Benthic invertebrates as indicators of urban and motorway discharges

Spatial differences in the structure and composition of the invertebrate community of a suburban river (demonstrated by the use of indices) could be explained largely in terms of organic inputs but such indices were not suitable for the detection of the low level metal contamination associated with road runoff. Analysis of plant and animal tissue proved to be a more useful strategy and significant variation in metal concentrations in several organisms could be related to the chemistry of the river water and to road and urban discharges.