The EU WFD calls for a type-specific assessment of fish stocks according to five classes. In order to fulfill this requirement, the Department of Water Ecology has developed an evaluation scheme for the ecological status of fish. This Fisch Index Austria is laid down by ordinance as a national assessment scheme for Austria, with the exception of the assessment of heavily modified water bodies.
Further information on this topic can be found in the publication, available in German only:
Haunschmid et al (2006): Erstellung einer fischbasierten Typologie österreichischer Fließgewässer sowie einer Bewertungsmethode des fischökologischen Zustandes gemäß EU-Wasserrahmenrichtlinie
