Coral reefs

Biology: Corals are made by polyps belonging to a group of animals known as Cnidaria, They secrete calcium carbonate and build hard carbonate exoskeletons that support and protect the coral polyps, Feeding via filtration and photosynthesis. Ecology: High productivity in marine waters that contain low nutrients, Reefs grow best in warm, shallow, clear, sunny and agitated waters, Shoreline protection, Habitat for an extremely high biodiversity