INTERCALIBRATION OF ECOLOGICAL STATUS OF RIVERS IN IRELAND FOR THE PURPOSE OF THE WATER FRAMEWORK DIRECTIVE

This paper describes Ireland's participation in the intercalibration of the macroinvertebrate biological quality element as used in the classification of ecological status of Irish rivers under the Water Framework Directive (WFD). An Intercalibration Common Metric approach was used to compare different macroinvertebrate methods in use in 21 countries participating in the two geographical intercalibration groups that involve Ireland-the Northern and Central/Baltic geographical intercalibration groups. The results of the intercalibration exercise for Irish rivers are shown, and comparisons are made between pre-WFD water-quality classifications and the new WFD ecological-status classifications. The existing Irish classification system fitted well with the boundaries established under the intercalibration process. Ireland also participated in successful intercalibrations for the following other elements: diatoms in rivers; lake chlorophyll and lake aquatic macrophytes; benthic macroinvertebrates; phytoplankton biomass (chlorophyll) and bloom frequency; macroalgae; and intertidal seagrass in transitional and coastal waters. The intercalibration results are included in the first intercalibration decision published by the European Commission.