North Saskatchewan River Drainage, Fish Sustainability Index Data Gaps Project, 2017
Chad Judd, Mike Rodtka, and Zachary Spence
We sampled 52 sites located throughout six priority HUC 10 watersheds within the Blackstone River and Brazeau River HUC 8 watersheds using backpack and tote-barge electrofishing gear. A total of 26 sites were located within West Fraser Mills Ltd.’s forest management area. Both immature and non-immature bull trout were detected in all six HUC 10 watersheds. The Thistle Creek watershed had the highest relative abundance of bull trout indicating its importance for spawning and rearing habitat. Mountain whitefish were observed in four of the six HUC 10 watersheds. Immature mountain whitefish had the highest relative abundance in the Upper Blackstone River watershed. Non-native brook trout and cutthroat trout were found in all of the HUC 10 watersheds, except Thistle Creek and Devil Forks, respectively.
Stream temperature measurements indicate that summer temperatures were highly suitable for bull trout in the Thistle Creek and Upper Blackstone River watersheds. All of the watersheds, except Devil Forks and Wapiabi Creek, had cobble as the dominant substrate, a habitat quality preferred by immature bull trout (ASRD and ACA 2009).
Our study provides current information on stream habitats, and the abundance and distribution of FSI priority species within the Blackstone River, its tributaries and tributaries of the Brazeau River. This information is useful to land managers when attempting to balance the diverse values of the landbase upon which they operate and critical for the conservation of native fish species particularly sensitive to habitat degradation including bull trout.