Yukon River Chinook Salmon Monitoring for Ichthyophonus Prevalence and Intensity ...

• Main Authors: Withers, Jonah, Walter, Scott
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: U.S. Fish and Wildlife Service 2024
• Subjects: Chinook salmon, Yukon River, Ichthyophonus; Yukon river; Alaska; Yukon
• Online Access: https://dx.doi.org/10.7944/p92u48s6; https://ecos.fws.gov/ServCat/Reference/Profile/161500

Salmon populations in the Yukon River are managed through fishing harvest regulations determined by estimates of how many individuals enter the river and are expected to reach their spawning grounds. The number of Canadian-origin Chinook salmon passing are estimated at a lower-river assessment site at Pilot Station (river mile [RM] 123) and at an upper-river site at Eagle (RM 1210); both sites are by the Alaska Department of Fish and Game (ADF&G). Counts should be comparable between sites given that this salmon stock must pass both locations during migration to spawning grounds further upriver in Canada. However, in recent years considerably fewer individuals passed the up-river site compared to the lower-river site. If fish mortality between the lower- and upper-river sites is the source for discrepancies in counts, it is important to identify the source of mortality and the degree of impact to better quantify numbers of migrating salmon. One potential source of mortality is Ichthyophonus, a fish ...