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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Bioassessment: Multimetric Development
THE DEVELOPMENT OF A MACRO-INVERTEBRATE BASED MULTIMETRIC INDEX FOR MONITORING THE ECOLOGICAL STATUS OF RUNNING WATERS IN AUSTRIA.
T. Ofenboeck1, O. Moog1, J. Gerritsen2, and M.T. Barbour2. 1Department of Hydrobiology, BOKU University of Agricultural Sciences Vienna, A 1180 Vienna, Austria, 2Tetra Tech Inc., Owing Mills, Maryland 21117, USA
With emphasis on macro-invertebrates the adoption of the multimetric approach to Austrian rivers has been chosen as a potential assessment measure within the European water framework directive (WFD). The multimetric methodology was established with the following requirements: the ecological status of rivers must be determined on the basis of near-natural reference conditions; ecoregions and bioregions are part of a comprehensive typology of surface waters; selection of reference sites are based on expert opinion; and selection of historical data includes only data of sufficient quality and standardised procedures. For each of the 15 Austrian bioregions an individually composed multimetric index was developed. The indices are based on a fixed set of core metrics with a high discriminatory power in the whole country as well as on specific metrics of regional validity. Basic metrics include species richness, number of EPT taxa, % of shredders and grazers, and a diversity index. Metrics of regional validity include % EPT, longitudinal zonation index, and % Oligochaeta + Diptera. To evaluate the effects of known environmental impairments (e. g. channelization, impoundment, organic pollution) it is recommended to adapt the selection of bioregion specific metrics towards a stressor-specific multimetric index.
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