The application of an index of biotic integrity and macroinvertebrate sampling to assess water quality in urban streams

Seven streams in Knoxville, Tennessee, were sampled from May 11 to May 22, 1992, using an index of biotic integrity (Karr 1981; Karr et al. 1986) methodology and quantitative and qualitative macroinvertebrate sampling. Primary in this study was the establishment of some measure of community effects caused by chronic environmental degradation. Application of the index of biotic integrity (IBI) resulted in scores ranging from 30 (Poor) to 44 (Fair) reflecting conditions in Third and First creeks, respectively. Suppressed scoring in total number of expected taxa, number of darter species, proportion of specialized insectivores, and high rates of disease, lesions, and parasitic infestations indicated an imbalance in community structure. Fish samples were dominated by blacknose dace, stonerollers, and creek chubs. Macroinvertebrate samples supported the findings of the IBI with very low species diversity, dominance by pollution tolerant taxa, and loss of sensitive taxa. Samples were dominated by dipteran midges (Chironomidae) and tubificid oligochaetes. Degradation of habitat and water quality continue to suppress both fish and macroinvertebrate communities.