|
|
By Phil Williams
pwilliam@franklin.uga.edu
Two UGA ecologists have developed a rapid method of revealing which streams face land-use  pressures and are in urgent need of preservation efforts. The approach could eventually help scientists prioritize certain streams and rivers before development makes conservation efforts more difficult.
Though the method is being developed specifically for north Georgia’s Etowah River system, it could be used for areas with similar topography and climate and make it easier to prevent damage before it occurs.
“Though we have a long way yet to go, this research could point the way to some practical changes in the way we predict and handle the impact of land use on streams, rivers and lakes,” says Seth Wenger, a conservation ecologist and policy analyst in UGA’s Institute of Ecology.
The research, presented at the annual meeting of the Society for  Conservation Biology in Montana in June, is being sponsored by the U.S. Fish and Wildlife Service and the Georgia Department of Natural Resources.
“The stream systems in northwest Georgia contain our most imperiled fishes and mussels,” says Byron Freeman, a research ecologist and expert on Georgia’s river systems. “Several of these counties are among the fastest-growing ones in the nation; thus the heat is on for these species and stream ecosystems.”
The southeastern United States supports considerable aquatic biodiversity, but rapid development is threatening numerous species, including several already identified as threatened or endangered.
The goal of Wenger and Freeman’s study was to develop rapid and inexpensive methods to detect threatened streams, using biological and land-use methods. The study area was the Etowah River system, a tributary to the Coosa River that lies on the fringe of Atlanta’s urban sprawl in north central Georgia.
 A sampling of water-living animals has been used extensively in the past to determine a stream’s health, but that approach alone is not enough to determine threats to a stream. The researchers therefore used a two-tiered approach.
First they employed biotic criteria to come up with sub-basins and stream segments with high biological diversity.
Then they added land-use information, in the form of geographic-information systems coverages, to rank streams in terms of pollution sources, road density, road crossings and dams.
One practical result of the research could be a change in the way the Army Corps of Engineers identifies mitigation sites for development that impacts the character of wetlands and streams.
Under the Clean Water Act, a developer who affects the quality of such areas must find ways to offset the overall damage.
Having a rapid method of finding the most sensitive streams could make the job easier and more accurate.
While the new methods likely won’t work for such areas as the coastal plain and the arid American West, they could work for other piedmont areas where the climate is similar to North Georgia’s.
|
|
