Marion Cheron

Sub-lethal effects of environmental contaminants on the development of the spiny toad (Bufo spinosus): an experimental approach

Despite the general awareness of the risks associated with plant protection products, pesticides are still widely used in modern agriculture. However, while the hazards to non-target species are well demonstrated, these studies focus mainly on relatively high lethal doses. However, the concentrations of plant protection products found in the environment are very low and the impact of these so-called “sub-lethal” concentrations is difficult to quantify. Amphibians are particularly relevant for studying the effects of environmental contaminants. My thesis is based on two axes. Firstly, I seek to measure the impact of phytosanitary products (herbicides) at environmental concentrations on the development of a species still present in agricultural environments, the spiny toad (Bufo spinosus). This work aims to measure the impact of low doses of these products on embryonic (success, duration) and larval (duration, success and phenotype) development. Secondly, I want to understand the impact of habitat (agricultural versus forest) on the phenotype and physiology of adults. I therefore measured phenotypic (morphology), physiological (hormones, telomeres) and behavioural parameters on adult males from more or less agricultural habitats. These two approaches allow me to identify the phases of development that are sensitive to environmental contamination and to understand whether the effects measured in the laboratory are also detected in wild populations.

PhD student – ECOPHY team – PhD Director: François Brischoux
Doctoral School of La Rochelle Funding: Loire-Brittany Water Agency, New-Aquitaine Region, National Agency for Food, Environmental and Occupational Health Safety
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