FISHERY BULLETIN: VOL. 76, NO. 1 



was discontinued after 1966 and the Alaska troll 

 fishery sampling stopped after 1967. Over the 7 yr 

 of sampling, 3.3 million chinook salmon were 

 examined for marks and 208,000 were sampled for 

 age. This was an average sampling percentage of 

 20 and l^r for marks and age, respectively. The 

 yearly mark sampling rate ranged from 14 to 28% 

 of the catch and the age sampling ranged from 1 to 

 4%. 



Enumeration of Returns 



Returns to all study facilities were counted and 

 examined for marks. Age, length, and sex data 

 were also collected from 25 to 50 unmarked 

 chinook salmon/wk at each hatchery. Returns to 

 five other Columbia River hatcheries ( Abernathy, 

 Speelyai, Toutle, Klaskanine, and Sandy) were 

 also examined for marks. Total hatchery returns 

 for the 1961-64 broods of fall chinook salmon were 

 155,783, of which 8,527 were marked. 



Hatchery and adjacent fall chinook salmon 

 spawning streams were surveyed to estimate 

 natural spawning of hatchery fish. The Klickitat, 

 Big White Salmon, Little White Salmon, Wind, 

 Washougal, Kalama, Lewis, Elokomin, and Grays 

 Rivers and Plympton and Big Creeks were sur- 

 veyed in 1964, 1965, and 1966. The surveys were 

 designed to estimate the total spawning popula- 

 tion and to gather mark, age, and length data. 

 During the 3 yr, 62,400 chinook salmon were 

 examined of which 1,600 were marked. The 

 stream surveys were discontinued after 1966 be- 

 cause of a funding reduction. 



INDIVIDUAL HATCHERY MARK 



CATCH AND POTENTIAL 

 CONTRIBUTION, 1961-64 BROODS 



In this study 12 hatcheries and one rearing pond 

 were marked with a common mark for four brood 

 years. All but two of these facilities (Big White 

 Salmon Pond and Washougal Hatchery) had a por- 

 tion of at least one brood year's production marked 

 with a special mark. A portion of all four brood 

 years' production at Spring Creek and the two 

 Kalama River hatcheries were marked with spe- 

 cial marks. This special marking was done to give 

 an indication of the migration patterns and con- 

 tributions to the fisheries for each individual 

 hatchery in the study. The estimated catches and 

 potential contributions will now be presented for 

 each hatchery with special marks. 



192 



Spring Creek National Fish Hatchery, 

 1961-64 Broods 



Spring Creek Hatchery was allocated the Ad, 

 LV, combination mark for the four brood years. 

 The RM mark was used in combination with the 

 Ad-LV mark for the 1961 and 1963 broods and the 

 LM mark was used with the 1962 and 1964 broods. 

 Approximately 10% of Spring Creek's production 

 was marked for each brood year. The number of 

 fish given special marks ranged from 1.1 million 

 for the 1961 brood to 600,000 for the 1964 brood. 



Spring Creek special marked chinook salmon 

 were available to the ocean and Columbia River 

 fisheries from 1963 through 1969. During this 7-yr 

 period, we estimated 12,180 special marked fish 

 were recovered in the fisheries (Table 8 ). Over 65% 

 of the fish were captured in their third year of life, 

 with nearly 27% taken as 4-yr-olds. Ocean re- 

 coveries occurred primarily from the Columbia 

 River mouth north to the west coast of Vancouver 

 Island. Fisheries in the marine areas took 74% of 

 the fish, with 26% being caught in the Columbia 

 River commercial fisheries (Figure 3). 



The potential contribution of Spring Creek 

 chinook salmon (had no marking taken place) was 

 estimated at 401,700 fish for the four broods com- 

 bined. The average Spring Creek contribution to 

 the fisheries for the four broods combined was 12 



Figure 3.— Percentage of catch of 1961- to 1964-brood fall 

 chinook salmon from Spring Creek National Fish Hatchery 

 taken by area and fishery, 1963-69. 



