GLOBAL INFLUENCE OF PHYSICAL HABITAT PARA METERS ON BENTHIC INVERTEBRATES IN TROUT STREAMS - TOWARDS AN INTEGRATION IN FISH HABITAT MODELS/

The influence of physical habitat parameters on macroinvertebrate dens ities and biomass was tested to further develop global suitability cur ves, in order to integrate food-producing zones in fish/habitat models . The database contains 371 samples taken from 28 trout stream referen ce sites in France. Substrate diameter and structure significantly inf luenced densities and biomass. Values were lower on cobbles than on bo ulders, but sandy substrates did not differ from both. Velocity and de pth significantly influenced density. Densities increased with velocit y, but a minimum value occurred at 60-70 cm/s. Densities decreased wit h depth. Differences between observed patterns and existing curves are discussed.