Assessing bull trout movement ecology using acoustic telemetry and standardized watershed assessments to identify biologically important habitat for spawning, rearing and overwintering

This project will determine the spatial scales of reproductive and movement behavior of bull trout (Salvelinus confluentus) in the Eastern Slopes of Alberta. We aim to identify their spawning and rearing habitat, and their connectivity, using machine learning on existing data and telemetry techniques. Our goal is to provide improved information on bull trout ecology and biologically important habitat for provincial and federal status assessment, delineation of critical habitat, and recovery initiatives. These data will provide Alberta Environment and Protected Area, Fisheries and Oceans Canada, and others, the ability to make management and recovery decisions with the best available information. Although the primary focus of this proposal is bull trout, we will develop an assessment template that can also be applied to other stream spawning fish in Alberta.

We selected the Highwood River watershed as our focal system because it has no large dams, allowing bull trout to complete resident or fluvial (i.e. migrations from tributaries to mainstems) life histories. These two life histories would have been common in nearly all watersheds throughout their USA and Canadian distribution prior to the creation of dams and weirs in much of their southern distribution. We will pull together all existing data on juvenile locations from electrofishing surveys, and spawning locations from redd data, as well as conduct surveys to fill in data gaps in summer 2026. We will then correlate these data with environmental variables such as river temperature, river discharge, and riparian habitat characteristics. Using machine learning techniques on these correlations, we will locate areas of similar environmental conditions in the wider Highwood River watershed that could support juvenile and/or redds. We will visit these sites in 2027 to validate the machine learning model.

In addition, we will be using novel acoustic telemetry techniques to track the movement timings of adult bull trout. These techniques will allow us to monitor real-time movements throughout the watershed, and provide information on spawning locations, spawning behaviours and the environmental drivers of movement. In addition to spawning-related movements, the telemetry data will also enable us to assess the effects of natural waterfalls and stream crossings like culverts on movement, to estimate the connectivity of habitats in the Highwood River watershed. These data will also provide a detailed example of adult bull trout seasonal movement ecology, which can aid in updating the timing of regulations and policies surrounding important ecological events, particularly spawning.  

This is a collaborative project supported by Alberta’s Office of the Chief Scientist, Natural Sciences Engineering Research Council of Canada, Forest Resource Improvement Association of Alberta, Alberta Conservation Association, Ocean Tracking Network, Alberta Environment and Parks, University of Calgary, and Fisheries and Oceans Canada.