Division Water category Rivers Geographical Intercalibration Groups All Biological Quality Element Fish fauna

Overview of regional groups that have been established for the river fish intercalibration:

Lowland-Midland group  — Belgium (Flanders), Belgium (Wallonia), France, Germany, Netherlands, Lithuania, Luxembourg, United Kingdom (England and Wales), Poland, Latvia, Estonia, Denmark, Hungary

Nordic group  — Finland, Ireland, Sweden, United Kingdom (Scotland and Northern Ireland), Norway

Alpine-type Mountains group  — Austria, France, Germany, Slovenia, Italy

Mediterranean South Atlantic group  — Portugal, Spain, Italy, Greece, Bulgaria

Danubian group  — Czech Republic, Romania, Slovakia, Bulgaria