STATION NUMBERS 

 Q 2 4 6 8 10 12 14 16 18 20 2 4 G 8 10 12 14 16 IS 20 



* r' ' ' ' surface' frcJ; 



iZEN 



2 4 6 8 10 12 14 16 18 20 

 -H — ji — r-l ' *— ; — I 1 — V"" *— 1 — ' 



^ ----6 ^ ^6- 



2 4 6 8 10 12 14 16 18 20 



JUNE 4-10 



PiotTBE 7. — DisaolTed oxygen (p.p.m.) profiles from Brownlee Reservoir, 1963, modified from Ebel and Koeki 



(1968). 



the reservoir with little wandering and corrobo- 

 rated the estimated rates of movement. 



In 1962, about 3,200 fish from the Weiser River 

 population were marked as they were entering the 

 reservoir. Six were recaptured the following 

 spring (1963) in the reservoir. In 1963, about 1,900 

 fish were marked during their migration into the 

 reservoir; in late June and July, 23 were recap- 

 tured in the Snake River. A study of growth 

 patterns on their scales showed that they had re- 



turned upstream from the reservoir. These recap- 

 tures indicate that some fish of the Weiser River 

 population become disoriented and hold over in the 

 reservoir, but this behavior did not appear to be 

 a major factor in the general movement of this 

 early migrating population of large yearling fish. 

 In general, the Weiser River chinook salmon 

 passed through a more benign environment in the 

 reservoir than did populations migrating later in 

 the season ( figs. 6 and 7 ) . 



228 



U.S. FISH AND WILDLIFE SERVICE 



