Illustration by Fred Reibin

Hudson Bay on the World Stage

To dam a river is to dam the world

Tricia Stadnyk
University of Calgary, Chair: NSERC Tier 2 Canada Research Chair in Hydrological Modelling

A recent meeting with a movie producer made me reflect on one simple question: "Why should the world care about Hudson Bay?" As I contemplate my answer a memory comes to mind. I have studied water for what seems like my whole life, so I remember feeling like my whole life had led me there, to that point.

It is 2010. I am standing along the banks of the mighty Nelson River upstream of where it thunders into Hudson Bay. The current is so strong it seems to generate its own wind, carrying the smell of mud and fish and rock in its breathe. This is unlike anything I have experienced or expected, something I have only seen in two dimensions on a paper map. I am perched on a rocky outcrop about to dip an isotope sample bottle into the raging torrent of a waterfall that will soon be drowned by a new hydroelectric development along this wild and fierce river. In awe of the power this river, I stand there and it is as if the world paused for a moment. I watch the gulls feasting on the fish jumping at the falls, and listen to the rushing of water and the bird calls, knowing this place will soon cease to exist.

Change along this mighty river is a story that originates in the Rocky Mountains of Canada and travels over thousands of kilometers. It is a tragic combination of how we've altered and fragmented its course to leverage the river's power to generate electricity powering homes in the south, or the - also human altered- extreme changes in climate this northern region is undergoing. And yet, it also represents an opportunity for greener energy transitions for Canada to fuel our expanding population.

Now, nearly eight years later I feel prepared to answer this movie producer's question. I describe to them the value that this massive drainage system of rivers and Hudson Bay holds for the rest of the world.

"Freshwater from one third of Canada's landmass drains into the Bay, with the Nelson River delivering the most. This unique marine system connects freshwater and Arctic marine waters It is truly the heart and lungs of the world, regulating global climate by discharging cold, saline waters into the Labrador Sea through Hudson Strait that sink deep below the warmer, less salty waters originating from the Gulf of Mexico.

This mixing of different waters drives a "conveyor belt" of water around the globe. Damming the freshwater that flows into Hudson Bay changes the speed and consistency of ocean currents that regulate global climate."

I can see the movie producer's attention beginning to wander as he glances at his phone.

"So, why should the world care? Well, the entire Northern Hemisphere depends on it." They look back up in interest. "This conveyor system winds its way around the globe, regulating our weather. It is a highly delicate and easily disrupted dance. Once disrupted, global weather becomes highly chaotic and prone to sudden changes in pressure. This means higher winds, hurricanes, more extreme flood and drought, and cold spells in parts of Europe. If Hudson Bay is the heart and lungs of the world, then the rivers feeding the Bay - like the Nelson River - are its arteries delivering the lifeblood of the system." The producer stops me there.

The movie? Still not produced, perhaps because the cautionary tale I want the world to hear is that development on rivers may have local benefits, but there are far reaching implications that raise important philosophical and moral issues that have yet to be discussed or debated. Is any one development worth changing the world for? If we knew the consequences, would be make the same choices on the land and to the rivers? If the answer is perhaps not, then you now know why the world needs large-scale modelling and prediction.

Find out more:

Mohamed Ismaiel Ahmed, Tricia Stadnyk, Alain Pietroniro, Hervé Awoye, Ajay Bajracharya, Juliane Mai, Bryan A Tolson, Hongren Shen, James R Craig, Mark Gervais, Kevin Sagan, Shane Wruth, Kristina Koenig, Rajtantra Lilhare, Stephen J Déry, Scott Pokorny, Hank Venema, Ameer Muhammad, Mahkameh Taheri. 2023. Learning from hydrological models' challenges: A case study from the Nelson basin model intercomparison project. Journal of Hydrology 623, DOI: 10.1016/j.jhydrol.2023.129820

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