This and other assessment demonstrate that genetically pure fluvial WSCT utilize 

 significant portions of the upper Blackfoot watershed in the absence of hybridizing 

 species (Pierce et al. 2002, 2001, 2000, Shepard et al 2003, this report). Within this 

 setting, a primary conservation strategy identified in the upper Blackfoot Watershed 

 involves managing for metapopulation function and multiple life-history strategies 

 (Shepard et al. 2003). This conservation strategy involves protecting existing high quality 

 habitat, improving altered habitat, and maintaining or improving the connection between 

 occupied habitats. This strategy further involves 1) correcting road crossings to allow 

 passage, 2) sustaining recruitment of LWD to tributaries and the river, and 3) managing 

 lakes and private fishponds with appropriate species. We also identified poaching 

 problems in the Lincoln area and a need for additional enforcement (and education) at 

 public fishing access sites. 



Fluvial WSCT of the Blackfoot River rarely used tributaries between the North 

 Fork and Arrastra Creek. None used Nevada Creek, Youmame Creek and Frazier Creek, 

 despite WSCT in the headwaters of these streams. Tributary assessments report 

 degradation and fragmented habitats (and populations) in lower stream reaches of these 

 streams (Pierce et al. 2001). Only Wales Creek received limited spawning use by three 

 WSCT and of these, two did not survive due to speculated irrigation-induced low flows 

 during the spawning period. Wales Creek is the lowest-most spawning site identified in 

 this study. This spawning site overlaps with the upper range of the rainbow trout and 

 may be influenced by private fish-ponds containing rainbow trout, which drain in to lower 

 Wales Creek. A critical example of this influence is of the two WSCT showing 

 hybridization, both entered Wales Creek. For the lower reach as a whole, managing for 

 either resident or fluvial WSCT will require correcting extensive anthropogenic problems 

 resulting primarily from agricultiu"al practices. 



Arrastra Creek, the next upstream (identified) spawning stream (28.4 miles 

 upstream of Wales Creek) received the highest amount of spawning use of all streams; 

 however, all fish spawned downstream from a set of improperly placed culverts. During 

 the WSCT migration period, we measured velocities at these culverts at >7 ft/sec, well 

 above recommended velocities for fish passage through culverts (Evans 1974). 



FWP studies identify restoration potential on many Blackfoot tributaries in the 

 upper reach between Arrastra Creek and Lincoln (Pierce et al 2000). Tributaries in this 

 area are less impaired, and problems in the upper reach are more localized and restoration 

 can be completed with less effort and at less expense than tributaries entering the lower 

 reach. Interestingly, tributaries to the Blackfoot River upstream of Lincoln provide a 

 substantial amount of the spawning for fluvial westslope cutthroat and bull trout that 

 summer and winter in the Blackfoot River between Lincoln and the North Fork, despite 

 intermittent channels and long distances between tributary spawning sites and nodal 

 habitats. Protection of these areas should be considered within the context of downriver 

 recruitment and migration corridors maintained. 



Conclusions 



Diversity of life history traits is common in native inland salmonids (Behnke 

 1992). In the Blackfoot Watershed, local diversity partially results from selective 

 pressures in a post-glacial landscape of regional geoclimatic variability. Dispersal and 



77 



