Stream macroinvertebrate response to catchment urbanisation (Georgia, U.S.A.)

• DOI: 10.1046/j.1365-2427.2003.00979.x
• Publication Date: 2003-03-11T21:31:21Z
• Authors: A. H. Roy; A. D. Rosemond; M. J. Paul; D. S. Leigh; J. B. Wallace
• Keywords: Land Cover; Riffle; Biotic index

SUMMARY 1. The effects of catchment urbanisation on water quality were examined for 30 streams (stratified into 15, 50 and 100 km 2 ± 25% catchments) in the Etowah River basin, Georgia, U.S.A. We relationships between land cover (implying use) these catchments (e.g. urban, forest agriculture) macroinvertebrate assemblage attributes using several previously published indices to summarise response. Based a priori predictions as mechanisms biotic impairment under changing cover, additional measurements made assess geomorphology, hydrology chemistry each stream. 2. found strong stream biota. Taxon richness other that reflected good negatively related urban positively cover. Urban alone explained 29–38% variation some indices. Reduced was detectable at c . >15% 3. correlated with number geomorphic variables such bed sediment size (–) total suspended solids (+) well including nitrogen phosphorus concentrations (+), specific conductance turbidity (+). Biotic better predicted by reach scale than single, variables. Multiple regression models 69% taxon 78% Invertebrate Community Index (ICI) phi variability, depth, riffle , respectively. 4. Indirect ordination analysis used describe functional group changes among sites corroborate which environmental most important driving differences assemblages. first axis non‐metric multidimensional scaling highly (slope, conductance, variability; adj. R =0.83) also our multiple models. 5. Catchment resulted less diverse more tolerant assemblages via increased transport, reduced solutes. sensitive richness, EPT ICI. Our results largely consistent over range basin we tested.