Microcystin–LR, -RR, -YR and –LA in water samples and fishes from a shallow lake in Argentina

AMÉ, MARÍA VALERIA; GALANTI, LUCAS NICOLÁS; MENONE, MIRTA; GERPE, MARCELA; MORENO, VICTOR; WUNDERLIN, DANIEL ALBERTO

HARMFUL ALGAE

ELSEVIER SCIENCE BV

Año: 2010 vol. 9 p. 66 - 73

1568-9883

We evaluated the presence of four common microcystins (MC-LR, -RR, -YR and -LA) in water samples and tissues (liver and muscle) of Odontesthes bonariensis collected in Los Padres Lake (Argentina). MC were quantified by HPLC-ESI-MS/MS. The total content of MC in water samples (2.9 ± 5.8 ìg L-1) and in O. bonariensis muscle (3.9 ± 2.2 ìg g-1) never surpassed guidelines values recommended by WHO for either recreational use of water or fish consumption. However, we observed both spatial and temporal changes in MC profile, suggesting the need of an intensive monitoring program at such lake to ensure the health of people living in its surrounding. We observed a significant correlation between the content of MC (total and dissolved) and its concentration in liver, showing the probable uptake of dissolved MC by O. bonariensis. MC-RR was the dominant variant in water samples, followed by MC-LA and MC-LR. MC-YR was always present in water samples showing the lowest concentration. MC content in liver in O. bonariensis was ten-fold higher than the corresponding content in fish muscle. However, MC were present in muscle of O. bonariensis during both wet and dry season, while we did not detect MC in liver during the dry season. These results demonstrate that MC accumulation in liver and muscle of O. bonariensis occurred with different profiles. Moreover, different uptake, tissue distribution and excretion pathways may occur between diverse MC variants. For instance, during the dry season, an increment in the relative percentage of MC-LR in water samples was accompanied with an augment in the relative percentage of this toxin in muscle of O. bonariensis. Conversely, a rise in the relative percentage of MC-LA in water samples during the dry season did not impact on the distribution of this toxin in fish muscle. These results suggest the need of further studies on dynamics of different variants of MC to pursuit a complete evaluation of human health risk associated to MC occurrence.