The nematode-fauna (Nemathelminthes, Nematoda) of a polluted part of the river Mur (Styria, Austria)

Abstract

There is no single method that can be used to indicate the chemical and biological quality of fresh water systems. However, Zullini (1976) suggests that non-parasitic nematodes can provide a biological evaluation of running waters, as they are resistant to chemical and organic pollution and occur regularly in different environments. Moreover. the species-composition is sensitive to different levels of organic material and other chemical pollutants in the water. Oligochaetes and protozoa also occur regularly, but nematodes are easier to observe, and to extract and fix for identification. This paper refers to an investigation of the effect of paper mill waste water discharged into the river Mur between Stuebing and Graz on the nematode fauna. During the investigation the mill stopped discharging untreated waste water into the river and introduced a system of mechanical purification before the discharge. About the same time an improvement programme was started for the river Mi..irz, which is the main contributory of the Mur. The effects of these changes are reflected in the changes of the nematode species-composition.