Cumulative impacts of regulating freshwater flows on the Gulf of Saint Lawrence and Scotian Shelf marine ecosystems


The difference in monthly average salinities between simulations with all rivers harnessed and simulations with all rivers flowing with natural conditions from 2006 to 2010 (blue color represents fresher conditions.)

Regulating the flow of rivers using hydroelectric dams has a profound effect on the annual cycle of river runoff, shifting the maximum runoff from spring to winter, and the minimum runoff from winter to summer. River runoff is one of the main drivers of circulation in the Gulf of St. Lawrence and its influence can be felt as far as the Scotian Shelf. Most of Quebec's large rivers are dammed and more soon will be, causing changes in runoff that lead to changes in circulation, sea ice formation and nutrient availability, which will in turn affect phytoplankton production, krill production and distribution, and potentially the distribution of some marine mammals. This project will use a modelling system to study and simulate the impacts of the modified runoff cycle caused by existing and future hydroelectric dams.

Program Name

Strategic Program for Ecosystem-based Research and Advice (SPERA)


Atlantic: Gulf of Maine, Scotian Shelf

Principal Investigator(s)

Diane Lavoie

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