Analysis of benthic macroinvertebrates and biotic indices to evaluate water quality in rivers impacted by mining activities in northern Chile

摘要: Catchments in the semiarid regions are especially susceptible to environmental perturbation associated with water scarcity, hydrological variations and overuse by anthropogenic activities. Using multivariate analysis relate biological data, diversity biotic indices (ChBMWP, ChIBF), we analyzed macroinvertebrate composition of 12 rivers region northern Chile. A non-metric multidimensional scaling for taxa a principal component variables strongly separated upstream sites (e.g. Vacas Heladas Malo Rivers), which presented low pH high dissolved metal concentrations, from other sites. Effectively, CCA showed that metals pH, altitudinal gradient, determined distributional patterns macroinvertebrates Elqui catchment. The causes these particular conditions could be related geological processes human impact. applied sampling corroborated reflected characteristics, La Laguna Turbio Rivers showing diverse community moderate good quality, Claro River favorable development aquatic biota, indicating its better quality relative stations. To middle part basin, change was observed, species suggest an impact increase organic matter, due agricultural activities urban settlements concentrated this area. Our results Chile may exceptional species, adapted unfavorable geochemical conditions, emphasize need protection basins region.