Bubblegum corals and hydrocorals are important components of Aleutian Island coral gardens. (Photo by Alberto Lindner)

Deep-sea corals are widespread throughout Alaska, including the continental shelf and upper slope of the Gulf of Alaska, Aleutian Islands, the eastern Bering Sea, and extending as far north as the Beaufort Sea. Coral distribution, abundance, and species assemblages differ among geographic regions. Gorgonians and black corals are most common in the Gulf of Alaska while gorgonians and hydrocorals are the most common corals in the Aleutian Islands. True soft corals are common on Bering Sea shelf habitats. Overall, the Aleutian Islands have the highest diversity of deep-sea corals in Alaska, and possibly in the North Pacific Ocean, including representatives of six major taxonomic groups and at least 50 species or subspecies of deep-sea corals that may be endemic to that region. In the Aleutian Islands, corals form high density “coral gardens” that are similar in structural complexity to shallow tropical reefs and are characterized by a rigid framework, high topographic relief and high taxonomic diversity.

Deep-sea corals are an important component of benthic ecosystems in Alaska. Highly varied submarine geology, persistent water currents, and plankton rich waters support at least 141 species from six major taxonomic groups. Deep corals have a broad depth distribution within the region. Although, the Aleutian Islands support the highest diversity and abundance of corals in Alaska waters, other subregions, such as the Gulf of Alaska and Bering Sea, support important single-species assemblages of gorgonians, pennatulaceans, and true soft corals.

Gorgonian corals provide important refuge habitat for many of Alaska’s fish and shellfish species.

Many of the commercial fish and crab species currently harvested in Alaska spend all or part of their life cycle in deep habitat where corals are potentially found. As the world population continues to grow and the demand for seafood increases in the future, conservation of Alaska’s deep coral resources will be a major challenge for managers striving to maintain sustainable fisheries. In recognition of the value of both shallow and deep coral habitat conservation, NOAA has listed corals as one of nine programs within the Ecosystems goal in its strategic plan—the only taxa explicitly listed in the Strategic Plan, and the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006 mandates continued research, mapping, and protection of deep coral communities.

Related Links:
The ecology of deep-sea coral and sponge habitats of the central Aleutian Islands of Alaska

Contact:
Bob Stone
Auke Bay Laboratories
Alaska Fisheries Science Center, NOAA Fisheries

Auke Bay Marine Station
11305 Glacier Hwy
Juneau AK 99801
Bob.Stone@noaa.gov