Occurrence and Toxicity of Cyanobacterial blooms in Paraná River (Argentina), downstream of the Yacyretá reservoir

FORASTIER MARINA E.; ZALOCAR DE DOMITROVIC YOLANDA; SEDAN DANIELA; ANDRINOLO DARIO

Istanbul, Turkey

Congreso; 8th Internacional Conference on Toxic Cyanobacteria (ICTCH); 2010

The Paraná river basin is the second largest catchment of South America, shared by Brazil, Bolivia, Paraguay and Argentina. The construction of Yacyretá on High Paraná, one of the largest impoundments built in Argentina, was finished in 1990-1994. The first bloom of Microcystis aeruginosa (Kütz) was registered in summer 2004 (Kütz in the river Paraná) In this work we present a study of abundance and toxicity of blooms of M. aeruginosa 220 km downstream from the Yacyretá reservoir (27º28´16"S; 58º51´07"O) between 2004 and 2008.The analyses of the samples showed hepatotoxicity in the tests with mice. Five variants of microcystins were detected: LR, LA, RR, YR and XR. LR was better represented every year in concentrations between 3 and 185 ppm of lyophilised cells. This is the first report of microcystins in the Paraná river (Argentina) during blooms of M. aeruginosa.