TEMPORAL VARIATION AND SPATIAL HETEROGENE ITY OF ZOOPLANKTON FOOD AVAILABILITY IN BACKWATERS AND THE MAIN CHANNEL OF THE RIVER MEUSE (BELGIUM)

The structure the temporal evolution of zooplankton community of two b ackwaters of the River Meuse (the <<noues de Tailfer>> and the <<noue de Waulsort>>) were monitored during spring and summer 1993 and 1996. Crustacean densities were much higher in the Waulsort than in the Tail fer backwater and the main channel of the river. Both backwaters showe d a marked spatial heterogeneity of zooplanktonic densities, particula rly affected by the communications with the River Meuse and the hydrol ogic factors.