Stock identification of chinook salmon (Oncorhynchus tshawytscha) in the North Pacific Ocean and Bering Sea by parasite

• Main Authors: S. Urawa, K. Nagasawa, L. Margolist, A. Moles
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1998
• Subjects: Bering Sea; Island B; Pacific; Kamchatka
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.371.8801; http://www.npafc.org/new/publications/Bulletin/Bulletin No. 1/page 199-204(Urawa).PDF

The continental origins of chinook salmon (Oncorhynchus tshawytscha) in the North Pacific Ocean and Bering Sea were estimated by using two freshwater parasites (Myxobolus arcticus and M. kisutchl) as biological tags. The parasite survey of adult chinook salmon from major spawning rivers in North America and Kamchatka indicated that M. arcticus was commonly found in Asian chinook stocks (prevalence=57-94%), while rarely among most North American stocks except for those from Vancouver Island, B. C. The unweighted overall sample prevalence of M. arcticus was 67.7 % and 2.3% in Asian and North American stocks, respectively. Myxobolus kisutchi was found only in chinook salmon from the Columbia River (prevalence=8-11 % and 43-65 % in fall and spring adult stocks, respectively) and its vicinities. The prevalence of M. arcticus in high-seas samples of chinook salmon showed a distinct longitudinal cline in the North Pacific Ocean: the overall prevalence was 92 % west