Introduced Salmonids: Where Are They Going in Quebec Watersheds of the Saint-Laurent River?

Salmonid fish (Salmonidae) are among the most important sport and commercial species in North America. Numerous attempts to extend their range have been made over the past 100 years. In Canada, Québec was among the first provinces to be involved in such attempts. Rainbow trout (Salmo gairdneri), brown trout (S. trutta), cutthroat trout (S. clarki), kokanee (Oncorhyncus nerka), Arctic grayling (Thymallus arcticus) and huchen (Hucho hucho) were experimentally introduced in various lakes and rivers of the southern part of the province. Some of these species, along with pink (O. gorbuscha), chinook (O. kisutch), and coho salmon (O. tshawytscha), were also stocked intensively in neighbouring states and provinces. Rainbow, brown, and cutthroat trout species are now established in southern Québec. Present data also indicate that rainbow and, to a lesser extent, brown trout gradually increased in numerous rivers flowing into the Gulf of Saint-Laurent, along the North Shore and the Gaspé Peninsula. Pink salmon were caught at three sites on the North Shore of the Gulf in 1967 and 1975. For the last 10 years, an increasing number of coho and chinook salmon have been caught near Montréal, Trois-Rivières, Québec, and as far downstream as Pointe-au-Pére. Chinook and probably coho salmon spawn in the Saint-Laurent River near Montréal. All these plantings were done without previously evaluating the impact on existing fish communities at the location of introduction and in interconnected waters. Since risks exist (importation of diseases, competition, habitat alteration, hybridization) that vary greatly depending on the community involved and the species that is transplanted, we believe that it is imperative to implement a formal international code of practice for regulating the introduction of aquatic species and we firmly support the present initiative of the American Fisheries Society on this problem.