PEREZ Gonzalo Luis
congresos y reuniones científicas
Roundup TM (Glyphosate formulation) effects on freshwater periphyton: experimental approach using mesocosms
PIZARRO, H; VERA, M. S; SYLVESTER, M; BUSTINGORRY, J; ESCARAY, R.;; FERRARO, M; PÉREZ, G. L.; RODRÍGUEZ, P. L.; MUGNI, H; BONETTO, C; ZAGARESE, H
St. John's, Newfoundland & Labrador
Congreso; ASLO Summer Meeting; 2008
Glyphosate formulation (Roundup®) effects on periphyton community were studied by means of six experimental mesocosms (25m2 × 1m): three were treated with 6 mg l-1 of Roundup® and 3 were considered control (without herbicide). Artificial substrates were used in each mesocosm for periphyton colonization and collected 8, 14, 20 and 34 days after addition. Dry weight, ash-free dry weigth, chlorophyll a, primary production as well taxonomic composition and density of live and dead algae were analised. All periphytic variables for treated mesocosms showed lower values during the entire experiment (p<0.05; MannWhitney test). Significant differences (p<0.05; Friedman test) were detected among sampling dates for variables at control mesocosms but not always for the treated ones. In mesocosms with Roundup® algal composition turned to the increase of cyanobacteria while density of dead algae was significantly higher (p<0.05, MannWhitney test). The observed changes in the structure and functionality of periphyton are consistent with a direct toxicological effect of glyphosate formulation. Given the importance of the periphyton community in shallow aquatic systems, glyphosate effects on periphyton are likely to spread through the whole aquatic food web.