Marie Curie fellowship
This project aims at improving current knowledge and approaches for the ecological risk assessment of pesticides, focusing on the study of the effects of pesticides on populations of aquatic snails (Lymnaea stagnalis). The main theoretical interests will be on understanding the physiological and toxicological determinants of the sublethal response to pesticides in exposed snails, and on assessing how the effects that are observed/predicted in individuals may propagate to the population level.
Studies will thus be based on the coupling of experimental and modelling approaches. From the applied perspective, the focus will be on improving existing mechanistic effect models for the prediction of effects on individuals (based on toxicity test data) and the extrapolation to population effects of pesticides in realistic conditions of pesticide use. Results will contribute to consolidate the basis of forthcoming toxicity test methods and models to evaluate population effects of chemicals.
Detailled description of the PhD Position: Marie Curie fellowship within the CREAM ITN
Obtaining more realistic risk forecasts of pesticides on populations of nontarget species requires to improve current knowledge, toxicity test methods and data analysis tools. Approaches based on the Dynamic Energy Budget theory seem promising in this context. Indeed, DEB theory provides a physiology-based conceptual framework where effects on survival, growth and reproduction can be simultaneously investigated. Moreover, predicted individual responses to toxicants can directly be used as input data for population effect models. Yet, some ecotoxicological issues remains to be tackled in the DEB framework e.g. how to assess effects of time-varying concentrations and low doses of toxicants, which generate complex response pattern? How to explain patterns of individual recovery after exposure ceases?
This PhD project thus aims at exploring how the DEB theory could be used as a basis to improve existing mechanistic models for the analysis of biological responses to toxicants, focusing on three key issues for refined risk assessment practices:how to deal with complex exposure profiles, how to deal with complex responses to toxicants that are active at low doses and how to account for recovery.
Studies will be based on the coupling of experimental and modelling approaches in the pond snail. Snail’s responses to pesticide exposure will be quantified through lab toxicity tests, focusing on the study of reproductive responses to low doses of toxicants. Observed exposure, effect and recovery patterns will be interpreted and modelled within the DEB framework. This may require adapting the physiological/ toxicological assumptions underlying the currently available models. Finally, effects modelled at the individual level will be extrapolated to the population level.
PhD objectives are to:
– identify from literature chemicals that generate reprotoxicity at low doses in non-target aquatic molluscs
– design and implement laboratory toxicity tests in order to investigate effects and recovery patterns of snails exposed to the selected chemicals
– gain experience with current DEB models on toxicity data, and modify them when necessary in order to ensure that they can adequately explain patterns of effects and recovery in exposed snails
– upscale from individual to population-level effects of toxicants based on existing population models.
Expected outputs are validated/documented test methods and comprehensive effect models. Results will contribute to consolidate the basis of forthcoming standardized toxicity test methods and models to evaluate population effects of pesticides.
Candidates should be interested in ecotoxicology and mathematics. Basic skills in ecological modelling and / or ecotoxicology are desired. Experiments will be implemented at the INRA and modelling will be performed in close collaboration with the VU Amsterdam, so that mobility and ability to cooperate in a research consortium is required.
Benefits
1. Candidate’s skills will be complemented by attendance of advanced training courses proposed by the CREAM initial training network, leading to an advanced level of initial training.
2. Integrating the CREAM research consortium will facilitate obtaining a position in academia and governmental institutions or industry after graduation.
3. The PhD thesis will be defended both in France and in The Netherlands, enabling the candidate to obtain a Double Doctorate graduation.
4. Terms of employment (e.g. vacation days, parental leave, etc.) will be in accordance with Marie-Curie rules of the European Commission and Host Institution’s (INRA) rules.
Further information
Please see the detailed description of this PhD project, named “DEB-2”, in the web page dedicated to the CREAM EU- project (Mechanistic Effect Models for Ecological Risk Assessment of Chemicals) at www.cream-itn.eu
The position is available on October 2010
Duration: 3 years
Required degree: Master degree in life sciences, preferably ecotoxicology
Required languages: English, very good level
To apply: Candidates should send their CV, motivation and recommandation letters to virginie.ducrot@rennes.inra.fr before the 15 of December 2010.
Please note that French citizens are not eligible
Website: http://www.inra.fr
Salary: 1900 euros/month
