Pollution effects by heavy metals on the benthic community of the Cululu stream basin (Salado river of the north, Argentina)

The incidence of industrial effluents with heavy metals in the physical and chemical quality of bottom sediments of the Cululu stream basin was determined through the analysis of macrozoobenthic community structure. In three seasonal samplings, six environments of the lower section of the Salado river basin of the north were studied, making physical and chemical analysis of bottom sediments, organism density and richness, species diversity and similarity between communities. Relations between macrozoobenthic community structure and composition, environmental variables and heavy metal concentrations (Cr T, Cr VI, Cu, Cd y Pb) in bottom sediments could be established. The reference site had a community with greater density and a different assemblage of species than the ones of the polluted sites. Heavy metals acted as disturbing factors, determining that the macrozoobenthic community of polluted sites were different from one of a reference site.