Monday, September 13, 2010
Hall B (Convention Center)
Extensive natural reproduction of Chinook salmon (Oncorhynchus tshawytcha) in the Salmon River, New York has raised many questions about the management of this species. This study examines the contribution of wild-origin Chinook salmon in the Salmon River during the 2005 spawning run. Using a recently developed method for determining the origin (hatchery or wild) of Lake Ontario Chinook salmon we estimated that approximately 32% (~20,000 individuals) of returning fish were of wild-origin and that there was a greater proportion of wild fish in younger age groups than in older groups (age 1 = 48.6%, age 2 = 47.2%, age 3 = 21.1%). We also observed spatial differences in the distribution of wild- and hatchery-derived fish, with a higher proportion of wild-origin Chinook salmon in the lower section of the river (47.5%) than in the upper sections (28.2%). The lowest proportion of wild fish was found in the Salmon River hatchery (12.4%). This study reinforces the conclusion that naturally produced Chinook salmon are an important component to the Salmon River fishery.