Evaluation of the Contribution of Chinook Salmon Reared at Columbia River Hatcheries to the Pacific Salmon Fisheries. Annual Report FY 1985

摘要

FY 1985 was the seventh year of an eight-year study to determine the distribution, contribution, and value of artificially propagated fall chinook on the Columbia River. Tagging of hatchery fall chinook was completed in FY81. Sampling of sport and commercial marine fisheries from Alaska through California, Columbia River fisheries, and Columbia River hatcheries and adjacent streams occurred in 1985 as planned. Returns of fall chinook to Columbia River facilities as of September 30, 1985 are 85,222. This return is already larger than three of the past five years. Estimated Catches of coded wire tagged salmonids are available through 1983 for all fisheries except Alaska in 1981 and Washington in 1983. Catch proportions by fishery for the 1978 brood are .01, .41, .34, .07, 0, and .17 for the Alaska, Canada, Washington, Oregon, California, and Columbia River fisheries respectively. The proportion of recoveries for the four age groups of 1978-brook fish caught are .05, .63, .30, .01 for the two-through five-year-old chinook respectively. Contributions to the fisheries per 1000 fish released for all hatcheries combined are 2.7 and 3.6 for the 1978 and 1979 broods respectively. Four years (1980 to 1983) are included in the contribution values for the 1978 brood and three years (1981 to 1983) for the 1970 brood. Spring Creek Hatchery has the greatest contribution to the fisheries of 8.3 and 12.8 fish per 1000 fish released for the 1978 and 1979 broods respectively. The Spring Creek contribution is followed by Stayton Pond, Abernathy, Bonneville and Big Creek at 6.5, 4.2, 2.9 and 2.6 respectively for the 1978 brood and Big Creek, Stayton Pond and Abernathy at 8.4, 6.7 and 4.7 respectively for the 1979 brood. Other facilities have contributions per 1000 releases of approximately 2 or less. These contributions are minimums since all possible fisheries and catch years are not yet included. (ERA citation 11:036825)