Orsi and Jaenicke: 



Marine distribution and origin of prerecruit Oncorhynchus tshawytscha 



487 



were not as great among age -.2 fish as among 

 younger fish, especially in September. Some age -.2 

 fish were probably not caught effectively then, ow- 

 ing to the small gear used; therefore the lengths of 

 age -.2 chinook salmon in September did not extend 

 far above one standard deviation from the mean (Fig. 

 3). Conversely, the lengths of age 0.0 chinook salmon 

 caught in September, which did not extend far below 

 one standard deviation from the mean, suggest that 

 fish <15 cm FL were too small for our gear or were 

 absent. 



The overall sex ratio of the 539 CWT chinook 

 salmon was nearly equal to 1.0, namely 275 males to 

 264 females. There were, however, significant differ- 

 ences in proportion of males by ocean-age group in 

 September (X 2 , P<0.01) and May (X 2 ,P=0.05) but not 

 in February (X 2 , P=0.75 ). Percentage of males for each 

 ocean age by season were as follows: September, age 

 -.0 (57%), age -.1 (41%), and age -.2 (23%); May, age 

 -.1 (56%) and age -.2 (40%); and February, age -.1 

 (56% ) and age -.2 (52%). Of the CWT chinook salmon 

 examined, most were immature; only a few age -.1 

 and -.2 males sampled in May were qualitatively as- 



sessed as maturing on the basis of coloration, shape, 

 or enlarged gonads. 



Origin and distribution 



According to CWT recoveries, prerecruit chinook 

 salmon in southeastern Alaska were from 74 stocks 

 originating from Oregon to the northern region of south- 

 eastern Alaska, a range of 1,800 km (Table 4; Table 5). 

 Most stream-type chinook salmon of Alaska origin 

 were caught in inside waters, whereas ocean-type 

 fish of non-Alaska origin were slightly more abun- 

 dant in outside than in inside waters (Fig. 4; Table 

 6). Most age -.0 stream-type chinook salmon from 

 Alaska and British Columbia stocks were caught in 

 inside waters, whereas those from Washington and 

 Oregon stocks were caught in both inside and out- 

 side waters (Fig. 4; Table 6). Only two CWT age -.0 

 ocean-type chinook salmon were sampled; both were 

 experimental hatchery releases from Alaska stocks 

 caught in inside waters. Age -.1 and -.2 stream-type 

 chinook salmon were mainly from Alaska stocks and 

 were caught at a higher rate in inside waters than 



