Boundary Setting Procedure. The EU-WFD requires the ecological assessment of water bodies to be expressed in the 5 ecological status classes “high”, “good”, “moderate”, “poor” and “bad”. Since all European water bodies have to be protected or enhanced in order to achieve at least “good” ecological status by 2015, the correct classification of a water body is crucial. A misclassification into a lower ecological status class would lead to unnecessary implementation and realization of restoration measures and hence to an avoidable consumption of financial resources of the regional and national administrations in EU member states. On the other hand, can the misclassification into a lower ecological status class lead to a situation where a water body that would actually be in need of restoration efforts is not considered and remains in a poorer status than the good ecological status. We suggest here to use the boundary setting method described for river benthic macroinvertebrates (Intercalibration Common Metric Index (ICMi) from the AQEM/STAR project) in Erba et al. (2009) that is based on the EU Guidance document CIS (2003). Xxxx et al. (2009) defined reference sites in compliance with the EU WFD (Hering et al. 2003, Xxxxxxx et al. 2004, CIS 2003). The 25th Percentile of ICMi values at the reference sites was set as the High/Good boundary and the Good/Moderate (G/M), Moderate/Poor (M/P) and Poor/Bad (P/B) boundaries were defined as 75 %, 50 % and 25 % of the High/Good boundary value, respectively. This classification was then used to validate the class boundaries determined in the intercalibration exercise performed for streams in the Central-Baltic, Alpine and Mediterranean GIGs (Geographical Intercalibration Groups) and the results were in good agreement with the intercalibration class boundaries. The calculated boundary classes for LIMCO and LIMHA (MP = macrophytes, ST = stones, SA = sand) are listed in Table 9. We used in each biogeographical region all sites with the a-priori classification “natural” as reference sites. We then calculated the 25th Percentile as the H/G boundary for LIMCO and LIMHA and derived the G/M, M/P and P/B boundaries according to Xxxx et al. (2009) (see above).
Boundary Setting Procedure. The boundary setting procedure is orientated at the normative descriptions of the WFD (Annex V; 1.2.3). The boundary setting results interpretive based on the normative terms. Because of the high variability of the fish community there are little differences in comparison to the REFCOND suggestions for class boundaries. a) normative description b) assessment/similarity to reference condition c) EQR d) ecological status 1a) ...completely or nearly..., barely differences,
Boundary Setting Procedure. Assumption for species composition: skewed linear relation between quality of the ecosystem and the species composition.
Boundary Setting Procedure. The boundaries were set at the zones of distinct changings of the biocoenosis (macrophytes and phytobenthos), and depending on indicator species lists derived from nutrient dependent TI (diatoms).
