322 FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Table 11. — Chronology of spawning runs and average daily water temperatures (° F.) for the Grebe Lake stream system (1963) 



' Movements recorded were upstream only in the creeks, but both directions in the outlet, as indicated. 



Table 12. — Chronology of spawning runs and average daily water temperatures (° F.) for Grebe Lake (1964) 



i Movements recorded were upstream only in the creeks, but both directions In the outlet, as indicated. 



Table 13. — Comparison of spawning migrants based on weir counts made in 1953 and 1954, Grebe Lake system 



trout spawned in Grebe Lake tributaries. How- 

 ever, these observations were limited to fish enter- 

 ing the Hatchery Creek weir. In 1953, only 18 

 of the 5,434 fish which entered this particular trap 

 were hybrids. Spawning trout were relatively 

 more numerous than this in other waterways, 

 but no two streams gave identical indexes of 



relative abundance of the two species. In the 

 outlet, the Gibbon River between Grebe and Wolf 

 Lakes, hybrid trout comprised 41 percent (183 

 individuals) of the population migrating down- 

 stream in 1953 and 18 percent (143 specimens) 

 1954 (table 13). Approximately 50 percent 



in 



of the fish coming upstream each year were trout; 



