Case study - the River Danube in Austria
Humpesch, U. H.
A total of 897 species of benthic macroinvertebrates have been recorded in the Austrian stretch of the River Danube. The characteristics of impounded sections of the river are described, using the impoundment at Altenwörth as an example. The spatial and temporal dynamics of benthic macroinvertebrates near the upstream end of the Altenwörth impoundment are described and the influence of four major environmental variables acting singly and in combination on the benthic macroinvertebrates has been analysed. About 30 million animals drift in 24 hours through the cross-section of the river at km 2005, and the proportion of total benthos animals, drifting at any instant in time, ranged from 0.0026 to 0.0064%. As a result of a pilot study, the heterogeneity of the bottom sediment and distribution of macrozoobenthos in the horizontal and vertical planes are described for the first time.