Development of Rations for the Enhanced Survival of Salmon, 1986-1987 Progress (Annual) Report.

The nutritional quality of feed plays an important role in determining the health and fitness of smolts. Commercial fish meal, the major source of protein in salmon rations, is subject to heat damage during drying and chemical interaction of fat oxidation products with proteins. Protein bioavailability is reduced and dietary stress may be introduced into hatchery feeds. This investigation tests the hypothesis that ration protein quality can influence the survival of smolts and the ultimate return of adults. Improved survival production would be better able to reestablish natural runs of salmon in the Columbia River system and maintain and improve the genetic integrity of specific stocks. The general approach being used involves a comparison of coho and chinook salmon reared on rations containing very high quality protein derived from vacuum dried meals and commercial rations relying on commercial fish meal as a source of protein. Survival and return of replicate brood-years of coded wire tagged test and control fish are being used to determine the influence of ration on survival. Project rearing and release of tagged fish to date include 1982, 1983, 1984 and 1985-broods of coho salmon; the 1983 and 1984-broods of fall chinook (tule stock) salmon; and the 1985 and 1986-broods of fall chinook (up-river-bright stock) salmon. This report covers the rearing and release of the 1985-brood coho and the 1986-brood fall chinook (up-river-bright stock) salmon