The search for trout redds in the middle Clark Fork is 

 hindered during both rainbow and brown trout spawning periods 

 by poor visibility in deep water areas where spawning could 

 occur. Visibility is sometimes precluded even in shallow 

 water during the rainbow trout spawning period due to highly 

 turbid spring runoff conditions. For this reason, use of the 

 Clark Fork for trout spawning is also being evaluated by 

 electrofishing during the spawning periods in an attempt to 

 locate concentrations of mature fish in spawning condition. 



Suitable rainbow, westslope cutthroat, and brown trout 

 rearing habitat is found primarily along the edge of the 

 Clark Fork's channel. Limited electrofishing surveys of 

 this habitat indicated young-of-the-year trout were rela- 

 tively more abundant in the Milltown and Superior study 

 sections than in the Missoula and Huson sections during late 

 summer of 1985 (Table 2-19) . Young-of-the-year trout were 

 relatively scarce in all four study areas (Berg 1983) . 



TABLE 2-19. AVERAGE SIZE AND RELATIVE ABUNDANCE OF YOUNG-OF-THE-YEAR TROUT 

 SAMPLED BY ELECTROFISHING 



Study 

 Section 



Date 



Trout 

 Species 



Average 

 Length (mm) 



Juveni le Trout 



E I ectrofi shed/Hour 



7.1 



10.1 



1.7 

 10.0 



1.4 

 0.0 



3.6 

 0.3 



14.6 

 1.1 



Source: Berg 1986a. 



2-34 



