Biological indicators and assessment methods for the European Water Framework Directive: a framework context, innovative approaches, essential issues

Abstract

The European Water Framework Directive has placed hydrobiology at the heart of the assessment of the quality of aquatic environments. This vision constitutes a strong and logical evolution, in the direction of the path followed in France with the implementation of the first law on water in 1964. This importance given to biology has generated various needs, translated by a strong demand addressed to the scientific world for the development of operational tools that had to meet the new community requirements and the needs of managers. Bioindication has once again become a very active discipline in ecology, supported by strong societal issues. We present here an overview of the different aspects of the context in which biological indicators and assessment methods have been developed, mainly for rivers and estuaries, to show the challenges that this work must face.