Yukon River Fall Chum Salmon Fisheries: Management, Harvest, and Stock Abundance
Fred J. Bue, Bonnie M. Borba, Richard Cannon, Charles C. Krueger
Abstract.—The most abundant salmon of the Yukon River is chum salmon Oncorhynchus keta, which make annual spawning runs from the Bering Sea up the Yukon River, traversing more than 1300 river miles across Alaska into Yukon Territory in Canada. Genetically distinct summer and fall runs exist and these runs are differentiated into stocks by timing of migration and by spawning river. The fall-run stocks are harvested from mid-July through early October and most Yukon River fisheries occur on a mixture of populations or stocks. This paper provides descriptions of fall chum salmon life history, the Yukon River fishery and its management, changes in stock abundance over time, and harvest. Six fisheries occur for fall-run chum salmon: subsistence, personal use, aboriginal, domestic, sport, and commercial. Subsistence fisheries in Alaska are comparable to aboriginal fisheries in Canada, as are personal use, sport, and domestic fisheries. The fisheries use a variety of gear including gillnets and fish wheels. Jurisdictionally, management requires cooperation among state, federal, and international organizations during both the ocean and river phases of the salmon life history. The goal of management is to regulate the harvest of commercial and traditional-use fisheries to provide an adequate number of fish for spawning (escapement) to ensure the reproduction of the next generation, and to sustain Alaskan and Canadian fisheries. Subsistence and aboriginal fisheries have priority over other fisheries in allocation of harvest. Regulations are used to control how many fish are caught through restrictions on effort, fishing efficiency, and the scheduling of where, when, and how long fishery openings will be allowed. Over the period 1974–2008, the largest runs of fall chum salmon occurred in 1975, 1995, and 2005 (> 1.47 million fish) and smallest runs occurred in 1999, 2000, and 2001 < 334,000 fish). Odd-year runs tend to be larger than even-year runs. The run failures of 1998–2002 were followed by increased run numbers in 2003–2008. Primary variables that influence the total run of fall chum salmon are the spawning success of previous generations, natural variability in marine and freshwater survival due to climatic and oceanographic processes, and fishery harvests in both marine and freshwater. Salmon escapement numbers typically emulated total run estimates. Every river monitored had low estimated escapements from 1998–2002. From 1974–2008, total harvest of fall chum salmon in Alaska (average 291,982 fish) exceeded Canadian harvests (average 20,314 fish) by an order of magnitude. Some lessons learned from management of this fishery are offered that may be applicable to other fisheries: stakeholder involvement is critical to effective harvest management; rapid, effective information sharing is a requirement for fast-paced, in-season decision-making; limited entry alone did not control harvest; and some things that make management difficult just cannot be changed!