Corals are found worldwide and in every ocean basin. This cold water coral, Stylaster alaskanus, is one of over 20 species among 7 genera of hydrocorals reported in Alaskan waters.
Cold water corals are azooxanthellate, meaning they do not rely on symbiotic algae so are not restricted by light availability for survival. About half of all known coral species are azooxanthellate, and only a handful of these corals build reefs. For example, Lophelia pertusa builds cold, deep reef habitats that support diverse communities of fish and invertebrates.