Benthic macroinvertebrates are an important indicator of river health. However, their response upon water quality development
downstream the pollution outlets considerably depends on the environmental habitat characteristics. Three successive stretches,
each of them providing three different mesohabitats in stillwater (S), torrential (T) and riparian (R) zones were selected
for evaluation of the impact of altered metapotamal river bed morphology (channelization) and chemical determinants of water
quality on the Upper Elbe River. In downstream direction, the stretches are separated by weirs and characterized as a low
polluted low modified natural stream (N), a low polluted channelized stream (C) and a channelized polluted stream (CP). Altogether,
111 benthic macroinvertebrate taxa were recorded in the Pardubice hotspot between Němčice and Přelouč. Despite different levels
of stream bed and water quality degradation, micro- and mesohabitat characteristics appeared to be the most important factors
determining the diversity of macrozoobenthos in riffle (substrate size structure) and in shoreline (macrophyte community composition
and structure) mesohabitats. The diversity of macroinvertebrate communities was highest in riparian mesohabitats compared
to stillwater and torrential ones. Saprobic indices increased in downstream direction, thus indicating the decline of water
quality.
Key words macrozoobenthos - pollution - channelization - degradation - the Elbe River