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CAS biologist tags marine life, finds coral reefs in peril
By Brian Fitzgerald
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Les Kaufman Photo by Fred Sway |
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A BU celebrity sighting — in a September Boston Herald column usually reserved for Hollywood luminaries? True, Les Kaufman's appearance in the newspaper played second fiddle to a Jennifer Lopez–Ben Affleck wedding rumor, but the CAS professor of biology is still pleased.
“People told me they saw my name in the paper, right under an item on J. Lo,” he laughs. Although Kaufman is used to seeing his name in peer-reviewed journals, the reason for his brief sparkle among the Tinseltown glitterati was his research on a coral reef in the Florida Keys, where he scuba dived for 10 days in August, surgically implanting electronic acoustic tags into fish while underwater, to track their whereabouts.
While Kaufman's tiresome work may not have been as titillating as the Bennifer buzz that dominated the Herald page, he is happy when any study of aquatic biological diversity gets mainstream media attention because indigenous species of fish off the Florida coast are rapidly declining, and so are coral reefs. In his latest mission down south, Kaufman studied both the fish and the coral itself.
Taking a fish census, Kaufman worked with his former grad student James Lindholm (GRS'95, '99), a scientist with the National Marine Sanctuary Program at the time, Greg Stone, vice president of the New England Aquarium's global marine programs, and members of the National Oceanic and Atmospheric Administration (NOAA) Aquarius undersea laboratory. They used underwater transmitters and receivers to gather information about conditions in the Florida Keys National Marine Sanctuary, one of a growing number of marine protected areas (MPAs) established by NOAA and the Department of the Interior. These sanctuaries are recognized as an important management tool for the conservation of marine wildlife populations.
“We wanted to know to what extent the no-fishing zones within the Florida Keys National Marine Sanctuary are effective — which kinds of fish tend to accumulate there, and how often they swim in and out of their safe zones,” says Kaufman. “The primary species we targeted were yellowtail snapper and black grouper. We also tagged blue parrot fish, hogfish, and Spanish hogfish. My compadres even conned a moray eel and two nurse sharks into eating tags hidden in bait.”
Before diving, Kaufman strapped on a tank equipped with Nitrox, a gas mixture that increases the amount of oxygen in the lungs, enabling a diver to spend a significant amount of time underwater — up to six hours a day — without the risk of decompression sickness, also known as “the bends.”
In one of the world's largest acoustic fish tracking networks, Kaufman and colleagues tagged 80 fish with specially coded pingers, ranging from just over a centimeter to several centimeters in length, to monitor their movements over the next year. At the end of each day, some of the other divers retired to the Aquarius, a 12-foot-by-43-foot submarine laboratory that rests 60 feet underwater 3.5 miles offshore. Kaufman had stayed on the Aquarius during two previous missions, “living where the action is,” he says. However, this time, after his day's diving was done, he headed to a nearby laboratory ashore, staying in contact with Aquarius scientists through a video broadcast. The cramped “space station of the deep” is ideal for studying marine life on the ocean's bottom, but during this trip, Kaufman says, he was grateful to “be able to take a hot shower after diving, and go out to a restaurant in the evening,” instead of facing the rudimentary sanitation and freeze-dried food provided on the Aquarius.
Piscatorial wanderlust
“We wanted to see how well this experimental conservation tool — the no-fishing area — is working,” Kaufman says. “We were looking at species to determine if they were hanging out in the protected zone longer than in other places, possibly because there might be more prey there now,” and because one of their chief predators, Homo sapiens, wasn't hunting them. He says that preliminary data so far is “a bit surprising. The species that we thought would stay put went all over the place, and the fish that we thought would go all over the place stayed put. The yellowtail snapper turned out to be a real homebody, and the black grouper wandered in and out far more than we expected.”
Another Kaufman experiment, in collaboration with the Lamont Doherty Laboratory at Columbia University, involved isolating coral in acrylic domes at the ocean bottom and injecting seawater laced with carbon dioxide in the chambers through a rubber gasket, and then monitoring the results. “Coral reefs are in decline everywhere, and elevated carbon dioxide is one of the contributing factors,” he says. It is estimated that more than half of the world's reefs have been severely damaged or lost entirely, largely because of global warming associated with rising sea temperatures and the amount of carbon dioxide in the water. Kaufman says that a full 30 percent of the reefs could be gone within the next 10 to 20 years.
“We're trying to show how increased levels of carbon dioxide disrupt the way corals build their calcium carbonate skeletons,” he says. “Elevated carbon dioxide is a grievous problem for all marine organisms that make shells out of calcium carbonate, including clams, lobsters, and shrimp.”
Using cutting-edge research, these two experiments together will help scientists monitor the status of fishery resources in the Florida Keys. Although the reefs there have been dwindling, Kaufman nonetheless remains upbeat. “Scores of scientists, government bureaucrats, sport divers, fishermen, and other citizens are contributing their time, effort, money, and sweat to help gather information about the condition of the undersea world off the Florida coastline,” he says. “This information will tell us if conservation methods now in place are working, and whether more of the same measures — or different ones — are necessary.”
9
January 2004
Boston University
Office of University Relations