Why Logging Water Temperatures Matters for Alberta’s Native Trout

by Dr. Benjamin Kissinger, Water & Fish Program Lead, fRI Research

Temperature loggers are often attached to pieces of rebar, which must be hammered into the streambed.

Though almost all fisheries biologists and researchers become interested in their work because they get to see and handle fish in beautiful environments, with time, many come to realize that studying things other than fish is essential to properly understand why fish exist here and not there. One key relationship that shapes nearly all fish distributions is that with water temperature.

For species that have evolved to exist in cold water, access to this habitat is shrinking through loss of riparian vegetation, changes to hydrology, and climate change. With the lack of snow fall this past year in Alberta, and warm temperatures, we are off to a poor start for these cold-water species, highlighting the challenges that may become more common moving into the future. For fish that exist in rivers, access to cold water becomes challenging because it typically warms as a fish moves down stream, creating an invisible thermal barrier to fish movement. The upstream end of their distribution is typically colder, but physical barriers (shallow water or waterfalls) restrict upstream movement and result in a limited area that a cold-water fish can exist in during peak summer temperatures. For these reasons, understanding cold-water habitats availability and extent is important for identifying and preserving this habitat for cold water fish species.

Staff take pictures pointing at the logger in-stream, to make logger retrieval easier.

To better understand where this cold-water habitat exists and what areas are at greatest risk to future threats, models are needed to allow comparisons throughout Albertas East Slopes. This is important as three cold water species (Bull Trout, Westslope Cutthroat Trout, and Athabasca Rainbow Trout) are federally listed under the Species at Risk Act. Results from these models will assist resource managers in selecting areas for recovery actions and protection.

Figure 1. Water temperature model standard error by HUC 10 along Alberta’s East Slopes as of spring 2023. Areas that are black were not modelled — produced by MacHydro.

Figure 2. Example model of August average temperature for the Beaverlodge and Redwillow River drainage produced by MacHydro.

fRI Research Water and Fish Program has taken on the lead role in collating existing water temperature data for the province of Alberta and collecting new data with the goal of producing predictive water temperature models for Alberta’s East Slopes. Funding for this project has been provided in part by Fisheries and Oceans Canada (DFO) through the Habitat Stewardship Program for Aquatic Species at Risk and the Forest Resource Improvement Association of Alberta (sponsored by West Fraser, Canfor, and Weyerhaeuser).

To collect this data, we deploy small temperature loggers (Figure 3) that take continuous measurements hourly throughout the summer. We focus our data collection on the month of August since it represents the warmest month of the year with lowest flows (Figure 2).

Figure 3. Temperature logger, about the size of a toonie.

This work is highly collaborative and involves data collection and submission by numerous organizations. In addition, MacDonald Hydrology Consultants Ltd. (MacHydro) is taking the lead on the model creation and has developed a web-based platform for creating their models and outputs (Figure 1 and 2) that when finished will be publicly accessible. MacHydro and fRI Research worked together in spring 2023 to identify data gaps in the model as depicted in Figure 1. Based on this initial analysis, nearly all watersheds could benefit from additional sampling (Figure 1).

Under the guidance of fRI Research, 376 temperature loggers were deployed and collected throughout Alberta’s East Slopes in 2023.

We also noted that mainstem rivers and areas in the National Parks were lacking the most data as of spring, 2023 (Figure 1). Under the guidance of fRI Research, 376 temperature loggers were deployed and collected throughout Alberta’s East Slopes this past year, focusing on road accessible sites outside of National Parks (Figure 4). To complete this work, Trout Unlimited Canada, Poseidon Environmental Ltd., and Aseniwuche Environmental Corporation Ltd. conducted the deployment and recovery of temperature loggers (Figure 4). An additional 302 locations were also found and incorporated into the current dataset from various organizations in 2023 (Figure 4). We also anticipate data from ~300 locations that were deployed in the National Parks and will be incorporated into this dataset, resulting in ~1000 new locations added in 2023. Through the winter of 2023/2024, fRI Research is QA/QCing the data and actively working with MacHydro and partners to combine new data (Figure 4) and existing data (Figure 1) into an updated model to aid in site selection for summer 2024. In summer of 2024, we are planning to continue expanding this sampling to fill data gaps and improve model fit.

Figure 4. New water temperature data locations added to the model in 2023. TUC = Trout Unlimited Canada, AEPA = Alberta Environment and Protected Areas, GWAS = Ghost Watershed Alliance Society, DFO = Fisheries and Oceans Canada, Alberta Rivers = www.rivers.alberta.ca, AEC = Aseniwuche Environmental Corporation, ACA = Alberta Conservation Association. * indicates partners that were subcontracted under grants through fRI Research in summer 2023.

If you are interested in supporting this project or have historic temperature data, please reach out to Ben Kissinger at bkissinger@friresearch.ca.