Distribution of deep-sea corals and associated communities in the Aleutian Islands  (Year 1 of 2) Project Number: UAF(AK)-03-04 Principle Investigators: Stone, R., J. Heifetz, D. A. Woodby, and J. R. Reynolds Region(s): Adak Island The Magnuson-Stevens Fishery Conservation and Management Act, as amended by the Sustainable Fisheries Act of 1996, requires the regional Fishery Management Councils and the National Marine Fisheries Service (NMFS) to minimize, to the extent practicable, adverse effects from fishing on essential fish habitat including coral habitat. Major fisheries presently occur throughout the Aleutian Island Archipelago and down the continental slope to at least a depth of 1500 m. Summaries of archived data and recently acquired fisheries bycatch specimens indicate that the Aleutian Islands may harbor the highest abundance and diversity of temperate water corals in the world. These data reveal little about the distribution of corals in relation to the overall underwater landscape and the importance of corals to marine ecosystems. In July 2002 Auke Bay Laboratory scientists used the DSV Delta to study Aleutian Island coral habitat in shallow water (0 - 350 m depth) near the Andreanof Islands and on Petrel Bank in the Bering Sea. Coral and sponges were found at 30 of 31 dive sites investigated and percent coverage ranged from approximately 5% on pebble substrate to 100% coverage on bedrock outcrops. Unique coral habitat consisting of high density “gardens” of corals, sponges, and other sessile invertebrates was found at 5 sites between 150 and 350 m depth. These “gardens” were similar in structural complexity to tropical coral reefs. This habitat had not been previously documented in the North Pacific Ocean or Bering Sea. Disturbance to epifauna, likely anthropogenically induced, was observed at most dive sites and may have been more evident in heavily fished areas. Scientists propose to use a remotely operated vehicle (ROV) in 2003 and 2004 to determine the lower depth distribution of corals and in particular to determine if “coral garden” habitat is found at depths below 350 m. Multibeam bathymetry +/- backscatter basemaps will be created prior to the ROV dives. In situ observations and videographic data will be collected on strip transects between 350 and 2750 m depths. Transects will be linear extensions of shallower transects established in 2002 and those planned for 2003. Ultimately, the goal is to construct a model that predicts the distribution and density of coral habitat throughout the Aleutian Islands based on depth, substrate type, habitat type, oceanographic parameters, and geological features. Fishing effort and predicted coral habitat distribution data will be entered into a geographical information system to create maps showing areas of coral habitat and fishery interaction. The scientific goals of this work are to study the zoogeography, ecology, and life history aspects of deep-water corals. This information will also directly assist managers in developing methods to minimize fishing interactions with coral habitat in the Aleutian Islands.   SUMMARY OF CRUISE RESULTS: Dives were made with the ROV Jason II at ten sites in the Central Aleutian Islands ranging at depths from 2948 m to 131 m. Video footage of the seafloor was collected along strip transects ranging from 13.2 to 2.4 km in length. Corals and sponges were widely distributed at the study sites with an apparent change in density, diversity, and species composition at a depth of approximately 1400 m. Samples were collected at stations along transects and included 260 corals, 45 sponges, 165 miscellaneous invertebrates, and 82 rocks. Preliminary results indicate that representatives from all seven coral families known to occur in the North Pacific were collected and that several of the collected sponges represent species new to science. GENERAL SCIENTIFIC CONTRIBUTION OF THE CRUISE:Results from this cruise will provide information regarding the distribution of corals and sponges in the Aleutian Islands that will be critical to fisheries management there. Our findings will greatly add to our understanding of the role of corals and sponges in seafloor ecology and their susceptibility to disturbance. We anticipate that many of the specimens collected will be new to science. SPECIFIC ADVANTAGES OF RESEARCH TO NURP: The research addressed the West Coast and Polar Regions Center’s programmatic theme “Exploratory Research: Western Gulf of Alaska – Aleutians 2004” and secondarily the themes “Fisheries Research” and “Shelf and Slope Ecology”. The research also follows the NURP Science Guidance Plan by conducting research to map important fish habitat, to develop a better understanding of the role of deep-sea corals in benthic ecosystems, and to identify habitat components potentially threatened by disturbance from fishing gear. This was the first directed deep-sea exploration in this area of the Aleutian Islands and we anticipate many important publications. NURP will be credited with these accomplishments. *Only one report is required per research cruise. Project No.: PI: Robert Stone OPERATIONAL DETAILS: Weather and water conditions affecting operations: Weather conditions overall were excellent for ROV operations, and the roll compensator on the RV Roger Revelle markedly increased the ship’s stability. No dive operations were lost due to wind or sea state conditions. Strong surface currents affected several dives, especially those in Amchitka Pass. There is some question whether these currents would have hampered diving activities if the RV Revelle’s dynamic positioning system had worked properly. Dive J2-097 was terminated early due to major failure of the ship’s traction winch. The ship’s engineers repaired the winch in 6 hours and there was no damage to the ROV cable. Dive J2-106 was terminated early when the ROV Jason II/Medea and its fiber optic cable snagged on a derelict longline west of Kanaga Island. Derelict fishing gear was sighted at other dive sites as well. Safety problems and concerns: The traction winch had a significant failure during one dive and there was significant damage to the winch and winch room. The incident was contained to the unoccupied winch room and posed no safety problem to crew or scientific personnel. Otherwise there were no safety concerns. Dive management and personnel cooperation: The Jason II expedition team from Woods Hole Oceanographic Institution managed dive operations and cooperation between the expedition team and the scientific team was excellent. The Jason II team in particular made an extraordinary effort to accommodate our science needs by adjusting the ROV operations for a daily rhythm of launch and recovery with only a few hours time on deck. Dive time was maximized since the ROV was idle on deck only during transit from one site to the next on most days. Logistics and support activities: The captain and crew provided very good support throughout the cruise and were flexible regarding schedule changes necessitated due to weather and personnel scheduling. The cruise terminated in Honolulu, Hawaii and this proved to be a very difficult port from which to transport scientific specimens (hazardous materials).

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