Foz do Areia Reservoir, Brazil: Physical, Chemical and Cyanotoxin Aspects

Abstract

Human development processes govern large changes on the natural environment, one of the biggest are the reservoirs of hydroelectric power plants, transforming the natural environment, leading to changes in natural conditions while other anthropogenic processes accelerate the processes of eutrophication, which may trigger a production of cyanotoxins by cyanobacteria, especially a cyanotoxin Microcystin-LR, a highly dangerous hepatotoxin. The objective of this study was to investigate and evaluate the physical, chemical and cyanotoxins occurrence in the Foz do Areia reservoir. The main parameters of water quality, organic matter and microcystin were investigated, the results analyzed by fator analysis for to raise the main factors influencing phytoplankton production, the relation between the phytoplankton production and the occurrence of cyanobacteria related to the toxin production. Relation between phytoplankton production, the occurrence of cyanobacteria possibly produced by the toxin and the occurrence of intra and extracellular toxin in the monitored sites.  The results showed that a phytoplankton production with a higher incidence of solar radiation and hydraulic operation of the reservoir did not find specific conditioning factors an occurrence of flowering of cyanobacteria without reservoir and a production of the toxin by the microorganisms, as well as the relation between the data The release of the toxin into the external environment.