Impacts biologiques des pollutions sur un ruisseau périurbain : Le Peugue (Gironde)

Biological impacts of pollution on a suburban little stream: the Peugue

Cemagref, Division Qualité des Eaux

Abstract

CEMAGREF is involved in the reasearch program of the GARIH (Regional group for hydrological research), devoted to the pollution fluxes resulting from rain-water, and the means to reduce them.

Cemagref is studying the Peugue, a suburban little stream near Bordeaux. The aim of this work is to characterize the river in situ, so as to specify the impacts of suburban pollutions linked with rainy periods on the environment, and to assess the effects of the forthcoming urban planning. Physico-chemical parameters and specific pollutants (heavy metals...) are measured on monthly spot samples from 11 stations all along the 6 km of the streamlet. Two of these stations are equipped with automatic samplers that give hourly samples to study the dynamics of pollutants during the floods.

The comparison of the chemical analysis with the distribution of macrophytes and diatom communities should lead to demonstrate the impact of different pollutions (ponctual or diffuse) existing on the catchment area. The first investigations enabled us to locate particular pollution sources and to closely connect the results of water analysis with diatom indices commonly used in France for the assessment of water quality.