We are looking for a talented post-doc researcher with an interest in climate change ecology and modelling to join our dynamic lab working on continental aquatic ecosystems responses to global changes.
Context and scientific background
Diadromous fishes are migratory and cross-border resources: they move between fresh and marine waters (McDowall, 1988) and their populations share individuals between river basins, crossing administrative boundaries (e.g. states, countries). Diadromous fishes as for the rest of freshwater biodiversity are threatened by various human activities and climate change (Dias et al., 2017; Harrison et al., 2018). A generalized decline has been noticed for many diadromous fish species (Limburg and Waldman, 2009) with, in some cases, a climate-induced shift in the species ranges (e.g. the European smelt Osmerus eperlanus; Pronier and Rochard, 1998). The situation is obviously changing, causing new socio-economic and ecological interactions among territories to appear. Consequently, a transnational approach is required in Europe and elsewhere to account for and facilitate these spatial changes in fish populations through better-adapted management plans, and ease the adaptation of territories in the face of climate change (Pinsky et al., 2018). As a consequence, DiadES, a recently-funded European project (Interreg Atlantic Area; https://www.atlanticarea.eu/), will bring together ecologists, economists and key stakeholders from the five European member states bordering the Atlantic Ocean, i.e. France, Portugal, Spain, U.K. and Ireland, to start a joint valuation of ecosystem services associated to diadromous fishes and their potential evolution under climate change (Holmlund and Hammer, 1999; MEA, 2005; Limburg, 2009).
A critical part of DiadES work plan will be on assessing the trajectories in diadromous fish distributions under climate change conditions along the European Atlantic coasts. A previous modelling exercise led to the conclusions that three main responses were expected from diadromous fishes by the end of the century with a potential contraction, expansion or stability of their favorable habitats in this globally changing environment (Lassalle et al., 2008; Lassalle and Rochard, 2009). These conclusions relying on a correlative approach which linked environmental variables to distributional data did not take into account population dynamics processes and as such prevented the interpretation of results in terms of population viability and species distributions. Since then, a mechanistic species distribution model (SDMs) named G3RD was built for anadromous species reproducing in rivers and growing at sea (Rougier et al., 2014, 2015). Mechanistic SDMs are powerful and meaningful tools reproducing an entire species life cycle and the vital links that exist with the environment. But, among other things, the number of parameters to be filled usually prevented their use on broad lists of valuable species and reduced their impacts on the scientific community (Evans et al., 2015). For example, GR3D was only used for shads. Consequently, a new generation of models at the interface between correlative and mechanistic SDMs was needed. In hybrid SDMs, a habitat favorability model is coupled to a simple population dynamics module with explicit dispersal and mortality processes (Holloway et al., 2016; Singer et al., 2018). In parallel with these methodological developments, a great piece of work was done on providing guidelines for the correct interpretation of SDM outputs (Guillera-Arroita et al., 2015; Rougier et al., 2015). Correctly interpreting these results appeared increasingly important in achieving efficient management measures as climate change is changing the references and targets for both species and habitat restoration.
Main objectives of the position
Hybrid species distribution models will be ideally built for all the species under-scope in the DiadES project, i.e. the two species of shads (Alosa alosa and A. fallax) and lampreys (Petromyzon marinus and Lampetra fluviatilis), Atlantic salmon (Salmo salar), sea trout (Salmo trutta), European sturgeon (Acipenser sturio), European eel (Anguilla anguilla), European smelt and thin-lipped mullet (Liza ramada). The population dynamics module should include biological data gathered during the project lifetime. This integration will require discussions with field ecologists from various organizations and the translation of their results into proper model parameters. A habitat suitability module already exists for each species and should be up-dated by testing the relevance of new environmental variables available at large scale and including additional distribution data especially those coming from the marine domain. Also, the Intergovernmental Panel for Climate Change (IPCC) produced new scenarios of climate changes called Representative Concentration Pathways (RCPs) and thus new simulations of future climate conditions on Earth were published (https://www.ipcc.ch/). These scenarios became the norm in climate change ecology studies and should be use in the present work. These data need to be extracted from relevant databases for simulating future species distributions.
Current and futures species distributions should be then mapped using GIS softwares after discussing the best way to represent things to avoid misunderstandings and to be useful to a broad array of people, e.g. conservationists, decision makers, NGOs members, scientists of different research fields. One paper should be written presenting hybrid SDMs for diadromous fishes with simulations of future species distributions under climate change.
To a lesser extent, the post-doctoral fellow could also contribute to the translation of species distribution evolution into ecosystem services changes and consequences for human communities. This vital step in DiadES requires both theoretical and methodological developments and intense exchanges among project partners. The candidate will be involved in the resulting publication and depending on his/her implication could lead the writing of this collective work.
The suitable candidate must hold a PhD in quantitative ecology or in related fields. He or she should have a good level in advanced statistics and solid knowledge of ecological modelling using the R programme. An experience with species distribution models or population dynamics models will be appreciated. The applicant should be proficient in English at a level which allows contributions to plenary and workshop discussions and preparation of reports and scientific papers. The successful candidate should be autonomous in his/her work and have a dynamic outgoing personality for regular exchanges with DiadES project members and EABX colleagues. The applicant will work in close collaboration with project coordinators and will as such be involved in the project implementation and will gain experience on this point.
Host organization and supervision
Irstea is a French research organization in science and technology for environment and agriculture (https://www.irstea.fr/en). Research carried out by the Aquatic Ecosystems and Global Changes (EABX) unit aims to provide knowledge, build methods and improve tools to define and understand the status and dynamics of continental aquatic ecosystems (i.e. estuaries, lakes, rivers) by evaluating the response of these ecosystems and their key species (particularly diadromous fishes and aquatic plants) to a range of human-induced pressures (e.g. fishing, fragmentation, pollution, climate change) (https://www.irstea.fr/en/eabx). The post-doctoral fellow will be under the co-supervision of Géraldine Lassalle and Patrick Lambert, coordinators of the DiadES project. Guillem Chust from AZTI (Spain) will help in model discussion and development.
To apply for this 18-month position, please send a resume and cover letter to Géraldine Lassalle ([email protected]) and Patrick Lambert ([email protected]) before the 15th of March 2019. The preferred start date is the 1st of June 2019. The net monthly salary will be around 2000 euros.
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