Skip to content

Changes in Florida Keys coral reefs studied

Changes in Florida Keys coral reefs studied
KEY LARGO, Fla. (AP) — Marine scientists began a nine-day mission in the world’s only permanent working undersea laboratory recently to study changes along a coral reef off the Florida Keys, with plans to broadcast their dives and research activities over the Internet.
Six “aquanauts” will work, sleep and eat at Aquarius Reef Base, located on the ocean floor about nine miles southeast of Key Largo in Florida Keys National Marine Sanctuary. The base lets researchers dive for nine hours a day and return to the habitat without standard scuba diving requirements of surfacing and decompressing.
Researchers will study sponge biology and the area’s coral reefs, which are fertile marine habitats but face threats that the rest of the world’s reefs also encounter — disease, rising ocean temperatures and human factors such as pollution and overfishing.
The team will bring its research to students with undersea classroom sessions and to the public through Internet video. Feeds will come from both inside Aquarius and from divers wearing helmets mounted with cameras and audio equipment. The goal is to generate interest in science and the oceans among young people.
“It would be ideal if all the students we are going to reach on this mission could actually be here, but the truth is most of them will never get that opportunity,” said Ellen Prager, chief scientist for Aquarius. “So the best we can do is have them connect and be virtually there.”
About 60 feet below the Atlantic, the yellow, tube-shaped Aquarius is 43-feet long and about nine feet in diameter — about the size of a school bus. Owned by the National Oceanic and Atmospheric Administration and operated by the University of North Carolina-Wilmington, Aquarius was built in 1986 and began operating in the U.S. Virgin Islands before being redeployed off Key Largo in 1993. Both the Navy and NASA use the lab for experiments and research.
The facility has bunk beds and showers; a microwave, refrigerator and sink; and the computer and diving equipment needed to research reefs and collect, assemble and relay data. “It’s not claustrophobic, really,” said Prager.
Food, computers and other equipment are sent down using pots that can handle 2 1/2 times normal atmospheric pressure below the ocean’s surface.
“Things tend to taste very bland. There’s a lot of hot sauces down there,” Prager said.
Using a system of cables that stretch out from Aquarius, divers will visit sites they have studied in the past to determine if any long-term change has taken place. They will swim to underwater outposts to refill their tanks and do not have to decompress after dives.
A surface buoy provides air, power and communications to Aquarius through hoses, cords and cables. On land, a crew monitors the living conditions in the facility.
Such work is necessary because the world’s reefs have changed substantially over the past 20 years, said Steve Gittings, science coordinator with NOAA’s Marine Sanctuaries Division.
On most reefs, the abundance of hard coral has declined, and the cover of soft algae has increased, Gittings said. Algae is a natural part of the ocean ecosystem, but it can respond to human influences such as pollution to create large or unnatural concentrations that can displace corals.
Researchers also want more knowledge about two other reef dwellers, sponges and soft corals, because it’s not clear whether their abundance has significantly changed, Gittings said. Also of interest are the suspected causes of change in reef ecosystems, which may include a mass die-off of a long-spined sea urchin that ate algae, or human activities such as pollution, Gittings said.
“We’re seeing dramatic changes literally on reefs around the world with regard to the relationship between all those different components that live on the bottom,” Gittings said.
One of those components is sponges, which pump water through their bodies to filter food particles and produce dissolved nitrogen, a fertilizer.
The Aquarius team will investigate any linkage between changes of reef compositions and organic matter processed by sponges, seeking to discover whether sponges are fertilizing grasses that compete with corals, said researcher Chris Martens of the University of North Carolina at Chapel Hill.
“Corals have gone through huge changes in terms of being totally dominant in oceans to being lesser,” said Martens. “We’re asking the question, ‘Do sponges help or hurt in that process?”’
On the Net:
Virtual Dive to Aquarius: ml
NOAA’s National Marine Sanctuary Program:
Published in The Messenger on 10.11.07

Leave a Comment