Impact of interaction between Limnoperna fortunei and Roundup Max® on freshwater phytoplankton: An in situ approach in Salto Grande reservoir (Argentina)

The joint impact of the glyphosate-based commercial formulation Roundup Max® and the invasive mussel Limnoperna fortunei on phytoplankton and water quality was assessed in Salto Grande reservoir, a scenario were both stressors coexist. We performed an in situ mesocosm approach, through a 7-day exper...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Gattás, F., De Stefano, L.G., Vinocur, A., Bordet, F., Espinosa, M.S., Pizarro, H., Cataldo, D.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00456535_v209_n_p748_Gattas
Aporte de:
Descripción
Sumario:The joint impact of the glyphosate-based commercial formulation Roundup Max® and the invasive mussel Limnoperna fortunei on phytoplankton and water quality was assessed in Salto Grande reservoir, a scenario were both stressors coexist. We performed an in situ mesocosm approach, through a 7-day experiment using 400-L enclosures. The following treatments were applied by triplicate: addition of 250 mussels (M); addition of 5 mg L−1 of active ingredient (a.i.) in Roundup Max® (R); addition of 250 mussels and 5 mg L−1 of a.i. in Roundup Max® (MR), and controls, without any addition (C). R showed higher total phosphorus (TP) and ammonium nitrogen (N–NH4 +) concentrations due to the herbicide input, and a significant increase in algal abundance, biovolume and chlorophyll a levels (Chl-a). In M mussels grazed on phytoplankton, which resulted in subsequent phosphates (SRP) release. A decrease in species diversity was observed in R and M with respect to C. In MR, there were higher TP and N–NH4 + concentrations, a decrease in biovolume, an antagonistic effect on Chl-a and a synergistic effect on phytoplankton abundance. Species diversity and evenness showed a significant decrease due to the explosive growth of a small and opportunistic Chlorophyta, Spermatozopsis exsultans. The dominance of this species may be due to negative selectivity for S. exsultans and/or release of potential competitors by L. fortunei, and to the input of nutrients by Roundup Max® and/or removal of competitors by its toxicity. © 2018 Elsevier Ltd