North Saskatchewan River Drainage, Fish Sustainability Index Data Gaps Project, 2016

Author(s)

Chad Judd, Mike Rodtka and Andrew Clough

Summary

Fishery inventories provide resource managers with information on fish abundance, species
distribution and fish habitat. This information is a key component of responsible land-use
planning. Alberta Environment and Park’s Fish Sustainability Index (FSI), a standardized process
of assessment, provides the framework within which future fishery inventories must occur for
greatest relevance to government managers and planners. Bull trout (Salvelinus confluentus) are
particularly sensitive to habitat change and classed as Threatened in Alberta
(Saskatchewan – Nelson rivers populations). Our objective was to describe bull trout, mountain
whitefish (Prosopium williamsoni) and burbot (Lota lota) distribution and abundance in the
headwaters of the North Saskatchewan River watershed to address FSI data deficiencies. Focal
areas for inventory in 2016 were identified in consultation with project partners and included Elk
River, Rifle Creek and Crow Creek.


From June 15 to August 17, we visited 41 sites randomly distributed throughout the five
hierarchical unit code (HUC 10) watersheds identified as priority areas. We sampled 40 sites
using backpack and tote-barge electrofishing gear. We captured 38 bull trout, 27 mountain
whitefish and 56 burbot. Bull trout were detected at 10 sites in both the Upper Elk River HUC
and Middle Elk River HUC. Immature bull trout were predominantly found at one site on a
tributary to the Elk River, indicating the importance of this stream as spawning and rearing
habitat for bull trout. Mountain whitefish and burbot were the only other sport fish caught in
these HUC 10s. White sucker (Catostomus commersonii) dominated our catch (n = 1,296), was
detected in every HUC, and was the most widely distributed species overall (detected at 30 sites).
We monitored stream temperature (every hour) at eight stations in these HUC 10s to assess
thermal suitability for bull trout. Stream temperature monitoring of the Elk River area indicated
the headwaters provided suitable thermal habitat for bull trout in the summer of 2016. Our study
provides current information on stream habitats and on the abundance and distribution of FSI
priority species within the Elk River and surrounding tributaries. This information is useful to
land managers when attempting to balance the diverse values of the land base upon which they
operate and critical for the conservation of native fish species particularly sensitive to habitat
degradation, such as bull trout.

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