Abstract

*Ayrton E. Fernando, Morena V. Gisele and Daniel Campos Santoro

Current analysis, involving measurements of biotic and abiotic factors, determined which factor favored cyanobacteria with subsequent concentrations of microcystins in water collected from a public water supply source during the dry and rainy periods and which received residual water from agricultural production systems. Since no microcystins were detected, waters fitted within the maximum limits of 1g.L-1for MC-LR. Nevertheless, if aquiculture produ1ction systems are not properly administered, especially for the diet factor, great risks will exist in the contamination and pollution of fresh water. This fact may cause intoxication to the population that use the water and to the aquatic plants and animals which make it their habitat.