Acidic Deposition and the Status of Virginia’s Wild Trout Resource:  Revisited

Wild Trout VII, Yellowstone National Park, October 2000

J.R. Webb, F.A. Deviney, Jr., B.J. Cosby, A.J. Bulger, J.N. Galloway

Department of Environmental Sciences
University of Virginia
Charlottesville, Virginia 22903

Survey-Resurvey: 1987-2000

The initial VTSSS survey was conducted in late April 1987 when stream water samples were collected from 394 brook trout streams in western Virginia. A resurvey was conducted 13 years later in late April 2000 when samples were collected from 452 streams. Of the streams sampled in 2000, 326 were also sampled in 1987. Here we compare differences in sulfate concentrations and ANC for stream sites sampled in both surveys. This comparison is preliminary, pending evaluation and possible adjustment for effects of stream flow and other sources of transient variation.

Comparison of Sulfate and ANC Concentrations for Stream Sites Common to Both Surveys

Palmer Drought Severity Index

The 1987 survey was conducted during relatively wet conditions; the 2000 survey was conducted during a period of relatively dry conditions.