Summary
Investigations of the occurrence of saprophytic and faecal coliform bacteria at different depths in sediments were made to get fundamentals for using bacteriological sediment data also to describe the hygienic status of water quality. In 1987/1988 the numbers of saprophytic and faecal coliform bacteria were investigated in 54 vertical profiles (6 per month) at the sampling point stream-km 1984, 20m from the right bank, in the impoundment Altenwörth of the River Danube. The samples were taken by a multicorer; the method used was the membrane filtration technique. The numbers of both types of bacteria decreased significantly within the first centimeters of the sediment profile. Therefore it seems necessary to standardize the sampling depth for sediment investigations when results are applied to water quality systems.