EARTH SCIENCE > OCEANS > COASTAL PROCESSES > CORAL REEFS
Underwater structures made from calcium carbonate secreted by corals. Corals are colonies of tiny living animals found in marine waters containing few nutrients. Most coral reefs are built from stony corals, and are formed by polyps that live together in groups. The polyps secrete a hard carbonate exoskeleton which provides support and protection for the body of each polyp.
Derived from: Garrison, T. 1993. Oceanography, An Invitation to Marine Science. Wadworth Publishing Co. p. 518.