Yukon (Pilot) River
The Yukon River supports five species of Pacific salmon and large numbers of non-salmon species such as burbot, Dolly Varden, Bering cisco, humpback whitefish, northern pike, broad whitefish and sheefish. Salmon runs begin in mid May with the arrival of king and chum salmon followed by pink, sockeye and, lastly, coho salmon. An abundance of pink salmon return to the lower river during even numbered years, while considerable populations of coho return to the Tanana River and Andreafsky River drainages of the Yukon. Only a few sockeye are caught in the Yukon each year. The Pilot Station sonar site was designed to estimate the upstream passage of king, chum and coho salmon. King and chum salmon support the river’s two primary fisheries and are known for migrating long distances. Some migrate as far as 2,000 miles upriver to spawn in tributaries in Canada. At the beginning of their journey, salmon that swim the furthest up the Yukon have the highest oil content.
In Alaska, Yukon salmon are harvested mostly within the river drainage and by commercial and subsistence fishermen. Sport fisheries also harvest some king and coho salmon, primarily in the Tanana River. The only personal use fishery is in the Fairbanks Nonsubsistence Area along the Tanana River. The Yukon River drainage supports a substantial subsistence fishery, with approximately 12,000 Alaskans subsistence fishing its waters. Among natives, subsistence fishing not only provides food, but is of traditional and cultural significance. Often two or three households of extended family will work together in harvesting, cleaning and preserving subsistence-harvested fish.
King and chum salmon management
In the Yukon River, king and chum salmon are managed mostly according to tributary-based goals rather than a drainage-wide goal. For king salmon, there is no drainage-wide goal, but only individual tributary goals and a Canadian border passage goal. Similarly, summer chum salmon are managed based on individual tributary goals, however, there is also a minimum number of summer chum that must pass the Pilot Station sonar site before commercial chum fishing can begin. For fall chum salmon, there is a drainage-wide sustainable escapement goal of 300,000 to 600,000 fish. Managers can determine if this goal has been met by examining estimates of harvest and individual tributary goals including the Canadian border passage goal or, preliminarily, by examining harvests and Pilot Station sonar estimates. Coho salmon are managed partially based on Pilot Station sonar estimates in combination with harvest and escapement data, however, only one tributary sustainable escapement goal exists high in the drainage.
Because Yukon king and chum salmon provide for the livelihood of people living in Alaska and in Canada, they are also jointly managed under an international agreement. Under the Yukon River Salmon Agreement (PDF), the US and Canada have agreed to manage their fisheries to ensure enough salmon are available to meet escapement requirements and to share the fish available for harvest.
About 50 percent of Yukon king salmon, and 25 percent of fall chum salmon come from Canadian-origin stocks. Canadian-origin king salmon arrive early in the season, whereas Canadian-origin chum salmon arrive as a component of the fall chum run. King salmon migrations enter the river from mid May through mid July. Summer chum enter the river from June through mid July, followed by fall chum, which enter the river from July through early September. The fall chum run is generally much smaller than the summer run.