other Species of Fish 



In 1965, species of fish passing Rock Island 

 Dam other than salmon and steelhead were 

 counted as in former years (tables 15-20). 

 No claims are made as to connplete accuracy 

 of identification of these fish; however, the 

 degree of accuracy is consistent with that 

 maintained at other dams on the Columbia 

 River. Such data should only be used as a rough 

 index of abundance of these fish. 



In 1965, 1 15,045 fish other than salmon and 

 steelhead passed Rock Island Dam. This num- 



ber, as compared to 118,284 in 1964, exceeded 

 the count of salmon and steelhead by about 

 30,000. The species included are largescale 

 sucker, Catostomus macrocheilus ; longnose 

 sucker, Catostomus catostomus ; squawfish, 

 Ptychocheilus oregonense ; Rocky Mountain 

 whitefish, Prosopium williamsoni ; Columbia 

 River chub, Mylocheilus caurinus ; carp, 

 Cyprinus carpio ; lamprey, Entosphenus tri- 

 dentatus ; Dolly Vardentrout, Salvelinus malma; 

 and rainbow trout, Salmo gairdneri. 



Table 15 Other species of fish coimted, Rock Island Dam, May I965 



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