MACROINVERTEBRATE COMMUNITY IN THE LOWER EBRO RIVER (NE SPAIN)

We examine the macroinvertebrate community composition and dynamics in the last 60 km of the Ebro river (NE Spain). Different sampling metho ds (individual stones, Surber, kick samplers and artificial substrate) were used depending on the characteristics of the sites chosen (subst rate, current velocity, saline influence). The high nutrient content a nd the abundance of UFPOM is the origin of a high density in stones al though no clear pattern exists between stone surface area and density or species richness. The high spatial heterogeneity and moderate distu rbance intensity and frequency because of river regulation explains th e relatively rich macroinvertebrate community and the low temporal cha nges in the community.