Washington purse seine 3.16 



Washington reef net 2.14 



Hatchery production. — Releases from Columbia River hatch- 

 eries above Bonneville Dam were weighted by subtracting 10% 

 (a generally accepted mortality rate) of the figure reaching each 

 dam downriver of the point of release from the total arriving at 

 the dam, to compensate for juvenile mortality associated with 

 turbine passage. For example, if 10,000 kg were released at a 

 point upriver of three dams, the amount reaching the ocean was 

 estimated at 7,290 kg: 



Dam 1 . 



. 10,000 - 



- 0.1 (10,000) = 



9,000 



Dam 2 . . 



. 9,000 - 



- 0.1 (9,000) = 



8,100 



Dam 3 . . 



. 8,100 - 



- 0.1 (8,100) = 



7,290 



Surface sea temperature during period of out-migration. — 



The studies by Vernon (1958) and Van Hyning (1968) both 

 implicated warm surface sea temperature at Amphitrite Point 

 during June of year / — 2 as a negative factor affecting juvenile 

 survival. The possibility of a relationship between ocean fishing 

 success and this variable was evaluated by calculating regres- 

 sions of 1) commercial ocean troll catch, 2) troll CPUE, and 3) 

 ocean sport catch during year i on mean sea temperature there 

 during June and June through August of year i— 2. 



Upwelling during period of out-migration.— We calculated 

 regressions of 1) commercial ocean troll catch, 2) troll CPUE, 

 and 3) Washington ocean sport catch in year / on indices of 

 upwelling during April through June in year i— 2 off Cascade 

 Head and Cape Flattery. Upwelling indices are listed in Table 4. 

 Since surface salinity is a good indicator of the extent of up- 

 welling (Owen 1968), regressions were calculated of these depen- 

 dent variables on ranked values (1 = lowest °/ oa ) of salinity at 

 Amphitrite Point during June through August of year / - 2; the 

 base data are contained in sources listed previously. 



Upwelling during current season. — We calculated the regres- 

 sions of 1) Columbia River district commercial troll catch, 2) 

 Columbia River district troll CPUE, and 3) combined sport 

 catch for llwaco and Westport in year i on indices of spring 



(April-June) upwelling off Cascade Head in year i. Regressions 

 of 1) Puget Sound district commercial troll catch, 2) Puget 

 Sound district troll CPUE, 3) Canadian troll catch in areas C, 

 21, and 23, and 4) combined sport catch during April through 

 October for La Push and Neah Bay in year ;' on indices of spring 

 upwelling off Cape Flattery in year /' were also calculated. 



Previous fishing success. — Several fisheries in the previous 

 year may function as test fisheries for chinook salmon. If the 

 assumption is valid that the troll fishery in Canadian areas 24-27 

 intercepts southward-bound Columbia River fall chinook 

 salmon in the fall of the year prior to their maturity, then troll 

 CPUE there may be an indication of probable chinook salmon 

 catches off the Washington coast in the following year. The 

 Puget Sound sport catch of chinook salmon is composed mostly 

 of fish 1 yr younger than those caught in the ocean. Annual 

 Puget Sound sport catch in year ; — 1 may then serve as an index 

 of abundance of Puget Sound-Fraser River chinook salmon that 

 will be in the ocean the following year. The Canadian purse 

 seine catch of immature chinook salmon (called jacks in 

 Canadian statistics) in Canadian area 20 during August of year 

 i— 1 could also be a potential indicator of ocean fishing success 

 the following year. We therefore calculated regressions of troll 

 catch, CPUE, and sport catches on these variables. 



Coho Salmon 



Indices of brood year abundance. — These consisted of 

 spawner density estimates, escapements, and net gear catch and 

 CPUE during peak run periods (Table 5), based on dates listed 

 below. 



Run 



Columbia River 

 Area 20 

 Puget Sound 

 Fraser River 



Inclusive dates 



1 October-30 November 

 1 August-31 October 

 1 September-31 October 

 1 September-31 October 



Table 5. — Indices of brood year abundance of coho salmon based on net gear catch 

 (in thousands of fish) and CPUE (in fish per standardized unit of effort). 























Combined Puget S.. 





Table 4. — Indices of 



upwelling. Modified from Gunsolus (1978). 



Brood 

 year 



Late-run 

 Catch 



Columbia R. 

 CPUE 



Puget Sound 



area 20, 

 Catch 



Fraser R. 





Catch 



CPUE 



CPUE 





Cascade Head 



Cape Flattery 



1953 



14.7 



3.71 







665.2 



9.8 



Year 



April index 



April-June 

 index 



April index 



April-June 

 index 



1954 

 1955 

 1956 

 1957 



10.0 

 15.0 

 17.1 

 13.8 



4.24 

 7.37 

 8.90 

 7.99 



297.2 

 453.8 

 187.7 



11.3 

 23.4 

 11.7 



420.5 

 614.9 

 581.9 

 696.9 



6.2 

 7.4 

 17.8 

 10.5 



I960 







32.5 



5 



22.0 



1961 



36 



22.0 



55 



25.5 



1958 



5.4 



4.23 



266.9 



10.7 



674.7 



8.4 



1962 



18 



41.0 



25 



32.0 



1959 



3.3 



4.10 



255.3 



13.3 



743.9 



10.9 



1963 



16 



40.0 



38 



42.0 



1960 



1.1 



3.93 



80.7 



8.5 



223.5 



6.4 



1964 



82 



95.5 



80 



68.5 



1961 



4.0 



8.37 



330.9 



20.2 



726.0 



14.6 



1965 



30 



98.5 



41 



76.5 



1962 



6.5 



10.21 



352.3 



20.5 



861.0 



17.3 



1966 



68 



103.5 



73 



68.0 



1963 



6.4 



12.13 



175.9 



11.9 



609.8 



9.2 



1967 



36 



122.5 



51 



84.3 



1964 



7.0 



12.27 



344.2 



23.4 



823.6 



20.5 



1968 



72 



93.0 



71 



59.5 



1965 



10.4 



15.85 



325.9 



21.6 



883.9 



17.4 



1969 



4 



37.0 







33.0 



1966 



6.8 



32.86 



572.8 



33.7 



1,227.1 



23.4 



1970 



50 



64.5 



64 



57.5 



1967 



8.1 



14.42 



241.2 



14.7 



777.3 



12.1 



1971 



23 



39.5 



27 



37.5 



1968 



3.2 



6.21 



403.1 



25.1 



920.9 



22.2 



1972 



24 



44.5 



36 



37.0 



1969 



3.2 



7.71 



284.1 



18.6 



617.5 



14.0 



1973 



68 



69.0 



64 



42.0 



1970 



29.0 



25.88 



778.4 



36.4 



1,402.8 



24.4 



1974 



27 



55.0 



38 



44.0 



1971 



32.1 



18.79 



475.5 



23.4 



1,213.7 



16.6 



1975 



60 



97.0 



58 



66.0 



1972 



9.0 



9.81 



522.0 



23.1 



784.1 



16.1 



