Is chemical contamination linked to the diversity of biological communities in rivers?

We present an overview of possible links between chemical contamination and the diversity of fluvial communities, in order to assess how conventional and more recently developed methodologies used to estimate the diversity of rivers and streams could be used to explore this relationship. We analyze different trophic levels (bacteria, autotrophic biofilm, benthic macroinvertebrates and fish) and discuss their usefulness in diversity-related studies. We present some practical examples of their application. We strongly recommend that future research should involve a multi-index approach and multidisciplinary studies that integrate chemical and biological analyses to assess effectively the relationship between biological diversity and chemical contamination.