Comparative toxicity of insecticides, fungicides and herbicides widely used in the Pampas (Argentina) on the ?Pejerrey? (Odontesthes bonariensis)

LóPEZ ACA, V.; GONZALEZ, P.V.; CARRIQUIRIBORDE, P.

Vancouver

Congreso; SETAC North America 35th Annual Meeting; 2014

Society of Environmental Toxicology and Chemistry

A marked agriculture intensification in the Pampas Argentina has been observed in the last ten years. Such intensification was accompanied of a shaped increased in the use of pesticide. In a recent SETAC-LA workshop the need of information for local species was remarked. In the present study the acute toxicity of 4 insecticides (endosulfan, chlorpyrifos, ë-cyhalothrine, imidacloprid), 2 fungicides (epoxiconazole, tebuconazole) and 2 herbicides (atrazine, glyphosate), together with the synergist piperonyl butoxide, all broadly used in the region were assessed on the regionally emblematic species ?Pejerrey? (Odontesthes bonariensis). Ninety-six hour standardized bioassay were run at least three times using 15-30 day old fish in La Plata dechlorinated tap water. Mortality was recorded and the 24, 48, 72, and 96h LC50 were estimated using the Probit analysis. The toxicity (in µg/L a.i.) as the 48h LC50 (confident interval) for the nine assessed pesticides in decreasing order was ë-cyhalothrine 0.09 (0.06-0.14), endosulfan 0.85 (0.47-3.80), chlorpyrifos 15.0 (5.21-179), epoxiconazole 1,170 (780-1,860), piperonyl butoxide 5,680 (3,310-9,740) and imidacloprid 166,000 (149,000-185,000). No values were obtained for tebuconazole and the two herbicides at 48h. Accordingly with the 96h LC50 the toxicity rank was ë-cyhalothrine 0.02 (0.010-0.023), endosulfan 0.29 (0.12-0.71), chlorpyrifos 1.73 (0.96-3.11), epoxiconazole 40 (5-150), piperonyl butoxide 740 (250-2,230), tebuconazole 1,600 (640-3,990), atrazine 7,070 (5,540-9,020), imidacloprid 64,840 (52,450-80,160) and glyphosate 440,000 (25,600-876,700). This information will be useful as input for ecotoxicological risk assessment of pesticides in the region as well as guide for conducting further toxicological studies on pesticides with this emblematic species.