The Water Framework Directive – opportunities and new developments in freshwater conservation
Main goal of the WFD is to reach the "good status" of all European freshwater bodies by 2015. This is defined by the "good ecological status" and the "good chemical status".
Ecological status assessment is based on "Biological Quality Elements" and supported by hydromorphological and chemical parameters.
For rivers and lakes, the relevant Biological Quality Elements are:
Macrophytes (higher plants) and phytobenthos (benthic algae)
Benthic invertebrates (animals living at the river bottom)
This website describes the assessment procedure for the Quality Element "benthic invertebrates".