Habitat-forming deep-sea corals in the Northeast Pacific Ocean

Abstract

We define habitat-forming deep-sea corals as those families of octocorals, hexacorals, and stylasterids with species that live deeper than 200 m, with a majority of species exhibiting complex branching morphology and a sufficient size to provide substrata or refugia to associated species. We present 2,649 records (name, geoposition, depth, and data quality) from eleven institutions on eight habitat-forming deep-sea coral families, including octocorals in the families Coralliidae, Isididae, Paragorgiidae and Primnoidae, hexacorals in the families Antipathidae, Oculinidae and Caryophylliidae, and stylasterids in the family Stylasteridae. The data are ranked according to record quality. We compare family range and distribution as predicted by historical records to the family extent as informed by recent collections aboard the National Oceanic of Atmospheric Administration (NOAA) Office of Ocean Exploration 2002 Gulf of Alaska Seamount Expedition (GOASEX). We present a map of one of these families, the Primnoidae. We find that these habitat-forming families are widespread throughout the Northeast Pacific, save Caryophylliidae (Lophelia sp.) and Oculinidae (Madrepora sp.), which are limited in occurrence. Most coral records fall on the continental shelves, in Alaska, or Hawaii, likely reflecting research effort. The vertical range of these families, based on large samples (N > 200), is impressive. Four families have maximum-recorded depths deeper than 1500 m, and minimum depths shallower than 40 m. Isidid, primnoid, and antipatharian records all exceed 2500 m depth. GOASEX collections are made from each of seven seamounts surveyed, extending the known range of Coralliidae 2500 km northward and the known limits of Isididae 450 km seaward, beyond the continental shelf, to seamounts in the Gulf of Alaska.