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Fishery Bulletin 93(2), 1995 



1983, and 1985, respectively, and 5.7%, 12.5%, and 

 7.8% of the total ocean catch in June 1982, 1984, and 

 1985, respectively (Table 3). These percentages of 

 CWT fish were much higher than those of down- 

 stream migrant yearling chinook salmon entering the 

 Columbia River estuary, which averaged 2.3% CWT 

 fish during the period January^June, 1981-83 (cal- 

 culated from Dawley et al., 1985, a and b), and were 

 comparable to the CWT percentages of hatchery year- 

 ling Columbia River spring and fall chinook salmon 

 released during the period April-June 1982—83 (3.7 

 and 8.0%, respectively, Table 1). The high proportion 

 of CWT yearling (age 1.0) chinook salmon from the 

 Columbia River basin in the May and June ocean 

 catches indicates that most unmarked fish caught 



in the ocean during these months probably were also 

 yearling hatchery fish from the Columbia River basin. 

 Five stocks from the Columbia River basin domi- 

 nated our catch of age-1.0 smolts: Snake River sum- 

 mer, Upriver Bright (URB) and Snake River fall 

 chinook salmon, and Cowlitz River and Willamette 

 River spring chinook salmon (Table 4). These stocks 

 are caught in ocean fisheries as maturing fish mainly 

 to the north of Oregon (Howell et al. 7 ). 



Catch per unit of effort of CWT Fish 



Some distinct seasonal trends were apparent in the 

 abundance of the different age classes of CWT fish. 

 Age-1.0 fish were most abundant in catches in May 



