Assessing effects of land use on streams along the Natchez Trace Parkway using rapid bioassessment protocol techniques

Stream quality along the Natchez Trace Parkway was evaluated by hydrologic unit code 4 (HUC4) watersheds and habitat assessment scores as a broad and local scale, respectively. Water chemistry parameters and rapid bioassessment techniques for habitat and fish and invertebrate communities were sampled in 18 streams and six HUC4 watersheds. Forest, agriculture, and developed land use had little variation at HUC4 level; land use impacts could not be determined. Turbidity and TSS were important factors determining habitat scores and created a "boundary" separating southern and northern watersheds. A latitudinal trophic shift was observed of fish omnivore-insectivore-piscivore in southern watersheds to generalist-insectivore-herbivore species in northern watersheds. Fish families were correlated significantly to the water chemistry matrix. Fish species were correlated significantly with the habitat matrix using Canonical Correspondence Analysis. Management implications differ considering the function of these two scales. Only turbidity and percentage cobble substrate were significant at both scales.