Press Releases

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ISSUED: July 10, 2000

Aquarius Mission to Study Predators on Conch Reef
KEY LARGO, FLORIDA --- People do not usually think of corals in the same way that they think of sharks, but both are predators. While sharks chase large prey, corals wait in the watery darkness of night and prey on nearly microscopic zooplankton that drift by, or swim too close. A team of scientists led by Drs. Ken Sebens and Karla Heidelberg (University of Maryland) will spend ten days fifty feet underwater in Aquarius, the nation's only underwater laboratory, to document exactly how corals feed, and what they eat. They will be collaborating with Drs. John Bythell and Jeremy Thompson (University of Newcastle, England).

Aquarius is the world's only undersea laboratory dedicated to science, and is operated by the University of North Carolina at Wilmington (UNCW) for the National Oceanic and Atmospheric Administration (NOAA). The underwater lab is 3.5 miles offshore near Key Largo, in the Florida Keys National Marine Sanctuary. Aquarius provides computers, power, and the necessary bottom time that allows the scientists (called Aquanauts) to conduct their studies directly on the reef - day and night.

Interestingly, corals feed primarily at night because that's when more zooplankton are in the water. But corals are attached to the bottom by their hard skeletons, so how do they hunt? Corals have tentacles that are armed with tiny, poisonous stinging cells, that can be discharged into prey that happen to float or swim into range. The special stinging cells help to immobilize and hold the prey, until transfer into the coral mouth. The research team will document this hidden world of coral feeding biology using high-resolution infrared video cameras and specially designed sampling devices. The aquanauts will spend considerable time on the reef at night, setting up experiments and collecting data.

The Aquanauts will also study how water motion affects coral feeding and growth. Even at short distances, the rate of flow over and around corals can change dramatically. This is significant because water motion has large impacts on coral biology, affecting processes such as growth, competition, larval dispersal, fragmentation, and sedimentation. Water motion also delivers prey to corals and enhances the uptake and exchange of nutrients, oxygen, and carbon dioxide. The aquanaut team will deploy sophisticated equipment to measure current speed and direction at the site, as well as flow over and around individual corals.

After the Aquanauts spend time diving on the reef each day - dives that average between three and four hours are common - they swim back to their underwater home and laboratory - Aquarius. Hot food, warm bunks, Internet access, and sophisticated equipment are all immediately at hand inside Aquarius. Living quarters are tight, and resemble a high-tech motor home in terms of size and comfort. During this mission, Mike Hutchens and Thor Dunmire are the UNCW onboard specialists who run Aquarius from inside. Hutchens and Dunmire are supported by a highly trained shore-based team who work from Mission Control, ten miles away in Key Largo. This month, ocean data (underwater temperature, salinity, and current speed and direction) will be posted live on the internet at UNCW's Aquarius website: http://www.uncwil.edu/aquarius, along with web cameras inside and outside Aquarius, expedition journals from the aquanauts, and detailed project information. A virtual reality tour of Aquarius is also available.

Information collected during this Aquarius mission is related to understanding the distribution and abundance of corals on reefs, especially in Florida where substantial human impacts occur and significant natural system variation in water quality frequently occurs.

For additional information please contact: Dr. Steven Miller, Center Director, National Undersea Research Center, University of North Carolina at Wilmington, Center for Marine Science. 305-451-0233, millers@uncw.edu. Or: Mimi Cunningham, University Relations. 910-962-3171, cunninghamm@uncw.edu.