Report on Harmonisation of freshwater biological methods

values for correlated metrics were defined using the mean trend line through allmetric values. If no significant correlation existed scoring criteria were defined usingthe literature. Five integrity classes were defined. The IBI was tested internally bycomparing the IBI scores and the attributed habitat quality scores. A similarcomparison was done using an independent set of data of known habitat quality. Theindividual contribution of the selected metrics was assessed. The developed IBIclearly distinguishes good sites from impacted sites and can separate the heavilyimpacted sites from the fairly impacted. The IBI meets the criteria imposed by theEuropean Water Framework Directive.France123. FBI : Oberdorff et al. (2001) developed a 7 metrics index that can be appliedin different regions and river types of France despite the complex and heterogeneousgeology and climate of this country.Germany124. FiBS: A multimetric method for the assessment of the ecological status ofrivers using fish assemblages (Dussling et al. 2004). The method is based on thecomparison of recent fish samples with reconstructed type specific reference fishcommunities. For that purpose in total 18 metrics were selected, which can becategorized into six ecological quality features as follows: inventory of species andguilds; abundance of species and guilds; age structure; migration (index-based); fishregion (index-based); dominant species (index based).125. The assessment of the ecological river-status with FiBS comprises three steps.In a first step, all metrics are scored according to defined criteria following theapproach of the IBI (Karr, 1981). In a second step, an assessment of each of the sixecological quality features is carried out. Finally, in a third step, the overallclassification of the referring sampling site is performed by an algorithm calculating aweighted average from the six quality features assessed. Since 2004, FiBS is beentested nation-wide.95