Thermal Refugia Study

The primary goal of this study was to identify and map areas in selected streams on the east coast of Vancouver Island where water temperatures are primarily affected by groundwater input. Groundwater serves as a source of cold water during warm summer months, providing thermal refugia for Pacific salmonids and other cold-blooded fish. These thermal refugia will be especially important in minimizing the adverse effects of climate change. Knowing the locations of these thermal refugia will benefit wild Pacific salmon stocks by allowing us to prioritize locations for stream restoration and protection. A secondary goal is to advance the methodologies used to complete the refugia investigations.

Work completed on this multi-year study include the use of arrays of Tidbit temperature loggers and “thermal maps” created using drones with Forward Looking Infrared capabilities to identify thermal refugia in selected watercourses. The project is ongoing and is supported through funding provided by the Habitat Conservation Trust Fund and Pacific Salmon Foundation.