Bio-indication and fish assemblage in watercourses: a functional and predictive approach

Abstract

Recently, new methods for the assessment of rivers based on the response of fish assemblage to human alterations have been developed at the national and European scales. The original approach developed in the US (Index of Biotic Integrity) has been improved in order to consider the natural environmental variability and to quantify the biological response as a deviation from an explicit reference condition. The aim of this article is to briefly present the principles of the method used in France in the development of bio-indication tools based on fish assemblage in watercourses, to summarise the different conceptions underlying the definition of reference conditions and finally to discuss the points that are still being developed.