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 ecologica l integrity, has become a pivotal word within both Austrian water managemen t and limnological research. Incorporated in the most important laws concer ning water management issues, the term ecological integrity reflects the ne cessity of considering water bodies as ecological systems. Although ecologi cal 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 struct ures, flow regime, connectivity), physico-chemical parameters, macroinverte brate and fish assemblages, biological water quality assessment and ecotoxi cological evaluations. The classification is based on the assessment of the se individual criteria by means of a comparison between a river-type-specif ic reference state and the current conditions. This approach, which has bee n 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 asses sing the ecological integrity of running waters, some nation-wide programme s concerning water quality, habitat assessment, and river typology are brie fly presented.