Search

Eleven countries participated in an intercalibration exercise to harmonise diatom-based methods used for status assessment in lakes. Participating countries extended from Sweden and Finland in the north to Italy and Slovenia in the south, and from Ireland in the west to Hungary in the east. Intercalibration followed standard procedures developed for the European Commission which ensures that outcomes of this exercise are compatible with those for other types of biota in both freshwater and marine water bodies throughout Europe. Lakes were divided into low, medium and high alkalinity types for this exercise. However, it was not possible to perform a full intercalibration on the low alkalinity lakes due to the short gradient length and confounding influences of pH and humic substances. Values of the Trophie Index of Rott et al. (1999) were computed for all samples in order that national datasets could all be expressed on a common scale. Not all participating countries had reference sites against which national methods could be standardised and, therefore, a Generalised Linear Modelling approach was used to control the effect of national differences in datasets. These steps enabled the position of high/good and good/moderate status boundaries for all participating countries to be expressed on a common scale and for deviations beyond  0.25 class widths ( 0.05 Ecological Quality Radio (EQR) units, assuming equal distances between all class boundaries) to be identified. Those countries which had relaxed boundaries were required to adjust these to within  0.25 class widths whilst the intercalibration rules allowed those countries with more stringent boundaries to retain these. Despite biogeographical and typological differences between participating countries, there was broad agreement on the characteristics of high, good and moderate status diatom assemblages, and the intercalibration exercise has ensured a consistent application of Water Framework Directive assessments around Europe., JRC.H.1-Water Resources

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.

International audience; A pan-European study permits harmonisation of high/good and good/moderate ecological status boundaries for lakes using benthic diatoms.

International audience; The European Union (EU) Water Framework Directive depends, for effective implementation, on Member States (MSs) agreeing to a concept of the unimpacted “reference” state, which will then provide the “expected” value in Ecological Quality Ratio (EQR) calculations. Reference assemblages of organism groups will, in turn, vary, due to geological, hydrological, climatic, physicochemical and biological factors. Member States tackle this by establishing “types” which share common characteristics. However, for the purposes of ensuring consistent application, broad transboundary types were also established within five Geographical Intercalibration Groups (GIGs, referred to here as “regions”) as part of the EU’s intercalibration exercise. In this paper, we evaluate these types using river diatom assemblages and also provide reference threshold values for two common metrics used in pan-European diatom assessments. A database was assembled, representing 14 EU Member States from Ireland and Portugal in the West, to Estonia and Cyprus in the East, in order to explore biogeographical patterns in assemblages unaffected by anthropogenic pressures. Multivariate analyses were used to examine this pattern and its relationship with geographic, typological and abiotic parameters. After taxonomic harmonisation, NMDS ordination of samples indicated weak differences in assemblage composition among regions. ANOSIM analyses, in turn, indicated that MS was the best factor to group similar samples whereas alkalinity, recognised as the primary environmental variable structuring diatom communities, although significant, explained less variability in the dataset. This, we believe, reflects the importance of methodological factors other than taxonomy (e.g. counting protocol, sample season) that may be constant within a MS but which vary between MSs. When two diatom metrics, the TI and IPS, were applied to the data, differences in the distribution of the metric scores between MS were generally not statistically significant even though some differences between regions were apparent. A trend of increasing values of TI (decreasing values of IPS) was observed in the sequence: Nordic < Alpine < Mediterranean < Central-Baltic < Eastern Continental regions. Additionally, some differences were observed among types within the Mediterranean and Nordic regions, though not for other regions. The data used in this exercise provides us with a region and, in some cases, a type specific benchmark dataset against which national reference data can be compared.

International audience; In 2009, seventeen analysts participated in a pan-European diatom ring-test (intercalibration), analyzing nine samples from seven countries following the European standard EN 14407. The objective of this exercise was to agree on practical conventions on diatom identification to facilitate future intercalibration work and to assess the extent to which national differences in sample analysis (counting protocol and identification conventions) contribute to variability in EU-level comparisons of diatom-based methods. Differences in the reported taxa lists were large, but not a major source of variation in values of a common metric (the phytobenthos Intercalibration Common Metric, ICM). Therefore, every country can apply its own identification conventions for national assessments, and still be fairly confident that the ICM reflects the national classification of its streams. Part of the index variation was due to differences in counting protocols and care should be taken when handling broken valves, girdle views and small taxa. More work at both national and European level is needed to provide a harmonized way of using diatoms for ecological status assessments in the future.

