107 



COHO HATCHERY PRODUCTION 



I 1 Off«titi«m t:y/fiot*il 

 T77Z On-aucion fxy/flM*xlla«at 



t 1 Off-tUUOB MDlU 



i •] 



"siiBS 



SiiaMlll 



1M4 l»ss 1»'» »•»• »»•« 



Brood yomx 



Figure II. Hslcaery-resred coho rcksses into (be Cbehsiis Buta 

 (WDF unpublished d«u). 



The modern hatchery chum program 

 began at Simpson Hatchery in 1965. 

 Releasee were particularly heavy 

 between 1978 and 192. (Figure 19), 

 The last chum return ng to the 

 hatchery was records., tr. 198" 

 production was diacc tinusd at that 

 point (WDF unpublish d records). 



Mister Staelhead 



Cfc'j* Sxljeon 



Figure 19. rUuhcry-resrcd chum seimon released imo the Qichihi 

 Bum (WDF unpublished d*u). 



Winter-run steeihesd production has been 

 emphasized in .i&tchery programs. Small 

 numbers were released annually since the 

 early 1950s, but the program has grown 

 eir.ee 1970 (Figure 20). In 1975, on- 

 st&ti?r releasee became a significant 

 part of production, and continue to make 

 uj. about a third of each year's 

 releases. 



Fifure 20. Hsicherr-rtsred wiser ■ osfc —d released into lae 

 CfcchiKi Basin (WDW uapublisbed data). 



50 



