lacking cover while in tributaries, increasing their vulnerability to predation during the 

 current drought. 



Restoration and management implications 



This study underscores the importance of two spawning streams in the upper 

 Blackfoot basin, while expanding the known geographic scale of both North Fork and 

 Copper Creek bull trout stocks regarding the mainstem Blackfoot River. Based on this 

 and previous telemetry studies (Swanberg 1997, Schmetterling 2003), bull trout that 

 spawning in the North Fork occupy the Blackfoot River from its mouth to Lincoln and 

 downstream in the Clark Fork >30 miles. The known range of Copper Creek spawning 

 stock has greatly expanded, extending from spawning sites, downriver -65 rm, to near the 

 confluence of the North Fork. These broad areas of use underscore a need to manage and 

 recovery bull trout on a regional scale. 



Although many human-related factors cumulatively influence the strength of both 

 local populations over broad areas, many habitat problems are being corrected in the 

 lower Blackfoot Watershed, and have been identified in the upper Blackfoot Watershed. 

 Within the North Fork, irrigation ditch screening, tributary restoration and instream flow 

 enhancement in critical migration corridors are at various stages of implementation. 

 Improvements like these contribute to increases in bull trout redd counts and increased 

 use of juvenile bull trout in restored streams (Pierce et al. 2002, this report Results Part 

 rV). However, loss of flows (irrigation and natural) during the North Fork bull trout out- 

 migration time-period continue to periodically isolate adult bull trout in intermittent 

 reaches during low flow years (Pierce et al. 2002). Instream flow enhancement through 

 improved irrigation efficiency has potential to correct this "bottleneck" to out-migrant 

 North Fork bull trout. At this point, there are no significant recovery efforts directed 

 towards anthropogenic problems influencing the Copper Creek bull trout population. 

 However, potential restoration opportunities have been identified throughout tributary 

 and mainstem reaches (Pierce et al. 2002, 2001; this report, Results Part FV), and extend 

 from spawning sites (Snowbank Creek and the Talon-Snowbank bum area) down river to 

 the area of Nevada Creek. 



WSCT movements and habitat use 



Compared with fluvial WSCT telemetry study in the lower Blackfoot Watershed, 

 our study was undertaken higher in the drainage (above the North Fork), above the range 

 of rainbow trout reproduction and the general distribution of rainbow trout. This area is 

 identified as a region of high genetic WSCT integrity with most sampled streams 

 supporting genetically unaltered populations of WSCT (Pierce et al. 2000; Shepard et al. 

 2003, this report). Densities of fluvial WSCT are low and range from ~9 fish/1000 

 (>6.0") in the upper reach (above Arrastra Creek) to -0.5 fish/1000' in the lower reach 

 below Nevada Creek (Pierce et al. 2000; this report Results Part II). 



As expected, our study confirmed many aspects of WSCT movement and 

 spawning behavior similar to the lower Blackfoot drainage including migration timing 

 and tributary use (Schmetterling 2001). However, we also found considerable differences 

 in the movements and behavior of WSCT in the upper river (above the North Fork) 

 compared with the lower river (below the North Fork). Similar to bull trout, these 



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