The Bureau environnement et terre d’Odanak and the Bureau environnement Wôlinak, in collaboration with the MFFP, have developed a project aimed at limiting the number of double-crested cormorants resting on the navigation aid structures of Lake Saint-Pierre during their fall migration.
This project, funded by the Ministère de la Défense Nationale, is part of the project to mitigate the public safety risk associated with unexploded explosive ordnance (UXO) in Lake Saint-Pierre, and aims to offset the fish mortality caused by this work by reducing the predation pressure caused by cormorants.
Indeed, in recent years, cormorants have become increasingly numerous in the region, and their numbers increase considerably between August and October, the period when they use the river to travel to their wintering grounds. Lac Saint-Pierre has 11 navigation aids to keep the ice out of the shipping channel, and these structures provide a perfect resting place for the birds to regain their strength. During this period, cormorants actively feed in the aquatic grass beds of Lac Saint-Pierre, where they feed on all kinds of fish species, including yellow perch.
More specifically, this project involves covering certain structures with heavy netting to prevent cormorants from landing on them. By reducing access to these resting stations, we believe that the cormorants’ migration patterns will be altered, that there could be a reduction in predation pressure on the fish and therefore a potential reduction in impact on the fish community.
Preliminary results demonstrate that the developments work to reduce accessibility to the blocks. However, more research will be needed to know if this directly translates into a reduction in predation on fish resources. For these reasons, our teams carry out various monitoring in parallel in order to better measure the impact that the developments have on the use of the cormorants’ resting and feeding habitat, both on a local and regional scale. We therefore use different inventory techniques, such as aerial counting using a drone and/or seaplane.
Grand Council of the Waban-Aki Nation, 2022. Fish mortality compensation project as part of the public safety risk mitigation project linked to unexploded explosive ordnance (UXO) in Lake Saint-Pierre of the Ministry of National Defense – Monitoring of the double-crested cormorant population of Lake Saint-Pierre and compensatory measures, summer and fall 2021. Report prepared by Samuel Dufour-Pelletier and Vanessa Fortin-Castonguay for Construction and Defense Canada. 43 pages and annexes.
