Evaluación Ecotoxicológica de Aguas Contaminadas con Glifosato a partir de los Bioindicadores Daphnia magna y Artemia salina

Abstract

Glyphosate has been used since 1974. In Ecuador, 38 commercial brands are registered. Although the direct effect occurs at the vegetal level, the new formulations and metabolites generated during its degradation are possible contaminants of aquatic ecosystems. Therefore, the present investigation contemplates an ecotoxicological study for the commercial herbicide GLIFOPAC (480 g.L-1 of active ingredient or a.i.) on the bioindicators Daphnia magna and Artemia salina. The methodology was based on ecotoxicological tests on D. magna (LC50-48 h and reproduction) and A. salina (LC50 - 48h). The toxicity ratio of fresh and marine water was determined by gas chromatography. The results established that the LC50 in D. magna and A. salina correspond to 27.4 and 70.4 mg a.i.L-1 respectively. The chronic toxicity in D. magna, established reproductive affectations at concentrations of NOEC and LOEC of 0.8 and 3.6 mg a.i.L-1 respectively. The chromatographic analysis determined the presence of 45 substances, among which are aliphatic chains with esters and ethers groups, glucofuranosa, glucopyranoside and galactopyranose cycles. In such a way that in this work the relation between the possible formation of different metabolites depending on each medium (saline or sweet) and the toxicity of aquatic organisms was established.