Location

Coral reefs flourish in shallow areas (less than 120ft, or 37m) in tropical latitudes, or where warm ocean currents flow into more temperate areas. In deeper waters, not enough light penetrates the depths, which means the reef's main food producers, algae and plankton, cannot photosynthesize. Large reef-building areas include the Caribbean Sea, the western Indian Ocean and the western reaches of the South Pacific. Non-tropical coral reef zones include the Red Sea, where lots of heat from the sun caused by the surrounding desert climate provides the needed warmth, and Australia's Great Barrier Reef, which is kept warm by a tropical Pacific Ocean current.

Reef Life

In addition to the variety of coral polyps whose calcium carbonate actually form the backbone of the coral reef, large numbers of fish, crabs, shrimp, sponges and seagrasses make their home in coral reefs.

Different zones of a reef are better suited to different living things. For example, some types of algae thrive in the rough seaward edge of the reef, where waves are constantly slamming into the coral, and delicate sea-grasses prefer the calm protected water of the sandy reef flat behind the main reef.

Information provided by: http://www.onr.navy.mil