![]() ![]() "Although it's known that resources are often exchanged between adjacent ecosystems, what controls the transfer of those resources is a question," said David Garrison, chair of the NSF LTER Working Group. "The results demonstrate the interconnectedness of habitats, and show the value of taking a broad view in doing research."īy traveling from one ecosystem to another, alligators ferry nutrients like nitrogen and phosphorus from place to place in the food they eat and excrete. "But Nifong and Silliman found that freshwater American alligators can and do visit marine areas, and that they play an important role in coastal ecosystems like salt marshes," said Alber. "Scientists often focus studies on organisms that spend a large part of their time in a habitat, and pay less attention to transient visitors," said ecologist Merryl Alber of the University of Georgia, principal investigator of the NSF Georgia Coastal Ecosystems LTER site. Nifong and Brian Silliman of Duke University recently published the results of a study of marine habitat use by alligators in coastal Georgia in the journal Hydrobiologia. "With widespread observations of this behavior and the knowledge that alligators play important ecological roles," said Nifong, "researchers began to question the possible importance of cross-ecosystem alligator movements between freshwater and saltwater environments." Since the late 1800s, however, alligators have often been spotted in salty environments in Southeast coastal areas. "These glands allow their cousins, the crocodiles, to excrete excess salt from marine environments."Īs a result, alligators' use of salty environments such as near-shore marine areas, mangrove swamps and salt marshes was, until recently, thought of as unusual behavior and of little ecological importance. "Historically, alligators have been considered a freshwater species due to their lack of salt-secreting glands," said Nifong. Southeast coastal plain, said ecologist James Nifong of Kansas State University. The American alligator is the most abundant large predator in aquatic ecosystems along the U.S. They move back and forth between marine and freshwater ecosystems to rebalance their salt levels - and to feed. Unlike their relatives the crocodiles, alligators don't have salt glands and therefore can't survive full-time in salt water. The scientists discovered that the amount of time alligators spend in fresh or salt water depends on factors such as tide range and water temperature. and around the world, used radio or GPS transmitters to track alligators' wanderings for as long as four months, placing the instruments on the backs of the 'gators. The transmitters are allowing scientists to learn about 'gator movements between freshwater and saltwater ecosystems.Įcologists at the National Science Foundation (NSF) Georgia Coastal Ecosystems LTER site, one of 28 NSF LTER sites in the U.S. Now transmitters similar to those that track space mission orbiters are being used here on Earth to follow alligators, rulers of the swamps. The sophistication of radio transmitters has moved well beyond the days of walkie-talkies. ![]() Find related stories on NSF's Long-Term Ecological Research (LTER) Program site. ![]()
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