Spatial and temporal variation in the macroinvertebrate community structure of the lower Elands River, Mpumalanga, South Africa

Abstract

The Elands River, Mpumalanga, is an ecologically sensitive river that is constantly threatened by a variety of human activities. The influence of a pulp and paper mill on the river's macroinvertebrate assemblages was studied in March and June 2005, representing high- and low-flow seasons, respectively. Macroinvertebrates were collected from various biotopes using a standard sampling net, and were preserved and identified to family level. A range of multivariate and univariate statistical analyses was applied to assess the spatial and temporal variations in the macroinvertebrate communities. Diversity loss and dominance by a single taxon, Melanoides tuberculata, were noted directly below the mill. Other sites did not appear to be affected. Macroinvertebrate communities at all sites showed a strong seasonal variation.