Coral Reefs

Coral reefs are huge underwater structures made from the skeletons of colonial marine creatures called coral. The coral species that assemble reefs are known as hermatypic, or "hard," corals because they extract calcium carbonate from seawater to make a hard, strong exoskeleton that ensures their soft, sac-like bodies. Different types of corals that are not associated with reef building are known as "soft" corals. These kinds of corals are adaptable organisms frequently looking like plants and trees and incorporate species, for example, ocean fans and ocean whips, as per the Coral Reef Alliance (CORAL), a non-benefit ecological association.