Effects of land use on water quality and macroinvertebrateassemblages in the southern inner piedmont ecoregion of Georgia,USA

Watersheds in Georgia are subject to alteration and contaminant input due to the diverse land uses in this state. Targeted land uses include residential, urban, poultry production, livestock, row crop agriculture, and unaltered forest. In this study, ten streams were assessed, consisting of a habitat assessment, macroinvertebrate collections, and water and sediment sample collections for analysis of heavy metals, organics, nutrients and various other water quality parameters. Elevated nutrient concentrations were measured at agricultural sites and increased specificconductance was measured at urban sites. Trace organochlorine pesticides and heavy metals were detected at every site, with polyaromatic hydrocarbons as the only contaminants unique to a specific land use, urbanization. Hierarchical linear models and non-parametric Spearman rank correlations indicated that urban land use and habitat quality determined by the cumulative habitat score were the best predictor variables describing the changes observed in macroinvertebrate assemblages in the streams.