Effects Of Land Cover And Riparian Buffers On Cold-Water Fish Assemblages In Upper South Fork New River Headwater Streams

Climate change combined with expanding urbanization and changes to land-use pose a serious threat to many cold-water species as temperature continues to increase. This study focused on the effects of biogeophysical components on cold-water fish assemblages within headwater sub-basins that vary widely in ability to support sensitive and endemic fish species. The relative abundance of cold-water fish were sampled by electrofishing 16 sites during the spring and summer then compared to riparian corridor density and height measurements, the percentage of sub-basin wide impervious surfaces, Bank Erosion Hazard Index (BEHI), Wolman Pebble Count, water temperature, and specific conductivity. The monthly maximum stream temperature did surpass static laboratory determined thermal suitability limits for brook and brown trout; and diurnal fluctuating laboratory determined limits for rainbow trout (20.0-22.5 °C) in 14 sites. However, the regression analyses of riparian heights (R2 = 0.05) and densities (R2 = 0.07) within each sampling reach did not significantly reduce stream temperature between sites. Temperature and conductivity were not found to significantly impact cold-water fish conditions, however; bank erosion, benthic substrate, riparian height, and impervious surfaces did. The relative abundances of cold-water fish were found to increase with the quality of the habitat.