CECOAL   02625
CENTRO DE ECOLOGIA APLICADA DEL LITORAL
Unidad Ejecutora - UE
artículos
Título:
Occurrence and toxicity of Microcystis aeruginosa (Cyanobacteria) in the Paraná River, downstream of the Yacyretá Dam (Argentina)
Autor/es:
ZALOCAR , Y.; FORASTIER, M.E.; DOMITROVIC, H.A.; ANDRINOLO, D.
Revista:
REVISTA DE BIOLOGíA TROPICAL
Editorial:
REVISTA DE BIOLOGIA TROPICAL
Referencias:
Lugar: Turrialba; Año: 2016 vol. 64 p. 203 - 211
ISSN:
0034-7744
Resumen:
Cyanobacteriaconstitute the main toxins producers in inland water ecosystems and showingextensive global distribution. Presence and identification of hepatotoxicmicrocystins in rivers and reservoirs around the world has been confirmed byseveral studies during the last years. The presence of hepatotoxins in aquaticenvironments are hazardous to human and animal health. Herein, we studied theabundance and toxicity of Microcystis aeruginosa (Kütz.) Kütz. in Argentinesection of the Paraná River at the beginning of the Middle Paraná (CorrientesHydrometer), near Corrientescity (27º28´ S-58º51´ W) and approximately 220km downstream of the Yacyretá dam(High Paraná). The Paraná River basin, with a drainage area of 3.1 x 106km2 and3 965km in length, is the second largest catchment of South America, after that of the Amazon. Paraná River is the main source of drinking water supply for theNortheast Argentine region. Phytoplankton samples were collected monthly(exceptionally fortnightly) and were measured environmental variables fromMarch 2004 to June 2008. Fifty-eight samples were analyzed for phytoplanktondensity and biomass. Five samples were used for toxicity testing; the latterwere obtained during the cyanobacteria blooms from 2005 to 2008. Phytoplanktoncounts were performed with an inverted microscope and the biomass was expressedas biovolume. Bioassays with mice and analysis by high-performance liquidchromatography (HPLC) were performed to evaluate the presence of cyanotoxins.Phytoplankton mainly consisted of Cryptophyta, Chlorophyta and Bacillariophyta.Microcystis aeruginosa was identified during the warmer months each year(November to March). Density varied between 189 and 25 027cells/mL (1-10colonies/mL) and biomass from 0.34 to 44mm3/L. Taking into account the numberof cells, the highest abundance occurred in April 2004 (25 027cells/mL),coinciding with the largest biovolume (44mm3/L). All mice subjected tointraperitoneal injections with samples obtained during bloom episodes showedpositive results for the presence of hepatotoxins. Three microcystins variants:LR, RR and [D-Leu1] Mcyst?LR, were detected by analysis with semi-preparativehigh-performance liquid chromatography with diode array detector system(HPLC-PDA). This is the first report of microcystins recorded during M.aeruginosa blooms in the Argentine stretch of the Paraná River at the beginning of the Middle Paraná (CorrientesHydrometer), approximately 220km downstream of the Yacyretá dam (High Paraná).