compared to the 1971 sample (Appendix Table 3). 



Bull trout were rare in reach 1. Only one fingerling size 

 bull trout was captured in the Hogum, Flesher, and Below Pop's 

 sections combined in 1988. During 1972, seven bull trout were 

 captured in these sections (Appendix Table 1) . 



Catchable sized rainbow trout were planted throughout the 

 Blackfoot River during the early 1970 's. These hatchery fish 

 were recovered in the Hogum section during 1972 and 197 3, but 

 were absent from samples in all sections of reach 1 during 1988. 



Reach 2 : Lincoln to Nevada Creek 



(RM 110 to RM 67.8) 



Fish populations were sampled in two sections of reach 2 

 including: Poorman-Dalton (RM 108.0 to 109.1) and Canyon section 

 (RM 94.3 to 95.8). These sections were electrof ished in 1988 as 

 well as during the early 1970 's. Brown trout dominated the 

 fishery in this reach comprising 97% of the trout population. 



The highest density of brown trout in the Blackfoot River 

 was observed in the Poorman-Dalton section. Brown trout YOY 

 density estimated in 1988 was not significantly different from 

 previous estimates. The density of YOY ranged from 220 to 360 

 per 1,000 ft during the three population surveys (Figure 8). YOY 

 brown trout were found utilizing the downstream edges of beaver 

 dams, concentrations of rooted aquatic plants, and shallow debris 

 piles for day time summer cover. 



Densities of adult brown trout (age II and older) also were 

 not significantly different between sampling years, ranging from 

 44 to 61 per 1,000 ft (Figure 8). Yearling brown trout 

 densities, however, declined 53 percent from the 1971-1972 

 average of 73.5 per 1,000 ft to 39 per 1,000 ft in 1988. Similar 

 to YOY, yearling brown trout used brush associated with beaver 

 dams and shallow debris piles for summer day time cover. 



Brown trout redd counts in the Poorman-Dalton section were 

 50% higher during the fall of 1988 compared to counts during 1971 

 and 1972 (Figure 9) . The increase in the number of redds 

 observed in 1988 was probably related to relatively low flow 

 conditions restricting upstream movement of spawners, rather than 

 being a result of increased numbers of spawning fish. 



Densities of adult brown trout were significantly lower in 

 the Canyon section (15/1,000 ft) compared to the Poorman-Dalton 

 section (44/1,000 ft) during 1988 (Figures 8 and 9). Decreased 

 densities of adult trout in the Canyon section may be related to 

 relatively low numbers of juvenile trout observed in this 

 section. 



17 



