Impact of chronic exposure of rainbow trout, Oncorhynchus mykiss, to low doses of glyphosate or glyphosate-based herbicides - Archive ouverte HAL Access content directly
Journal Articles Aquatic Toxicology Year : 2021

Impact of chronic exposure of rainbow trout, Oncorhynchus mykiss, to low doses of glyphosate or glyphosate-based herbicides

Abstract

Glyphosate is an herbicidal active substance (AS) entering in the composition of a large diversity of pesticide products (glyphosate-based herbicides; GBH) used in modern intensive agriculture. This compound has a favorable environmental safety profile but was suspected to induce deleterious effects in aquatic organisms, with a potential effect of some associated co-formulants. This study aimed to assess the impact of direct and chronic exposure to glyphosate on the health status of rainbow trout, Oncorhynchus mykiss. A total of 36 genitors were exposed daily for 10 months to a dose of glyphosate representative of environmental concentrations (around 1 μg L-1) using the AS alone or two GBHs formulations (i.e. Roundup Innovert® and Viaglif Jardin®) and findings were compared to an unexposed control group (n=12). The effects of chemical exposure on the reproductive capacities, hemato-immunologic functions, energetic metabolism, oxidative stress and specific biomarkers of exposure were analyzed over a period of 4 months covering spawning. A limited mortality between 15% and 30% specific to the spawning occurred under all conditions. No differences were observed in reproduction parameters i.e. mean weights, relative fertility and fecundity. Red blood cell count, hematocrit index, mean corpuscular volume and white blood cell counts were similar for all the sampling dates. Significant changes were observed two months before spawning with a 70% decrease of the proportion of macrophages in trout exposed to Viaglif only and a reduction of 35% of the phagocytic activity in fish exposed to the two GBHs. Trends towards lower levels of expression of tumor necrosis factor-α (between 38% and 66%) were detected one month after the spawning for all contaminated conditions but without being statistically significant. Biomarkers of exposure, i.e. acetylcholine esterase and carbonic anhydrase activities, were not impacted and none of the chemical contaminants disturbed the oxidative stress or metabolism parameters measured. These results suggest that a 10 months exposure of rainbow trout to a concentration of 1 μg L-1 of glyphosate administered using the pure active substance or two GBHs did not significantly modify their global health including during the spawning period. The immunological disturbances observed will need to be further explored because they could have a major impact in response to infectious stress.
Fichier principal
Vignette du fichier
S0166445X20304379.pdf (514.01 Ko) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-03494065 , version 1 (15-12-2022)

Licence

Attribution - NonCommercial

Identifiers

Cite

Jessy Le Du-Carrée, Thierry Morin, Morgane Danion. Impact of chronic exposure of rainbow trout, Oncorhynchus mykiss, to low doses of glyphosate or glyphosate-based herbicides. Aquatic Toxicology, 2021, 230, pp.105687. ⟨10.1016/j.aquatox.2020.105687⟩. ⟨hal-03494065⟩
115 View
34 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More