Modelling Thermal Regimes of the Upper Peace River Basin
This project will focus on the cumulative effects of land use, climate change, and water flow regulation on river water temperatures in the upper Peace River Basin.
Using a three-scale temperature monitoring and modelling approach, the project’s primary goal will be to quantify and predict the spatial distribution of thermal habitat for cold-water fish. A secondary objective is to construct a network of water temperature loggers in the Williston Watershed, from headwater streams down to the Peace River.
The project outcomes will provide valuable information for the management of cold-water-adapted fish.
Update: Temperature loggers monitor cold-water fish habitat
In 2023, the focus was an expanding the array of temperature loggers to include the Nation, Omineca, and Osilinka River watersheds. By summer 2023, 111 temperature loggers were deployed and capturing important data about temperature and other watershed characteristics.
Five real-time hydrometric stations were also added to the Nation River, Parsnip River, and Pack River watersheds, for a total of 16 active stations.
Together, the new loggers and stations will provide important data for the management of cold-water adapted fish.
Executive Summary
Aquatic ecosystems have been identified as vulnerable to increased air temperatures due to their low thermal inertia and high temperature variability. The spatio-temporal availability of thermal habitats is one of the most important drivers of fish distribution and migrations in freshwater environments. The FWCP and the Environmental Stewardship Initiative between the Tsay Keh Dene Nation and the BC Government have a combined interest in assessing the potential effects of climate change and land cover change on fish populations and habitats and to prioritize conservation of species and habitats most vulnerable to impacts. This project aims to provide a monitoring framework under which the impacts of climate change and land cover on aquatic thermal habitat can be investigated, the extent of cold-water refugia can be identified and insight can be made into thermal habitat availability and its impact on the distribution and abundance of two focal priority species Bull Trout and Arctic Grayling within the Upper Peace River. This project aligns with the Rivers, Lakes and Reservoir FWCP priority action plan (PEA.RLR.204.RI.13), sub-objective 4 (maximize the population viability of Bull Trout) and secondary action plan (PEA.RLR.S01.RI.01), sub-objective 1 (maintain and/or increase the resilience of aquatic ecosystems to habitat disturbances, including climate change and other cumulative effects).
In 2023, the focus of equipment deployments was on expanding the existing array deployed in 2022 to include more watershed characteristics, and expanding the array into the Nation, Omineca and Osilinka River watersheds. These watersheds were selected because of their importance to First Nations and availability of historical data. In addition, they present a gradient of landscape disturbance which aids in study design and the investigation of impacts on thermal habitat. In total 111 loggers were active in the array in summer 2023. Thirty in Ingenika River, 31 in the Mesilinka River, 39 in the Parsnip River, 5 in the Nation and Osilinka River and 1 in the Omineca River. We added five new real-time hydrometric stations, in addition to the existing 11 deployed and surveyed in 2022, for a total of 16. The new stations were added in the Nation River watershed (Suschona Creek at FSR and Sylvester Creek at FSR), the Parsnip River watershed (Colbourne Creek at FSR and Crocker Creek at Crocker FSR), and the Pack River watershed (Crooked River at 200 Rd). Our hydrometric station data is currently available in real-time from the Northern BC Hydrology Research website (https://bcgov-env.shinyapps.io/nbchydro/) and will also be uploaded to the BC Government Aquarius hydrometric data portal following completion of quality assurance and quality checks (https://aqrt.nrs.gov.bc.ca/). Initial rating curves were estimated this year but require further discharge measurements from the 2024 season to confirm accuracy.
Water temperature data collected during the 2023 field season and from previously funded FWCP projects were selected and analyzed to investigate and compare reach-scale thermal habitat patterns for within Bull Trout spawning habitat and migration corridors. Thermal habitat summaries show a marked difference in exceedances of thermal thresholds in sites within migration corridors when compared to spawning habitat sites. In 2023, thermal sensitivity to air temperature increased compared to 2022 and mean variability was similar between habitat types except in the most extreme cases in Point Creek and Parsnip River. Except for Misinchinka River, Lay Creek and Point Creek, thermal sensitivity was in the high category at all sites in 2023. Interannual variations in thermal sensitivity was expected in migration corridor sites, however in the typically more stable high elevation Bull Trout spawning habitats, this variation and high thermal sensitivity was unexpected. This could be caused by the lower thermal inertia of small streams and shifting hydroclimatic conditions. We examined various basin scale modeling approaches and showed that models have different performance levels in simulating freshwater temperatures in river and reservoir. In particular, the Air2Stream model achieved better performance in simulations while requiring less data compared to statistical models, making it a better choice for modeling river systems. In contrast, statistical regression models were found to be more effective than Air2Water in capturing the daily variability in reservoir surface water temperature. We recommend using the Air2Stream model for river modeling due to its more reliable performance whereas in case of the reservoir modeling, both statistical models and hybrid models need to be tested to ensure the application of the most suitable modeling framework.
Click the link below to read the full final report for this project.