KARLUK RIVER RED-SALMON INVESTIGATION 



39 



Table 5, from which it appears that the predominating age group is the 5 3 's — fish 

 that migrated seaward as fingerlings in their third year and matured and entered the 

 run in their fifth year. Eighty-five per cent of our material belongs to this group 

 and must therefore have developed from eggs laid down in 1911, when the Karluk 

 red-salmon pack amounted to 124,000 cases. The only other age groups repre- 

 sented in significant numbers are the 6 3 's and 6 4 's, and as both of these matured in 

 their sixth year, they developed from the brood year 1910. Together, they com- 

 prise 13 per cent of the samples obtained, a not unusual proportion of 6-year fish 

 in runs of other years. The pack of red salmon in 1910 amounted to 107,000 cases, 

 and while the 6-year progeny of that year appear in normal numbers in the run of 

 1916, the 5-year group, which probably was largely responsible for the run of 1915, 

 was very limited, if we judge from the 1915 pack, which was of only 59,000 cases. 



Table 5. — Random samples of the Karluk red-salmon run of 1916, distributed by age groups, sex, and 



length 



[M = male; F = female] 



Length in inches 



Age group and sex 



4i 



4, 



5j 



54 



6 3 





TotuJ 



F 



M 



F 



M 



F 



M 



F 



M 



F 



M 



F 



18 



























18>2 - — 







1 









1 













19 























am 





1 























20 



1 























20K 

























21 











4 

 5 

 19 

 27 

 41 

 39 

 45 

 14 

 6 

 1 

















21H - 









1 



1 



1 













22 



















22H - 









1 

 7 

 8 

 20 

 19 

 29 

 25 

 9 

 4 

 1 













3 



10 



3 

 4 

 2 





23 









1 





1 



1 







23H - 











2 

 5 

 3 

 6 

 1 





24 















1 





m 

















25 













1 

 1 



1 



3 

 1 





25^ 

















26 

















28H - 















1 









27 























Total 

























1 



1 



1 



124 



201 



2 



2 



4 



i 



17 



22 



382 





The 1917 run is represented in our material by the following samples: 



Individuals 



July 10 249 



Aug. 18 100 



Aug. 23 99 



Aug. 25 210 



Aug. 26 100 



Total 758 



As indicated in Table 6, the proportions of the principal age groups in 1917 are 

 very similar to those obtaining in our samples for 1916. The 5 3 group is again 

 dominant and comprises 88 per cent of the whole, while the two 6-year groups (6 3 

 and 64) together amount to 10.4 per cent. An unusually large proportion of the 

 1917 run is thus seen to be derived from the spawning of 1912, a year in which the 

 commercial take was rather poor (89,000 cases). Whether the spawning escapement 



