Directive Cadre Européenne sur l'Eau, rapport technique : méthodes d'évaluation de l'état écologique des lacs basées sur le phytobenthos

In the Phytobenthos cross-Geographical Intercalibration Group (GIG): 11 Member States (see Table 2.1) submitted their lake phytobenthos assessment methods; Intercalibration (IC) was carried out for three broad common types: high alkalinity (HA), moderate alkalinity (MA) and low alkalinity (LA) lakes; Intercalibration “Option 2” was used for HA and MA types - indirect comparison of assessment methods using a common metrics, while direct comparison was carried out for LA type where only 2 assessment systems were compared; The Trophic Index (Rott et al. 1999) was used as IC common metric, it was benchmark-standardized using “continuous enchmarking” approach; 8 countries participated in HA type intercalibration (HU and PL were excluded from calculation of harmonization ban, but included later), 8 countries participated in MA type intercalibration (FR, IT and DE excluded), 4 countries participated in LA type intercalibration (SE and FI excluded); The final results include harmonised EQRs of BE, DE, HU, IE, PL, SE, SI and UK phytobenthos methods for HA type; BE, FI, IE, SE, UK - for MA type, IE and UK – for LA type.