STATION rNiwMP.FRS 



2 4 6 8 10 12 14 16 18 20 



DECEMBER 9- ,2 



PiQUBE 7. — Continued 



Eagle Creek Population 



The principal migration of spring cliinook salm- 

 on from Eagle Creek into the reservoir was in 

 the fall and consisted of age-group O fish, 53 to 

 125 mm. long. This movement was followed by a 

 second lesser migration of age-group I fish, 65 to 

 138 mm. long, from February to May (Krcma and 

 Raleigh, 1970). Only chinook salmon tliat had 

 held over from the spring migrations were foimd 

 in significant numbers in the reservoir at that time 

 of year. These populations were separable by size 

 (fig. 9). 



Continuous recovery from the upper Powder 

 River Arm and the main reservoir of marked age- 

 group O fish from the fall migration from Eagle 

 Creek indicated that not all these fingerlings con- 

 tinued to move through the reservoir. Further evi- 

 dence was obtained by comparing mean lengths of 

 fish caught leaving Eagle Creek with those of fish 

 from the reservoir. Fish that remained in the 

 stream grew little through the fall and winter, 

 whereas those in the reservoir continued to grow. 



Incidental movement of Eagle Creek fish from 

 the reservoir began in November, but a sustained 



JUVENILE SALMON DISTRIBUTION AND MOVEMENT IN BROWNLiEE RESERVOIR 



229 



