Uso de invertebrados bentônicos na avaliação da qualidade da água da bacia do Alto Atibaia (SP) / Use of benthic invertebrate in water quality assessment of Atibaia river basin (São Paulo, State)




Due to importance of the use of bioindicators to assess environmental quality and the advantages of employing benthic macroinvertebrates for this purpose, these organisms were used to assess the water quality of the Atibaia river basin (SP) in eight sites: 3 in the Atibainha river, 3 in the Cachoeira river, and 2 in the Atibaia river. Channel, depositional margin and erosional margin were sampled. Three replicates were collected in each habitat using a Hess sampler (678.9 cm2, 500μm mesh) or modified Petersen grab (325 cm2). Sediment samples were collected with a stainless steel modified Petersen grab for analysis of granulometry, humidity and total, volatile and fixed residues. This study is divided in three chapters. In the first, the fauna showed that headwater and downstream reservoir sites of Cachoeira and Atibainha rivers presented lower richness and diversity than intermediate sites. In the sampling sites of the Atibaia river, the fauna responded to the water quality decline, reflecting an environmental gradient. In the second chapter, aiming the utilization of rapid assessment techniques to facility data analysis and interpretation, twenty one biological metrics were applied. Metrics that evidence the environmental gradient of the basin, with restricted variation coefficient, were richness and diversity of families, total density, richness of EPT and ETO, percent of Diptera taxa and noninsects, BMWP “JUNQ” and IBBJ. In the third chapter, aiming to contribute to the development of a rapid assessment monitoring plan for the Atibaia river basin, according to the methodology employed, it was concluded that the erosional margin was the habitat that showed the best correspondence with the average or sum of the sites, at least during the dry season.


biological metrics rios zoobenthos métricas biológicas zoobentos biological assessment amostragem de habitats avaliação biológica rivers habitat sampling

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