SEAWARD MIGRATION OF CHINOOK SALMON. 7 1 



also apparent that the fish from the lower tributaries of a river system \vill, in a general 

 way at least, migrate earlier than those from the higher tributaries. 



1 1 . Among the male fry which remain in fresh water over their first summer, about 

 lo per cent will mature precociously during the fall, the normal spawning period for 

 adult sea-run chinooks. The proportion of male frj' thus maturing presumably differs 

 in different streams. These precociously mature males may recover from the effects 

 of ripening the sex products, in this respect differing markedly from the known habits 

 of the sea-run fish. 



12. The suggestion is made that chinook fry be liberated from the hatcheries at 

 such a time as will enable them to migrate at the normal period for seaward migration 

 for the stream in question. 



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Calderwood, W. L. 



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(1911). The age and growth of salmon and trout in Norway, as shown by their scales. (Translated 

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 the Commissioner of Fisheries, Province of British Columbia, for 1913. 



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1904. Zur Alters und Wachstums Zerkennimg der Fische nach der Schuppe. Allgemeine 

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