Orsi and Jaemcke Marine distribution and origin of prerecruit Oncorhynchus tshawytscha 



491 



Growth rates were significantly higher (f-test, 

 P<0.05) for ocean- than for stream-type CWT chinook 

 salmon in four of the seven growth periods exam- 

 ined (Fig. 6). Sample sizes of certain age groups of 

 fish in the three growth periods with no statistical 

 significance were extremely limited (4 or less), al- 

 though ocean-type chinook salmon in those cases also 

 had higher growth rates than had stream-type fish. 

 Mean growth rates generally declined as age in- 

 creased and season progressed for ocean-type (2.35, 

 1.54, 1.20, 0.97, 0.71, 0.74, and 0.69% body wt/d) and 

 stream-type (1.85, 0.99, 0.88, 0.78, 0.63, 0.64, and 

 0.58% body wt/d) chinook salmon (Fig. 6). 



Discussion 



This study has described the initial marine occur- 

 rence and distribution of ocean-type chinook salmon 



of non-Alaska origin in marine waters of southeast- 

 ern Alaska. During earlier research on prerecruit 

 chinook salmon in the central and northern regions 

 of southeastern Alaska in May and September, Orsi 

 et al. (1987) caught age 0.1 chinook salmon of non- 

 Alaska origin in September, but not earlier. In our 

 study, we caught age 0.1 non-Alaskan stocks of 

 chinook salmon in the southern region in February, 

 May, and September (Table 6). Consistent with Orsi 

 et al. (1987), we also found an influx of non-Alaska 

 age 0.1 chinook salmon by September in the central 

 and northern regions (Table 6). We found age 0.2 

 chinook salmon of non-Alaska origin throughout 

 marine waters of southeastern Alaska each season. 

 Age 0.2 chinook salmon reach the minimum harvest 

 size limit in the southeastern Alaska troll fishery in 

 June and July ( Olsen, 1992 ), and age 0.3 fish are the 

 predominant harvest component (Van Alen and 

 Olsen, 1986; Van Alen etal., 1986, 1987). Thus, non- 



