Effect of sediment quality on benthic macroinvertebrate communities in streams in the north of France

The Nord/Pas-de-Calais region located in the North of France has been submi tted, for several decades, to important pollution due to intensive industri alization. The present study reports on the effects of the metal and organi c content of sediments in different streams on the benthic fauna, using mul tivariate analyses (PCA, CA, co-inertia analysis). Benthic macroinvertebrat e communities present different assemblages along the Canal a Grand Gabarit and the river Aa, both in its natural and in its canalized stretches. Thes e differences are more specifically due to anthropic factors such as the re gulation of waterways and urban and industrial contamination. Go-inertia an alysis enables to bring to the light the existence of a significant co-stru cture between environmental and faunistic data.