Université du Québec en Outaouais
Candidat Ph.D.
superviseur(e): Katrine Turgeon
Début: 2022-09-01
Fin: 2025-09-01

Projet

Complexity, configuration, and stability of food web networks in aquatic ecosystems
Hydroelectricity has been recognized as a renewable energy source that has the potential to decarbonize our economy by reducing greenhouse gas (GHG) emissions, but without being detrimental to biodiversity, ecological functioning, or the food security of local communities. Recent work has revealed the occurrence of inverted trophic pyramids (ITPs) in Canadian boreal reservoirs. This trophic configuration is puzzling and should be unstable in theory. The main objective of this thesis is to examine the prevalence and stability of ITPs over space and time in reservoirs of different ages and to compare them to natural lakes. To accomplish this, we will use existing databases (e.g Hydro-Québec and MELCCFP) to study the prevalence and stability of ITPs in reservoirs using the predator-to-consumer mass ratio (PCMR) in fish. Additionally, empirical data from different reservoirs in Québec will be collected to complement the research and investigate the mechanisms that can lead to ITPs. To do so, I will use stable isotope analysis (SIA) and Bayesian mixing models with three-isotope inference. This approach will enable me to examine both endogenous and exogenous factors that may contribute to the creation of ITPs. By combining analytical methods with empirical data, I aim to gain a comprehensive understanding of the ecological interactions and processes driving ITP in hydroelectric reservoirs.