Table 5. — Semimonthly number and percent of chlnook salmon jacks counted over each fish ladder. 



Rock Island Dam, 1965 



Sockeye, Oncorhynchus nerka 

 (Blueback or Red) 



The sockeye count of 42,379 was about 81 

 percent of the 32-yr. average of 52, 159 (table 1) 

 and less than the 1964 run by 27,032 fish. 

 Peak of the run was reached on July 16, when 

 2,863 fish were counted through the fishways. 

 Peak daily count in 1964 occurred on July 27 

 when 6,247 fish were recorded. 



Of the sockeye passing Rock Island Dam in 

 1965, about 69 percent ascended the left lad- 

 der, while 18 and 13 percent ascended the 

 middle and right ladders, respectively (table 6). 

 Percentage distribution of sockeye through 

 left, middle, and right fishways in 1964 was 

 about 66, 15, and 19, respectively. 



Data pertaining to sockeye daily counts are 

 in tables 9-14. Monthly totals of sockeye 

 counted in 1965 (table 2) show 82 percent of 



Table 6. 



-Semimonthly number and percent of sockeye salmon counted over each ladder. Rock 



Island Dam, 1965 



