Eastern Slopes Fisheries Inventory, 2018 – 2019
Author(s)
Chad Judd, Mike Rodtka, and Zachary Spence
Summary
Fishery inventories provide resource managers with information on fish species abundance, distribution, and habitat. This information is a key component of responsible land-use planning. Alberta Environment and Park’s Fish Sustainability Index (FSI) is a standardized process of assessment that provides the framework within which fishery inventories must occur for greatest relevance to government managers and planners. Our objective was to describe fish distribution, abundance, and habitat in the James River watershed of Alberta, with emphasis on bull trout (Salvelinus confluentus) in order to address data deficiencies for this FSI priority species. Bull trout are particularly sensitive to habitat change and are listed as Threatened in Alberta (Saskatchewan and Nelson rivers populations).
Priority areas for fishery inventories were identified in consultation with project partners and included the James River and its tributaries. From June 19 to June 28, 2018 and July 16 to August 13, 2019 we sampled fish at 50 sites randomly distributed throughout five watersheds classed as hydrologic unit code (HUC) 10: Willson Creek, Upper James River, Middle James River, South James River, and Lower James River. Sites were sampled using backpack and tote-barge electrofishing gear. In 2018 and 2019, we measured stream temperature (hourly) in the HUC 10 watersheds (except Willson Creek).
We captured 987 fish, including 90 bull trout ranging in size from 41 mm to 504 mm fork length. Bull trout were detected at eight sites in the Willson Creek HUC 10 watershed and at two sites in the Upper James River HUC 10 watershed; bull trout were not detected at any sites in the Middle, South or Lower James river HUC 10 watersheds. Ten sites (of the 50 sites sampled) across all watersheds had zero captures of any fish species. The Willson Creek HUC 10 watershed had the highest median relative abundance of bull trout at 2.1 (CL = 0.7 – 4.7) bull trout per 100 m. Highly suitable thermal habitat for bull trout existed in the Upper James watershed, as well as Teepee Pole Creek and Upper Stoney Creek (major tributaries in the James River watershed) in the summer months of 2019. Large gravel and cobble substrate were predominantly found throughout the Willson Creek and Upper James River HUC 10 watersheds, a habitat quality preferred by bull trout.
Our study provides current information on stream habitats, and the abundance and distribution of FSI priority species within the James River and its tributaries. This information helps land managers balance the diverse values of the land base upon which they operate, and is critical for the conservation of native fish species that are particularly sensitive to habitat degradation, including bull trout.