SPATIAL VARIATION OF TROPHIC STATUS AND PHYTOPLANKTONIC BIOMASS IN ITUPARARANGA RESERVOIR (SÃO PAULO, BRAZIL)

Abstract

Nowadays the Brazilian reservoirs has suffered great pressure due to increasing demand for water for diverse purposes, being one of the largest eutrophication problems caused by man. The Itupararanga reservoir provides environmental services to more than one million people and is one of the main sources of the Sorocaba River basin and middle Tietê. Thus this study aimed to determine the spatial variability of the trophic level and phytoplankton biomass in the reservoir, as well as the concentrations of nutrients and also check your environment according to CONAMA 357/2005 (BRASIL, 2005). For this, a collection that was conducted in six sampling stations and the measures of pH, conductivity, dissolved oxygen, water temperature, water transparency, total phosphorus, total phosphorus, dissolved nitrite, nitrate, chlorophyll-a and sediment size analysis . The results indicated that there was no spatial variation of the degree of trophy in the Itupararanga reservoir, but there was spatial variation of nutrient concentrations and chlorophyll-a, corroborating theoretical models of reservoir compartmentalization.