Benthic Macroinvertebrate Communities of the Canal À Grand Gabarit, Aa River, and the Canalized Aa River in the North of France

ABSTRACT Using artificial substrates, we surveyed die benthic macroinvertebrate fauna of the Canal a Grand Gabarit, the Aa river, and the canalized Aa River in the Nord/Pas-de-Calais region in France. Low invertebrate diversities were apparent and seem to be related to the presence of heavy metals and organic pollution of the waterway.