Effects of Strip Mining Related Disturbance on the Benthic Insect Communities of Selected Streams in the New River Basin of East Tennessee

Four streams in the New River Basin in East Tennessee (one undisturbed and three disturbed) were sampled monthly to determine the effects of contour strip mining for coal on benthic insect communities. In addition to sampling for benthic insects, various physical parameters were measured at the time of sampling to help determine factors that cause changes in benthic community composition in streams disturbed by strip mining. Samples from each stream were analyzed monthly, seasonally, and for the total sampling period to determine effect on the number of species and individuals and on species diversity. For these three factors data were analyzed using analyses of variance, Student-Newman-Keuls means separation tests, and the Shannon diversity index. Benthic communities in the disturbed streams showed significant reductions in species, individuals and diversity with mining disturbance. In order to determine which factors were primarily responsible for determining differences, multivariate discriminant analysis, using both independent and dependent factors, was employed. The variables found to be most discriminating in determining differences among streams were rainfall, stream flow, and turbidity. Three of the seven taxa shown to be discriminating variables in determining stream differences were significantly different between control and disturbed stream.

Results clearly demonstrated the overriding influence of physical factors associated with rainfall and runoff, and resultant increased stream flow on benthic communities in streams disturbed by strip mining activity.