93 



CONCLUSIONS 



Clark Canyon Reservoir develops a thermocline, turning over in spring 



and fall. The reservoir can be classified as a fertile environment. 



White sucker was the most numerous fish species netted in the reservoir 



between 1964 and 1972, comprising from 40 to 93% of the net catches. 



Hatchery rainbow trout comprised over 90% of the annual catch of 



game species by anglers. An estimated 41,000 and 39,000 rainbow 



trout were harvested in 1971 and 1972, respectively. Brown trout and 



burbot were also taken. 



Few carp have been observed in the reservoir. Their impact on the 



trout fishery appears negligible. 



Reservoir populations of white and longnose suckers use Horse Prairie 



Creek for spawning. 



Conflict between resident trout populations in Clark Canyon trib- 

 utaries and spawning populations of suckers could not be determined 

 from limited biological data collected in this study. 

 Preimpoundment populations of trout in the Red Rock River appear to 

 be greater than those after impoundment. However, this may reflect 

 habitat differences rather than factors related to impoundment. 

 Growth of hatchery rainbow trout during their first year in the 

 reservoir is dependent on planting time. 



Estimates of fishing pressure in fisherman days were 30,400 in 

 1971, 36,000 in 1972, and 40,587 in 1975-76 (May-April). Fishing 

 pressure increased by approximately 34% over a 6-year period. 



