Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 927
Title: Factors Influencing The Relavtive Fitness Of Hatchery And Wild Spring Chinook Salmon In The Wenatchee River, Washington
Author: K. S. Williamson, A. R. Murdoch, T. N. Pearsons, E. J. Ward, Michael J. Ford
Publication Year: 2010
Journal: Canadian Journal of Fisheries and Aquatic Sciences
Volume: 67
Pages: 1840-1851
DOI: 10.1139/F10-099
Abstract: Understanding the relative fitness of naturally spawning hatchery fish compared with wild fish has become an important issue in the management and conservation of salmonids. We used a DNA-based parentage analysis to measure the relative reproductive success of hatchery- and natural-origin spring Chinook salmon (Oncorhynchus tshawytscha) in the natural environment. Size and age had a large influence on male fitness, with larger and older males producing more offspring than smaller or younger individuals. Size had a significant effect on female fitness, but the effect was smaller than on male fitness. For both sexes, run time had a smaller but still significant effect on fitness, with earlier returning fish favored. Spawning location within the river had a significant effect on fitness for both sexes. Hatchery-origin fish produced about half the juvenile progeny per parent when spawning naturally than did natural-origin fish. Hatchery fish tended to be younger and return to lower areas of the watershed than wild fish, which explained some of their lower fitness.
URL1: The next link will exit from NWFSC web site Link to abstract
Official Citation: Williamson KS, Murdoch AR, Pearsons TN, Ward EJ, Ford MJ. 2010. Factors influencing the relative fitness of hatchery and wild spring Chinook salmon (Oncorhynchus tshawytscha) i the Wenatchee River, Washington, USA