To understand the relative impact of regulation and climate change to the HBC, the freshwater team investigated the role of freshwater timing and magnitude on contemporary and future projections of freshwater-marine coupling in Hudson Bay. The team did this by developing continental-scale modelling of the entire Hudson Bay watershed. They conducted uncertainty assessments on the model and projected net changes to runoff under climate, regulation, and naturalized conditions. Results from this team were integral to the ability of other teams to evaluate the impacts of climate change and hydroelectric regulation on the physical, biological, and biogeochemical processes in the bay.