The Austrian way of assessing the ecological integrity of running waters:: a contribution to the EU Water Framework Directive

The term 'Oekologische Funktionsfaehigkeit', synonymously used as ecological integrity, has become a pivotal word within both Austrian water management and limnological research. Incorporated in the most important laws concerning water management issues, the term ecological integrity reflects the necessity of considering water bodies as ecological systems. Although ecological integrity of running waters is and must remain a holistic concept, the current Austrian methodology aims at assessing it by investigating a number of key components: hydromorphological aspects (particularly habitat structures, flow regime, connectivity), physico-chemical parameters, macroinvertebrate and fish assemblages, biological water quality assessment and ecotoxicological evaluations. The classification is based on the assessment of these individual criteria by means of a comparison between a river-type-specific reference state and the current conditions. This approach, which has been laid down in the Austrian Standard M 6232 'Guidelines for the ecological study and assessment of rivers', also meets the general requirements of the classification of the ecological status of running waters discussed in the EU Water Framework Directive. Besides describing the Austrian way of assessing the ecological integrity of running waters, some nation-wide programmes concerning water quality, habitat assessment, and river typology are briefly presented.