of tiny animals found in marine waters with low nutrients. Most coral reefs are composed of stony corals, which in turn consist of polyps that cluster in groups. . Reefs grow best in warm, shallow, clear, sunny and agitated waters.

 

Coral reefs provide ecosystem services to tourism, fisheries and shoreline protection. The annual global economic value of coral reefs is estimated at $ US375 billion. However, coral reefs are fragile ecosystems, partly because they are very sensitive to water temperature.

Most coral reefs were formed after the last Ice Age, when melting ice caused sea levels to rise and flood the continental shelf. This means that most coral reefs are less than 10,000 years old. As communities settled on the shelves, the reefs grew up, pacing, rising sea levels. Reefs which rose slowly drowned reefs could be covered with enough water to insufficient light. Coral reefs are found in the deep sea near the continental shelf, around oceanic islands and atolls in.

The approximately 20,000 years old Great Barrier Reef offers an example of how coral reefs formed on continental shelves. The corals could then overgrow the hills, forming the present cays and reefs.