Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

Arctic sea-ice shrinking opens new biogeographical and ecological frontiers that relate essential microscopic primary producers, i.e. the diatom microalgae, to human economic and social activities. In the context of current global warming, future trend of Arctic Ocean primary production, the substance of marine food-webs and vital support to the Northerners marine resources, is poorly understood. It particularly depends on intrinsically related paradoxes: 1) While longer periods and larger areas of free waters will open new territories for humans, they will be colonized by new diatoms, migrating from the Atlantic and Pacific, or being transported in the ballasts of commercial vessels using the new Northern maritime routes, 2) While a mild increase in light availability is predicted to enhance pan-Arctic marine production, too much sustained or episodic light could reduce the productivity of diatoms together with modifying their ‘food quality’ properties. These interlaced forthcoming events will modify the face of Arctic Ocean primary production, making it essential to understand the ecophysiological light-response of diatoms (growth, productivity and acclimation) under current and future light conditions. Arctic Ocean primary production is closely related to the seasonal diatom photosynthetic productivity and species succession. It integrates the functional and ecological diversity of growth and life forms, cell size, depth-adaptation. Therefore there is a need to comprehend how the functional and ecological diversity of Arctic diatoms light-response explains the present and future trends of Arctic marine primary production: this is the objective of my Discovery program proposal. It articulates around 4 short-term objectives: O1) Comparison of the growth and life forms, O2 and O3) Influence of cell size and depth-adaptation, and O4) Confrontation with potential future temperate invaders. My Discovery program proposal is supported by i) the precise knowledge of the diversity, ecology and environment of Arctic diatoms; ii) the unique access to a collection of strains, and the ability to grow them in Arctic-simulated conditions; iii) the ability to investigate photophysiology at the species and community levels with lab experiments and field monitoring; iv) a multidisciplinary approach coupling genetics, biochemistry and (eco-)physiology. Each objectives is interactively served by Tasks defining the research projects of 9 students: 3 B.Sc., 3 M.Sc. and 3 Ph.D. students. Furthermore, the collaborative foundation of my Discovery program proposal built on internationally acknowledged scientists from Canada and France will greatly contribute to the training of the next generation of Arctic and algae experts to support the better predictive sustainability of Arctic marine ecosystems in the context of accelerating global warming.