40 

 30 

 20 

 10 

 

 30 

 20 



I 



z 

 o 



^20 



UJ 



^ 10 



Table 5. — Survival from egg to seaward migrant for five 

 species of Pacific salmon 



§30 



I— 



§20 

 o 



^ lOh 







30 

 20 

 10 







1961 



1962 



1963 



7 14 21 28 5 12 19 26 2 9 < 

 APRIL MAY JUNE 



PERIOD ENDING 



Figure 9. — Seasonal distribution of Yakima River spring 

 Chinook salmon captured during their seaward migration 

 at Prosser, 1959-63. 



been when the fish spawned in late September 

 (Quentin Edson).^ In subsequent years, per an 

 agreement between the State of Washington 

 Department of Fisheries and the U.S. Bureau of 

 Reclamation — the agency controlling the flow of 

 water over Easton Dam, a relatively uniform 

 minimum flow was maintained from September 

 until February when the young fish emerge from 

 the gravel. 



Estimates of survival from the egg to the sea- 

 ward migrant stage for Pacific salmon are sum- 

 marized in table 5. Prior to the present study, 

 survival of chinook salmon had been estimated 



Species and location 



Survival, egg to 

 seaward migrant 



Range 



Aver- 

 age 



Period 



Source of 

 iufonnatiou 



' Quentin Edson, Fishery Biologist, City of Tacoma, Department of 

 Public Utilities, Tacoma, Washington. Personal commmiication. 



„ , , Percent Percent Years 



Sockeye salmon; 



Cultus Lake, B.C 1.01-3.22 1.87 4 Ricker, 1966 



Babine Lake, B.C 1.34-5.18 3.77 5 Do 



Lakelse Lake, B.C 60-5.05 1.86 7 Do 



Port John Lake, B.C 3.00 (>) Do 



Chilko Lake, B.C 8.00 (i) Do 



Dalnee Lake, U.S. S.R. .005- 1.05 .28 10 Hanam'ura. 1966. 



Pink salmon: 



McCIinton Creek, B.C. 6.90-23.80 (') 6 Neave, 1966a 



Morrison Creek, B.C... 4.70-6.70 (i) 2 Do 



Hooknose Creek, B.C.. .90-37.20 (i) 13 Do 



Lakelse River, B.C 18.00 (■) i Do 



Kisplox River, B.C 23.00 (i) i Do. 



Kitwanga River, B.C.- 15.00 (■) 1 Do 



Wahleach Creek, B.C.. 37.00 (i) i Do 



Sashin Creek, Alaska... .10-21.80 6.33 22 McNeil, 1966 



Karymai Spring, .02-5.70 1.96 6 Semko, 1954. 

 U.S. S.R. 



Chum salmon: 



Nile Creek, B.C.. 08-13.60 (i) 8 Neave, 1966b. 



Hooknose Creek, B.C.. .96-22.00 13 Do 



Karymai Spring, . 68- 4. 20 2. 16 7 Semko,' 1954. 

 U.S. S.R. 



Coho salmon: 



Nile Creek, B.C... 76-2.10 1.27 4 Godfrey, 1965 



Hooknose Creek, B.C.. .70-3.96 1.30 10 Do 



Minter Creek, Wash .70-9.65 1.71 11 Do 



Waddel Creek, Calif 1.16-1.56 1.43 4 Do. 



Chinook salmon: 



Fall Creek, Calif. 7. 00-32. 00 14. 50 4 Wales and Coots 



1955. 



Yakuna River, Wash. . 5.35-16.35 10.70 5 Present study. 



' Not reported. 



only in Fall Creek, Cahf., and the usefulness of 

 these values is limited. FaU Creek is a small 

 atypical spawning stream and the progeny of the 

 Fall Creek chinook salmon population migrate to 

 sea in their first year of life (a characteristic of 

 fall chinook, pink, and chum salmon, but not of 

 spring or summer chinook salmon; the latter 

 races, like sockeye and coho salmon, usually 

 spend 1 year or more in fresh water before mi- 

 grating to sea). 



Relative to all other species, the limits within 

 which the percentage survival of spring chinook 

 salmon in the Yakima River fluctuates are neither 

 wide nor narrow but reasonably moderate. Egg-to- 

 migrant survival of spring chinook salmon in the 

 Yakima River is generally higher than that for 

 sockeye salmon and coho salmon — other species 

 whose young spend 1 year or more in fresh water. 

 The resiflts of the various studies are not strictly 

 comparable, however, because migrants are trapped 

 at varying and sometimes unspecified points in 

 time and distance from the nursery areas and the 

 sea. Young spring chinook salmon trapped at 

 Prosser must yet migrate 600 km. to the sea. 



EGG-TO-IIIGRANT SURVIVAL OF SPRING CHINOOK SALMON IN YAKIMA RIVER, W^ASH. 



357 