As part of the WFD implementation, Member-States must intercalibrate their ecological status evaluation systems in the context of geographical intercalibration groups (GIGs) working in comparable natural biogeographic zones and driving exercises targeted at the same typologies of watercourses (mainly based on integrated surface of the watershed at the survey site, mineralization of water and, if necessary, on altitude criteria). Phytobenthic assessment methods of the Central-Baltic GIG watercourses had been subjected to a first intercalibration cycle which was completed in 2007. Since that date, specific work has been carried out through the ECOSTAT Group in order to clarify and improve the criteria used for the validation of reference sites at the European level. That work could have changed the appropriate reference level to be retained by national watercourse type and, at the same time, the level of deviation from the appropriate reference used to establish the Ecological Status of European rivers. Therefore, it was considered necessary to renew the previous intercalibration work, following the revision of criteria for reference sites validation, by conducting a second round intercalibration involving 14 member states, or member states administrative areas using different evaluation systems. The present document is the final report of the 2nd "Central-Baltic" GIG Intercalibration Round for Rivers, currently submitted to E.U. validation.; Dans le cadre d'application de la DCE, les Etats-Membres doivent intercalibrer leurs systèmes d'évaluation de l'état écologique, dans le cadre de groupes géographiques d'intercalibration (GIGs) permettant de travailler sur des zones biogéographiques naturelles comparables, et dans le cadre d'exercices ciblés sur les mêmes typologies de cours d'eau (essentiellement basés sur la surface intégrée du bassin versant au site, la minéralisation de l'eau et, si nécessaire, sur des critères d'altitude). Les méthodes d'évaluation phytobenthiques des cours d'eau du GIG Central-Baltique avaient fait l'objet d'un premier cycle d'intercalibration qui s'est achevé en 2007. Depuis cette date, un travail spécifique a été mené sous l'égide du Groupe ECOSTAT pour préciser et améliorer les critères servant à la validation des sites de référence au niveau européen. Ces travaux ont pu changer le niveau de référence adéquat à retenir par type national de cours d'eau et, du même coup, le niveau d'écart à la référence adéquate servant à établir l'Etat Ecologique. De ce fait, il a été jugé nécessaire de renouveler les travaux d'intercalibration, suite à cette révision des critères de validation des sites de référence, par la réalisation d'un 2ème Round d'intercalibration auquel ont participé 14 Etats-Membres ou zones administratives différentes d'Etats-Membres utilisant un système d'évaluation différent. Le présent document constitue le rapport final du 2ème Round d'intercalibration des cours d'eau du GIG Central-Baltique, soumis à l'U.E. et actuellement en cours de validation.

As part of the WFD implementation, Member-States must intercalibrate their ecological status evaluation systems in the context of geographical intercalibration groups (GIGs) working in comparable natural biogeographic zones and driving exercises targeted at the same typologies of watercourses (mainly based on integrated surface of the watershed at the survey site, mineralization of water and, if necessary, on altitude criteria). Phytobenthic assessment methods of the Central-Baltic GIG watercourses had been subjected to a first intercalibration cycle which was completed in 2007. Since that date, specific work has been carried out through the ECOSTAT Group in order to clarify and improve the criteria used for the validation of reference sites at the European level. That work could have changed the appropriate reference level to be retained by national watercourse type and, at the same time, the level of deviation from the appropriate reference used to establish the Ecological Status of European rivers. Therefore, it was considered necessary to renew the previous intercalibration work, following the revision of criteria for reference sites validation, by conducting a second round intercalibration involving 14 member states, or member states administrative areas using different evaluation systems. The present Volume 2 contains the appendices of the final report of the 2nd "Central-Baltic" GIG Intercalibration Round for Rivers, currently submitted to E.U. validation.; Dans le cadre d'application de la DCE, les Etats-Membres doivent intercalibrer leurs systèmes d'évaluation de l'état écologique, dans le cadre de groupes géographiques d'intercalibration (GIGs) permettant de travailler sur des zones biogéographiques naturelles comparables, et dans le cadre d'exercices ciblés sur les mêmes typologies de cours d'eau (essentiellement basés sur la surface intégrée du bassin versant au site, la minéralisation de l'eau et, si nécessaire, sur des critères d'altitude). Les méthodes d'évaluation phytobenthiques des cours d'eau du GIG Central-Baltique avaient fait l'objet d'un premier cycle d'intercalibration qui s'est achevé en 2007. Depuis cette date, un travail spécifique a été mené sous l'égide du Groupe ECOSTAT pour préciser et améliorer les critères servant à la validation des sites de référence au niveau européen. Ces travaux ont pu changer le niveau de référence adéquat à retenir par type national de cours d'eau et, du même coup, le niveau d'écart à la référence adéquate servant à établir l'Etat Ecologique. De ce fait, il a été jugé nécessaire de renouveler les travaux d'intercalibration, suite à cette révision des critères de validation des sites de référence, par la réalisation d'un 2ème Round d'intercalibration auquel ont participé 14 Etats-Membres ou zones administratives différentes d'Etats-Membres utilisant un système d'évaluation différent. Le présent Tome 2 contient les annexes du rapport final du 2ème Round d'intercalibration des cours d'eau du GIG Central-Baltique, qui a été soumis à l'U.E. et qui est en cours de validation.

This technical report present the result from the inter calibration of the fish assessment method for the ecological status of the transitional waters., Ce rapport présente les résultats de l'intercalibration des méthodes d'évaluation de l'état écologique des eaux de transition basé sur les indicateurs poissons développé par chaque état membre de l'UE.

International audience; The European Union (EU)'s Water Framework Directive (WFD) requires that all Member States participate in intercalibration exercises in order to ensure that ecological status concepts and assessment levels are consistent across the EU. This paper describes one such exercise, performed by the countries in the Central/Baltic Geographical Intercalibration Group stretching from Ireland in the west to Estonia in the east and from the southern parts of Scandinavia to the northern regions of Spain and Italy (but excluding alpine regions, which were intercalibrated separately). In this exercise, methods used to measure ecological status of rivers using benthic diatoms were compared. Ecological status is estimated as the ratio between the observed value of a biological element and the value expected in the absence of significant human impact. Approaches to defining the 'reference sites', from which these 'expected' values were derived, varied from country to country. Minimum criteria were established as part of the exercise but there was still considerable variation between national reference values, reflecting typological differences that could not be resolved during the exercise. A simple multimetric index was developed to compare boundary values using two widely used diatom metrics. Boundary values for high/good status and good/moderate status set by each participant were converted to their equivalent values of this intercalibration metric using linear regression. Variation of ±0.05 EQR units around the median value was considered to be acceptable and the exercise provided a means for those Member States who fell significantly above or below this line to review their approaches and, if necessary, adjust their boundaries.