title: Direct and indirect effects of the glyphosate formulation Glifosato Atanor® on freshwater microbial communities.
abstract: Glyphosate-based formulations are among the most widely used herbicides in the world. The effect of the formulation Glifosato Atanor(®) on freshwater microbial communities (phytoplankton, bacterioplankton, periphyton and zooplankton) was assessed through a manipulative experiment using six small outdoor microcosms of small volume. Three of the microcosms were added with 3.5 mg l(-1) of glyphosate whereas the other three were left as controls without the herbicide. The treated microcosms showed a significant increase in total phosphorus, not fully explained by the glyphosate present in the Glifosato Atanor(®). Therefore, part of the phosphorus should have come from the surfactants of the formulation. The results showed significant direct and indirect effects of Glifosato Atanor(®) on the microbial communities. A single application of the herbicide caused a fast increase both in the abundance of bacterioplankton and planktonic picocyanobacteria and in chlorophyll a concentration in the water column. Although metabolic alterations related to oxidative stress were induced in the periphyton community, the herbicide favored its development, with a large contribution of filamentous algae typical of nutrient-rich systems, with shallow and calm waters. An indirect effect of the herbicide on the zooplankton was observed due to the increase in the abundance of the rotifer Lecane spp. as a consequence of the improved food availability given by picocyanobacteria and bacteria. The formulation affected directly a fraction of copepods as a target. It was concluded that the Glifosato Atanor(®) accelerates the deterioration of the water quality, especially when considering small-volume water systems.
authors.affiliation: Laboratorio de Limnología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA, Ciudad de Buenos Aires, Argentina.
authors.forename: María Solange
authors.initials: MS
authors.lastname: Vera
authors.forename: Eugenia
authors.initials: E
authors.lastname: Di Fiori
authors.forename: Leonardo
authors.initials: L
authors.lastname: Lagomarsino
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Sinistro
authors.forename: Roberto
authors.initials: R
authors.lastname: Escaray
authors.forename: María Mercedes
authors.initials: MM
authors.lastname: Iummato
authors.forename: Angela
authors.initials: A
authors.lastname: Juárez
authors.forename: María del Carmen
authors.initials: Mdel C
authors.lastname: Ríos de Molina
authors.forename: Guillermo
authors.initials: G
authors.lastname: Tell
authors.forename: Haydée
authors.initials: H
authors.lastname: Pizarro
mesh_terms: D000818:Animals; D017753:Ecosystem; D005618:Fresh Water / Q000737:chemistry / Q000469:parasitology; D005998:Glycine / Q000031:analogs & derivatives*; D006540:Herbicides; D059013:Microbial Consortia / Q000187:drug effects*; D010839:Phytoplankton / Q000187:drug effects*; D018675:Toxicity Tests; D060753:Water Quality; D015048:Zooplankton / Q000187:drug effects*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D006540:Herbicides; D000097797:Glyphosate