Fish Community Response to Natural Landscapes and Anthropogenic Stressors: Application of Biological Condition Gradients in West Virginia Watersheds

Fish community data from 2000 to 2011 were compiled statewide in WV in order to evaluate fish community response to natural landscape features (ecoregion, drainage basin, and network position) as well as anthropogenic stressors (land use and instream water and habitat quality).  Important goals of this study were to determine whether land use/land cover was an effective predictor of fish community structure when accounting for spatial and geographic location and to quantify reliable stressor-response functions.  We evaluated stream condition using Index of Biotic Integrity metrics as well as multivariate ordination and compared these measures to landscape and water quality following a Biological Condition Gradient approach.  The Biological Condition Gradient is a descriptive model that describes how ecological attributes change in response to increased levels of stressors.  Our results indicate that fish assemblages were simultaneously influenced by broad geographic factors and local stressors.  Fish community response to anthropogenic stress, however, was highly variable across the state.   Nevertheless, in several regions of the state we observed strong threshold responses by fish assemblages to stressor gradients such as conductivity.   This research is an important step towards development of fish assemblage based criteria for defining stream impairment in West Virginia.