Crab spied in black coral

The manipulator arm of the remotely operated Jason II vehicle closes in on a black coral and deepwater king crab, found at a depth of 2160 meters just south of Amlia Island in the Aleutian Island chain during the first dive of the cruise, Monday, July 26. It may be the first documentation of a king crab using a black coral colony as a platform, perhaps to feed, said fishery biologist Bob Stone. During this dive, the scientists observed that king crabs were often found in the presence of corals, indicating that the crabs are using the corals as habitat.

Location: South of Amlia Island, 2900 meters depth

Posted 07.27.04 at 3:42 pm

Among the notable first observations of this cruise, researchers using Jason II to explore the ocean floor near Amlia Island observed a crab perched on a black coral.

The coral was collected and preserved by researchers for study; the crab got away.

The unmanned dive went to a maximum depth of 2900 meters, lasted more than 20 hours and was orchestrated by technicians and NOAA researchers on board the research vessel Revelle. Video from the expedition dives is being used to better understand Aleutian coral habitat.

Black coral is commercially harvested in shallow water by SCUBA divers in Hawaii, the Caribbean and New Zealand for jewelry-making. Alaskan black coral is found in deep waters (below 600 meters),and is smaller and has a thin flexible skeleton which is brittle when dried - which makes it not suitable for the jewlery trade; therefore it is not harvested.

See a close up of the crab, and a long view of the crab and the coral.