Towards ecohydrological approach of biomonitoring in running waters

The biomonitoring of aquatic life by traditional tools (qualitative indices) is more than 60 years old. These traditional tools are still developed and routinely used, particularly for the European WFD implementation which needs such cheap methodologies based on simple taxonomical identifications, and being likely shared by the greatest numbers of partners. More modern conceptual frameworks and functional methodologies were developed during the 1970s and 1980s, including production studies, but did not receive enough attention. The abuse of traditional concepts and methods leads to significant conceptual and methodological impoverishments in freshwater biomonitoring. A new multi-disciplinary ecohydrological approach, based on a functional conceptual framework (EASY concept, harmonization system), functional tools (functional traits, riverscape types), and a research management guidance, is proposed. Its development is discussed, demonstrating that it is possible to conciliate innovation and routine application, particularly when rehabilitation or restoration actions are planned.