isoiet populations. In 2002 and 2003, the Blackfoot Cooperators continued to develop or 

 implement projects on 13 WSCT-bearing streams (Ashby Creek, Clearwater River, Cottonwood 

 Creek, Elk Creek, McCabe Creek, Nevada Creek, Nevada Spring Creek, North Fork Blackfoot, 

 Rock Creek, Pearson Creek, Poorman Creek, Wasson Creek and Wales Creeks) and monitored 

 WSCT populations on 17 project streams (Results Part III). We identified limiting factors for 

 WSCT on Wasson Creek, Little Fish Creek, Cottonwood Creek and an unnamed spring creek 

 tributary to Wales Creek. We also identified several diversion ditches as being detrimental to 

 WSCT populations by 1) bringing unwanted fish to areas of pure WSCT within the Nevada 

 Creek watershed, 2) entraining WSCT from the lower Clearwater River to a large canal, and 3) 

 entraining wild WSCT from Snowbank Creek to a put-and-take fishery at Snowbank Lake. 



In response to harvest restrictions and tributary restoration, densities of WSCT have been 

 increasing in the lower Blackfoot River (Johnsrud and Scotty Brown Bridge sections) since 1990 

 (Results Part II). In 2002, WSCT estimates (>6.0") ranged from a low of -0.5 fish/1000' below 

 Nevada Creek (Wales Creek Section) to -15-20 fish/1000' at monitoring stations of the lower 

 river (Johnsrud and Scotty Brown Bridge sections). Low densities in the Wales Creek section 

 reflect impaired water quality and degraded tributaries in this section of river. 



In response to WSCT introgression risk, we converted a private pond and public lake 

 plants to a genetically compatible brood source of WSCT in WSCT habitat. Conversions 

 involved: 1 ) rainbow trout to sterile rainbow in private ponds of the Union Creek drainage, and 

 2) rainbow trout to WSCT in Nevada Reservoir and Coopers Lake. Despite these changes, 

 challenges to pond and lake management in WSCT habitat persist. "Lifetime private pond permits 

 for non-compatible species in WSCT habitat allow for example rainbow trout plants. In 

 wilderness areas, established lake populations of rainbow and Yellowstone cutthroat trout 

 coincide with the hybridization of WSCT. 



Increasing levels of angler pressure is a growing concern for WSCT, particularly 

 in the middle Blackfoot River where angling pressure has increased 611% since 1989 

 (Results Part IV). High angler pressure, compounded by high WSCT catchability in the 

 Blackfoot River (Schmetterling and Bohnemann 2001) increases risk of disproportionate 

 angling mortality for WSCT compared with other species. Hooking mortality generally 

 ranges from 4.8% for barbed flies to 33.5% for barbed bait used as terminal gear (Taylor 

 and White 1992). Based on estimates of angler pressure (2001) and WSCT densities 

 (2002), we estimate ~ 6 anglers (per year) for every one WSCT (>6.0") present in the 

 middle Blackfoot River (Angler Pressure Estimates 2001 - Results Part IV, Appendix C). 

 Recent creel surveys showed WSCT comprised 34% of the angler catch (Schmetterling 

 and Bohnemann 2001), while population estimates show the relative abundance of 

 WSCT ranges from approximately 4 - 22% of the total Blackfoot River trout population 

 (Appendix C). Telemetry studies and warden patrols have also revealed continued 

 illegal harvest of WSCT in the Lincoln area (Results Part IV). 



Whirling disease is generally found at elevations below most known WSCT 

 spawning and rearing sites with some exceptions, including Chamberlain Creek, an 

 important fluvial WSCT spawning stream in lower Blackfoot Watershed (Schmetterling 

 2001). Recent declines in WSCT in Chamberlain Creek coincide with the period of 

 whirling disease escalation and the recent drought. It is not possible to separate the 

 effects of these two threats. 



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