THE AGE OF AQUARIUS

Doug KeslingWest Indies Laboratory

Fairleigh Dickinson UniversityTeague Bay, Christiansted

51. Croix, U.S. VIRGIN ISLANDS 00820 U.S.A.

NOAA and the National Undersea Research Center at Fairleigh DickinsonUniversity has recently launched the world's most advanced scientificresearch saturation diving habitat in Salt River Canyon, St. Croix, U.S.Virgin Islands. The new system is called "Aquarius" and replaces NOAA'Ssmaller, less sophisticated habitat Hydrolab, which accomplished nearly200 scientific saturation missions between 1978 and 1985. Aquarius is amobile saturation diving system and began its initial operation duringSeptember, 1987. The habitat represents a major advancement in facilitiesfor scientific saturation diving by providing enhanced scientific capabilitiesin a comfortable living environment. Aquarius makes it possible forscientists to live and work on the ocean floor for virtually unlimited time,allowing a six hour excursion dive time to 95 ft. after a twelve hour intervalis spent at a storage depth of 48 fsw. Six scientific saturation divingmissions are planned for 1988 with the research focusing on nutrientcycling and the control of primary productivity in reef ecosystems andrecruitment processes in marine organisms.

Scientists have at their disposal the most sophisticated saturation diving system everconstructed and dedicated to scientific research in the sea. This new mobile underseahabitat system is called Aquarius and is operated by the National Undersea Research Centerat Fairleigh Dickinson University. NURCIFDU is one of five national undersea researchcenters sponsored by the National Oceanic and Atmospheric Administration's (NOAA)Office of Undersea Research. At present, the Aquarius system is located at Salt RiverCanyon, in St. Croix, U.S. Virgin Islands and plays an integral role in NOAA's CaribbeanMarine Science, Technology, and Ocean Exploration Objectives.

The Aquarius system was developed to support scientific research activitiesrequiring the use of saturation diving techniques. NURCIFDU is building upon the successof it's Hydrolab program which operated in S1. Croix from 1978 to 1985. The ability tolive and work from an undersea habitat can greatly enhance scientific productivity byproviding extended underwater working times while increasing the safety and comfort ofthe research team.

The Aquarius habitat was deployed in Salt River Canyon, St. Croix. in September1987. The habitat system is composed of four major elements; the habitat, the life supportbuoy (LSB), the launch, recovery, and transport vesseVmobile support base (LRTIMSB),and the baseplate. The habitat represents a major advancement in facilities for scientificsaturation diving by providing enhanced scientific capabilities in a comfortable livingenvironment. The habitat consists of an American Bureau of Shipping (ABS) certified

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pressure vessel with three compartments capable of housing and supporting up to 5scientists and one on-board staff technician. It is rated to an external pressure of 54 psi(120 feet of sea water) allowing a maximum saturation depth of 120 ft. Its presentoperational saturation storage depth is 48 feet of sea water.

The LSB was constructed from a 45-foot fisherman-type hull and is permanentlymoored above the habitat. It houses the primary life support systems and an environmentalconditioning unit Electricity, compressed air, water, air conditioning and dehumidificationis all provided to the habitat via an umbilical.

The LRT/MSB is a 100-foot catamaran-type vessel and was designed to serve 3principle roles. The first is to launch and recovery the habitat and transport the system toother research sites around the Caribbean. The second role is to house and transport amobile support base when the habitat is deployed in remote areas where few or no shorefacilities exist. The third is to serve as a "dry dock" facility when periodic inspection andmaintenance is needed on the habitat.

The final component of the Aquarius system is the baseplate which serves as thefoundation and ballast weight for the positively buoyant habitat. The baseplate is designedwith adjustable legs which provide a means of leveling the habitat on an uneven sea floorup to a 10% slope. The baseplate is deployed first from the LRT and positioned on theseafloor. It is then followed by the deployment of the habitat which is hydraulicallywinched down into position on the baseplate.

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Once deployed, the Aquarius system serves as a unique undersea laboratory. Thenew habitat is divided into three compartments; the main lock, entry lock, and wet porch. Itis much larger in comparison to Hydrolab and can accommodate a larger research team fora period of 10 to 30 days. On-board amenities include a climate control system, hotshowers, toilet, microwave oven, refrigerator, and a bunk for every aquanaut whichinsures that the scientists are comfortable and well rested during saturation. Improvedscientific capabilities include a video monitoring and recording system, an integratedcomputer network, remote environmental data acquisition system and a wet laboratory witha flow-through salt water aquarium for observation and experimentation with marineorganisms. Other capabilities allow for a scientist to deploy a variety of small sophisticatedself-contained research chambers and scientific apparatus for in situ sampling, measuringand monitoring of experiments or experimental parameters. This equipment can be linkeddirectly to the habitat for data collection or may run autonomously depending on design.

Diving equipment available to the aquanauts for excursion dives to and from thehabitat include SCUBA, tethered diving equipment, and hookah. SCUBA is most desirablewhen unlimited mobility is necessary and a variety of study sites are to be investigated. Thetethered diving system consists of AGA and EXO-26 full face diving masks a:nd hasproven useful when returning to the same study site day after day or when diver to diver ordiver to habitat communication is required for data collection. A hookah diving system isalso available as another alternative when it may be necessary to access experiments closeto the habitat

The Salt River Subinarine Canyon habitat site has proved to be a unique and highlydesirable location for undersea research. A variety of study sites are accessible from thehabitat and provide principle investigators with a highly diverse Caribbean coral reefecosystem. Six scientific saturation missions were completed in 1988. This year's researchaddressed primarily marine science questions and focused on nutrient cycling and thecontrol of primary productivity in reef ecosystems. The research projects included thefollowing:

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Kesling: The Age of Aquarius

88-1 Primary Productivity and Nutrient Fluxes of Benthic Microflora ofCoral Reef Sediments.

