title: Disruption of the hatching dynamics of zooplankton egg banks due to glyphosate application.
abstract: Hatching rhythms of eggs banks are important processes because they favor species co-existence and promote resilience of ecosystems after natural disturbances. Anthropogenic stressors can disrupt such natural hatching dynamics. This work examines the effects of concentrations ranging from 1 to 8 mg l-1of a commercial glyphosate-based formulation (Sulfosato Touchdown®) on the hatching dynamics of zooplankton dormant stages, present in the sediment of a natural lake. Sediment samples were collected from the surface sediment (<10 cm deep) of an isolated shallow lake free from pesticide pollution. An ex situ emergence assessment method was carried out and four treatments plus one control (without pesticide) were performed with three replicate each. Zooplankton hatching from the resting stages was monitored during 30 days. In total, 30 zooplankton taxa were recognized. The species diversity decreased significantly at concentration above 2.7 mg l-1glyphosate. The proportion of cladocerans within hatchling organisms decreased, while that of rotifers Bdelloidea increased in all treatments with glyphosate. Time of the first hatching (TFH), time of maximum hatching (TMH) and the frequency of hatchings (FH) of most zooplankton species were also altered. In conclusion, the application of a glyphosate-based pesticide selectively affected the hatching dynamic of zooplankton egg banks, which suggest that these resting structures are highly sensitive to the toxicity of the pesticide.
authors.affiliation: Instituto Nacional de Limnología (CONICET-UNL), Ciudad Universitaria, 3000 Santa Fe, Argentina; Escuela Superior de Sanidad (FBCB-UNL), Ciudad Universitaria, 3000 Santa Fe, Argentina. Electronic address: fgutierrez@inali.unl.edu.ar.
authors.forename: María Florencia
authors.initials: MF
authors.lastname: Gutierrez
authors.affiliation: Instituto Nacional de Limnología (CONICET-UNL), Ciudad Universitaria, 3000 Santa Fe, Argentina; Universidad Autónoma de Entre Ríos, Facultad de Ciencia y Tecnología, 3100 Entre Ríos, Argentina. Electronic address: yabattauz@yahoo.com.ar.
authors.forename: Yamila
authors.initials: Y
authors.lastname: Battauz
authors.affiliation: Universidad Autónoma de Entre Ríos, Facultad de Ciencia y Tecnología, 3100 Entre Ríos, Argentina.
authors.forename: Belén
authors.initials: B
authors.lastname: Caisso
mesh_terms: D000818:Animals; D033361:Cladocera / Q000187:drug effects; D005998:Glycine / Q000031:analogs & derivatives* / Q000633:toxicity; D006540:Herbicides / Q000633:toxicity*; D060106:Lakes; D009943:Organophosphorus Compounds / Q000633:toxicity; D012403:Rotifera / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015048:Zooplankton / Q000187:drug effects*; D015053:Zygote / Q000187:drug effects*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D006540:Herbicides; D009943:Organophosphorus Compounds; D014874:Water Pollutants, Chemical; D000097797:Glyphosate; C404484:N-(phosphonomethyl)glycine trimethylsulfonium salt
keywords: Bdelloidea; Pesticides; Resilience; Resting eggs