New evidences of Roundup (glyphosate formulation) impact on the periphyton community and the water quality of freshwater ecosystems.
Argentina is the second largest world producer of soybeans (after the USA) and along with the increase in planted surface and production in the country, glyphosate consumption has grown in the same way. We investigated the effects of Roundup (glyphosate formulation) on the periphyton colonization. The experiment was carried out over 42 days in ten outdoor mesocosms of different typology: "clear" waters with aquatic macrophytes and/or metaphyton and "turbid" waters with great occurrence of phytoplankton or suspended inorganic matter. The herbicide was added at 8 mg L(-1) of the active ingredient (glyphosate) in five mesocosms while five were left as controls (without Roundup addition). The estimate of the dissipation rate (k) of glyphosate showed a half-life value of 4.2 days. Total phosphorus significantly increased in treated mesocosms due to Roundup degradation what favored eutrophication process. Roundup produced a clear delay in periphytic colonization in treated mesocosms and values of the periphytic mass variables (dry weight, ash-free dry weight and chlorophyll a) were always higher in control mesocosms. Despite the mortality of algae, mainly diatoms, cyanobacteria was favored in treated mesocosms. It was observed that glyphosate produced a long term shift in the typology of mesocosms, "clear" turning to "turbid", which is consistent with the regional trend in shallow lakes in the Pampa plain of Argentina. Based on our findings it is clear that agricultural practices that involve the use of herbicides such as Roundup affect non-target organisms and the water quality, modifying the structure and functionality of freshwater ecosystems.
Vera
María S
MS
Laboratorio de Limnología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pab. II, C1428EHA, Buenos Aires, Argentina.
Lagomarsino
Leonardo
L
Sylvester
Matías
M
Pérez
Gonzalo L
GL
Rodríguez
Patricia
P
Mugni
Hernán
H
Sinistro
Rodrigo
R
Ferraro
Marcela
M
Bonetto
Carlos
C
Zagarese
Horacio
H
Pizarro
Haydée
H
D001118:Argentina; D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D000458:Cyanobacteria / Q000187:drug effects / Q000254:growth & development; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D056890:Eukaryota / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D005068:Eutrophication; D005618:Fresh Water / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity; D006540:Herbicides / Q000378:metabolism / Q000633:toxicity*; D010758:Phosphorus / Q000378:metabolism; D018570:Risk Assessment; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D000097797:Glyphosate
D002734:Chlorophyll; D000077194:Chlorophyll A; D005998:Glycine; D006540:Herbicides; D010758:Phosphorus; D014874:Water Pollutants, Chemical; D000097797:Glyphosate