Dr. Tom Fisher from the University of Maryland analyzed benthic microfloraassociated with calcareous sand sediments of coral reef environments. Measurements weremade of sedimentation, bottom currents, physical disturbance, benthic microflora biomassand diel cycles of primary productivity, respiration, and nutrient fluxes from carbonatesands.

88-2 Oxygen Dynamics and Anaerobic Metabolism in Sediments of SaltRiver Canyon.

Dr. Gary King from the University of Maine examined the dynamics of oxygen andthe extent of anaerobic metabolism in carbonate sands. His primary goal was to determinethe distribution of aerobic versus anoxic sediments and to correlate the distribution ofoxygen with both physical as well as biological parameters and processes. State of the artsensors were deployed to detennine flow conditions at the sediment-water interface.

88-3 The Energetics of Sediment Removal and Zooplankton Feeding inCaribbean Reef-Building Corals.

Dr. Jim Porter from the University of Georgia looked at the effects of sedimentremoval in corals by using a in situ respirometer which measured coral respiration todetermine to what extent corals are stressed by sedimentation. Coral feeding studies werealso completed by comparing gut contents of selected corals with available plankton thatwas collected through an elaborate plankton filtering apparatus close to the reef. And, theneurophysiology of coral polyp contraction and relaxation mechanisms were examined withexperimentation focusing on the neuronal basis of light reception in corals.

88-4 Patterns and Processes Structuring Tropical Algal CommunitiesAlong a Depth Gradient: The Dynamic Roles Of Productivity and Herbivory

Revisited.

Dr. Robert Steneck from the Darling Marine Science Center, University of Mainemeasured fish herbivory and the impact of the increased macroalgal abundance caused bythe near mass-extinction of the black spiny sea urchin Diadema antillarum on coral reefcommunities. By using time lapse photography and an in situ biomass harvest andregrowth technique, he quantified rates of primary productivity and herbivory on coralsubstrata covered with algae.

88-5 Zooplankton Capture by Corals: The Effects of Water MovementUnder Field Conditions.

Dr. Kenneth Sebens from ortheastem University investigated the effect of watermovement on several aspects of the feeding biology of corals. Natural and artificiallyinduced water flow parameters were obtained while simultaneously measuring field rates offeeding of three species Qf corals. An automated plankton pump/sampler, Interocean S4current meter, thermistor meter, and Licor quantum irradiance meter provided concurrentmeasurement of prey availability, water flow, and irradiance under field conditions.Underwater time lapse photography and 8 mm. close-up video documented flowcharacteristics and capture events of individual coral polyp tentacles.

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88-6 Field Measurements of Diffusional Boundary Layers and TurbulentEnhancement in Scleractinian Reef Corals.

Dr. Mark Patterson from the University of California, Davis investigated howseawater flow at the boundary layer modulates exchange processes of particulate food,dissolved nutrients, and respiratory gases in several species of reef cnidarians. Experimentsusing gas microelectrodes, heated model organism analogs, and field morphometry wereperformed to understand the effects of organism size, measure frequency of diffusionalboundary layer limitations, and investigate microelectrode diffusional boundary layermapping as a physiological probe for areal exchange.

NURCIFDU invites research proposals from the scientific community who requirethe use of either the new mobile saturation habitat system, ROV's or submersibles toconduct scientific investigations in the Caribbean region. These proposals should addressNOAA's undersea mission objectives in one of the following areas:

Biological Productivity and Living Resources - larval recruitmentprocesses and reproductive biology of coral reef fishes and invertebrates; identification ofnew fisheries species/stocks; primary and secondary production; Food web studies;benthic/pelagic coupling.

Coastal, Oceanic, and Estuarine Processes - production and transport ofcarbonate sands; biological stabilization and disruption of the seafloor; benthic nutrientregeneration and its contribution to primary productivity; history of sea level changes andsea surface temperatures; role of groundwater and terrestrial runoff in tropical coastalenvironments.

Pathways and Fate of Materials in the Ocean - effects of pollutants,sediment loading hurricanes, dredging, blasting, and eutrophication on coral reefecosystems; processes of recovery.

Ocean Services - oxygen toxicity effects, biofouling and corrosion, assessmentof biomedicinals in Caribbean biota, physiological and psychological effects of hyperbaricconditions.

Prospective investigators must submit a preproposal outlining their proposedproject. Preproposal forms can be obtained from the Director of Research. They will bereviewed for topic relevance and'operational feasibility. A fonnal request for proposals willthen be sent to prospective investigators and once returned, will receive mail reviews andbe ranked by a peer review panel. Top rank proposals will be eligible for funds to offset thecosts of travel, per diem expenses, specialized equipment needed for the project, sampleanalyses and technician and graduate student support required for the completion of theresearch. Investigator's salary support and overhead cost will not be provided.

Further information about the AQUARIUS system and the National UnderseaResearch Center at Fairleigh Dickinson University can be obtained from the Director.Please write or call:

National Undersea Research CenterFairleigh Dickinson University

40 Castle CoakleyS1. Croix, U.S. Virgin Islands 00820

(809) 778-1608

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