Reconnecting Fluvial Westslope in Skalkaho Creek Is this working and how do we tell?
Skalkaho Creek
Major Ditches and Dams
Skalkaho Creek Republican Ditch Hedge Ditch
2001 Fluvial cutthroat pass over all dams and reach Bitterroot National Forest Ditches entrain large numbers of cutthroat, bull and brown trout
Skalkaho Creek Fish Passage and Protection Project Identifies locations of fish entrainment Recommends various strategies
Decision Attempt to aid juvenile fish and adult spawners downstream to Bitterroot River Do nothing at this time to help fluvial fish move upstream
$900,
Pros and Cons for Success Pros Migratory Cutthroat still connected somewhat Many downstream migrating juveniles in upper creek Adult post spawners lost into ditches Small number of cutthroat and bull trout in lower creek. Cons Fish in ditches (bull trout) may be residents (L. Nelson) Worried about all the brown trout in lower creek Dewatered reach may be problematic River Temperatures and species may be problematic
Studies pertaining to Skalkaho projects 2005 – Steve Gale (Prior to Siphons) – Skalkaho system selecting for residents – Screens returning thousands of CT to Skalkaho – Post spawning adult cutthroat being entrained – Screening may help maintain fluvial fish – Worried about brown trout 2007 – Ryan Harnisch – Screens are working well – Siphons should stop entrainment of post spawn adults – Monitor it! – Worried about brown trout
Monitoring Reach
Restoration Monitoring 2 Single Pass sites in Dewatered Reach Population Estimates in Creek Downstream migration -- Screwtrap Bitterroot River
Monitoring Reach
Skalkaho Creek 5.8 Brown trout > 6”Westslope Cutthroat > 6” 1996
Monitoring Reach
Dewatered Reach Single Pass Skalkaho Creek 1.2 Single Pass
April October
Westslope Cutthroat > 10” Hamilton Section and 5 recapture estimates
Restoration Scorecard Single Pass in Dewatered Reach Population Estimates in Creek Downstream migration Bitterroot River
Conclusions (stay tuned) Screens and Siphons are working as planned Monitoring data for fish is mixed and, in general, disappointing Documenting change in a relatively small population of migratory cutthroat in a large drainage is not easy using routine methods Still worried about brown trout Is the fish community and habitat in the river also a controlling factor?