Effect of environmental parameters on toxicity of emerging contaminants.

For several years, we have been developing projects aimed at understanding how pollutants can affect fish development and what are the long-term consequences on behavioural skills, fish physiology and populations using model fish.

The internship agreement will be established with INRAE and the internship will be carried out at the Ifremer Station in Palavas (France - 34) within the UMR MARBEC.

Background and general objectives of the internship

In a changing marine environment, variations in the physicochemical parameters of water can significantly disrupt the behaviour and physiology of marine organisms. These changes can also affect the toxicity of chemicals by changing their availability in the environment and the organisms' ability to metabolize them once assimilated. Within the CONTRAST-CLIMTOX project, this internship will aim to assess the effect environmental parameters in the toxicity of chemicals of emerging concern, with its main focus on salinity. This will be addressed using the model species marine medaka (Oryzias melastigma). This species tolerates a broad range of salinity, among other parameters, being able to be reared in both fresh and saltwater conditions. This will allow us to assess the actual effects of salinity in chemical toxicity using the same species and therefor avoiding most of the species-specific differences that could mask the effect of salinity.

Description of the internship

The toxicity of different contaminants of emerging concern will be evaluated at different salinities using short term exposures in embryos and larvae of marine medaka. Eggs will be obtained from broodstock that have already been adapted in fresh or marine water. Toxicity will be assessed according to lethality, morphological defects, behaviour, and molecular responses. This will provide information on the effect of salinity in the toxicity of the chemicals tested and contribute to develop a standardized methodology for the assessment of chemical toxicity in a model marine species.

The candidate will have completed training in physiology and/or ecotoxicology. He/she will have a taste for experimental work and the use of animal models.