ASSOCIATED RESEARCH – Saguenay Fjord–St. Lawrence Estuary connectivity of groundfish populations exploited by winter recreational fishing

Recreational winter fishing, also known as ice fishing, is a popular activity along the Saguenay Fjord, generating significant economic spinoffs for the region. This ice fishing activity is unique in Quebec for its scope and the diversity of the species caught. Atlantic redfish (Sebastes mentella), Atlantic cod (Gadus morhua) and Greenland halibut (Reinhardtius hippoglossoides) are among the marine species most exploited by this activity.

However, previous studies suggest that the recruitment of these species in the fjord depends on the migration of juveniles from the Gulf and Estuary of St. Lawrence. Their recruitment would therefore be dependent on conditions outside the Saguenay Fjord, which could make these species highly vulnerable to exploitation.

This project aims to determine the connectivity of these three groundfish species between the Saguenay Fjord and the St. Lawrence Estuary. This connectivity will be established using the elemental footprint of otoliths, calcareous concretions in the inner ear of fish that serve as natural recorders of environmental conditions. Analysis of the chemical composition of otoliths will reveal the life stage at which these fish enter the fjord and whether they become residents of the fjord or continue to move between the Saguenay and St. Lawrence rivers. The study of trace elements in the otoliths of these species should provide a better understanding of their recruitment in the Saguenay Fjord and thus promote a more sustainable exploitation.

This project is co-directed by Dominique Robert (UQAR-ISMER).