Scientists Study Decline of Local Salamander - The Ozark Hellbender
Associated Press, St. Louis Post-Dispatch
June 16, 2003
Standing on wobbly stones along the North Fork River in Ozark County, Ben Wheeler holds his fingers a few inches apart, a gap big enough to fit one Ozark hellbender, a tiny, young salamander he's hoping to find.
Years ago, hundreds of Ozark hellbenders could be found in every mile of the North Fork River. But in March, the Missouri Department of Conservation declared the hellbender an endangered species in the state.
Older salamanders are not affected as dramatically by environmental factors, said Wheeler, a 29-year-old doctoral student at Arkansas State University. Many of the salamanders - which can live up to 29 years - have been squatting in the same spot for years, feeding on crawfish, snails and worms.
Scientists say the increase in population and land development in the Ozarks has polluted the river habitat of the hellbenders. They consider the hellbender a harbinger for humans because the same pollution that is bad for the salamanders is also bad for humans.
Members of the Hellbender Workshop Group plan to meet in Georgia next month to discuss what they think has caused the hellbenders to go from abundant to nearly absent.
Ron Goellner, director of animal collections and general curator at the St. Louis Zoo, says the salamanders were found throughout the Mark Twain National Forest in the 1970s.
"Any suitable rock had a hellbender under it," Goellner says. "Most streams seemed to have fantastic populations."
Goellner says the first signs of a problem appeared in the late 1980s and early 1990s, when fewer hellbenders were found in the Spring River in northern Arkansas.
However, Conservation Department divers found 150 hellbenders during a two-day survey of southern Missouri streams in 1991.
"The consensus seemed to be that they were doing fine," Goellner says.
By 1998, a study commissioned by the Conservation Department found that nearly 80 percent of the salamanders had vanished, department herpetologist Jeff Briggler says.
Yue-wern Huang, an assistant professor of biological sciences at the University of Missouri at Rolla, says there seems to be a reproductive disruption among the salamanders. However, Huang says he's unsure what is causing a disruption in the hellbender's endocrine system, which regulates the secretion of hormones - although his theories include pollution, pesticides and people as possible causes.
Huang hopes water samples from the North Fork will give him insight into what pollutants might be harming hellbenders.
At Southwest Missouri State University, associate behavioral ecology professor Alicia Mathis is also trying to help keep the salamanders from extinction. Mathis and graduate student Shem Unger are raising both Ozark hellbenders and eastern hellbenders, which live between southern New York and eastern Missouri.
Tests suggest that Missouri hellbenders have lower sperm counts than their counterparts in North Carolina and Georgia, Mathis said. A similar study on humans from Columbia, Mo., Minneapolis, Los Angeles and New York City showed the Missouri men tested had the lowest sperm count.
Mathis says one interpretation of the results is that chemicals in Missouri's streams and rivers have sabotaged reproductive systems in both hellbenders and humans.
"It may be something we should be concerned about," Mathis says.
Whatever is causing the decline, Goellner says he hopes it can be reversed.
"Maybe it could be a very simple set of recommendations to turn it around," Goellner says. "I guess all we can be is optimistic."
Republished with the permission of the St. Louis Post-Dispatch.
Copyright 2004 St. Louis Post-Dispatch
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