physical habitat characteristics and attributes of fish 

 populations. 



Table 2. Gamefish species composition in five reaches of the 

 Blackfoot River based on data from 1981 through 1988. 



Percentage 



Reach Rb LL Ct DV Eb 



Mouth to Belmont Cr. 86 19 4 

 Belmont Cr. to Monture 58 38 2 2 

 Monture Cr. to Nevada Cr 20 71 9 

 Nevada Cr. to Lincoln 97 1 1 1 



Lincoln to Headwaters 53 1 46 



Species codes: Rb = rainbow trout; LL = brown trout; Ct 

 cutthroat trout; DV = bull trout; Eb = eastern brook trout. 



Reach 1 : Headwaters to Lincoln 



(RM 132.4 to RM 110) 



Fish populations were sampled in three sections of this reach 

 including: Below Pop's Place, Flesher, and Hogum sections. Each 

 of these sections was sampled during the early 1970 's as well as 

 1988. Westslope cutthroat trout and eastern brook trout dominate 

 the headwaters of the Blackfoot River above Lincoln averaging 53 

 and 46% of the trout population, respectively. 



Cutthroat trout densities have declined significantly since 

 estimates were conducted during the early 1970's (Figure 6). The 

 Below Pop's Section declined from 101 cutthroat age I and older 

 in 1971 to 15 per 1,000 ft of stream in 1988. A similar trend 

 was observed in the Flesher section where densities declined 

 from 69 per 1,000 ft in 1973, to 30 in 1975, and 15 per 1,000 ft 

 in 1988. In the Flesher section the 1975 sampling occurred after 

 the Mike Horse Mine tailings pond failure, which released large 

 quantities of toxic metals into the upper Blackfoot River. 



The density of cutthroat trout in the Hogum section has not 

 significantly changed between sampling periods. Cutthroat 

 density (yearlings and older) ranged from 14 to 17 per 1,000 ft 

 of stream. This section is dominated by shallow riffle habitat 

 with very little cover which probably explains the low densities 

 observed there. 



Eastern brook trout populations have significantly declined 

 in three of the four sampling sections in this reach (Figure 7) . 

 Brook trout (yearlings and older) in the Below Pop's Place 

 section, the uppermost sampling site in the drainage, did not 

 significantly change compared to the 1971 sampling. Densities of 

 YOY brook trout in 1988, however, were significantly higher 



14 



