Physiological and behavioural performance metrics of Athabasca rainbow trout (Oncorhynchus mykiss) across varying thermal regimes in the Athabasca river watershed ...

• Main Author: Hnytka, Sarah
• Format: Text
• Language: English
• Published: University of British Columbia 2023
• Subjects: Athabasca River
• Online Access: https://dx.doi.org/10.14288/1.0438303; https://doi.library.ubc.ca/10.14288/1.0438303

Stream temperature is a key driver of physiological function in ectothermic fish, and fish have clear upper and lower limits of thermal habitat, bounding a range of optimal conditions. Predicted stream temperature increases from climate change are a major threat to Athabasca Rainbow Trout (Oncorhynchus mykiss; ARBT) which are listed as Endangered under Schedule 1 of Canada’s Species at Risk Act. Knowledge gaps concerning temperature preferences, thermal limits, and habitat suitability need to be addressed to effectively manage and recover this endemic ecotype. In this study, ARBT were collected from July – August in 2021 and 2022 from three streams in the McLeod River watershed, Alberta, Canada, representing a gradient of thermal regimes ranging from cold to warm. Fish were tested for four physiological metrics: agitation temperature (Tag), critical thermal maxima (CTmax), avoidance temperature (Tavoid) and preferred temperature (Tpref) using a portable streamside laboratory. Both Tag and Tavoid metrics are ...