Monitoring Temperatures to Ensure Stream Health-Many populations of native trout along the eastern slopes of the Canadian Rocky Mountains have declined in range and numbers. Native fish face a variety of threats including habitat loss and fragmentation, overexploitation, changes to water quality and quantity, temperature issues, and impacts from non-native species.
A relatively new threat to Alberta’s fisheries is whirling disease. Impacts of whirling disease on fish have been varied in other regions. In some cases, whirling disease has caused severe declines in trout populations while in other cases, whirling disease has been present for several years without any indication of population-level effects.
In 2016 whirling disease was confirmed in Alberta and since then has been confirmed in four major watersheds in Alberta. To manage and mitigate whirling disease, we need to understand the interactions between the biology of the disease-causing parasite and the environmental conditions.
Whirling disease is caused by a microscopic parasite, Myxobolus cerebralis, and affects salmonid fishes including trout and whitefish by deforming and killing juveniles. The parasite requires two hosts: tubifex worms, which are found in many waterbodies, and salmonid fish. Myxospores are released from tubifex worms when the water temperature is between 10 °C and 15 °C. Knowledge of the temperature profiles of streams along the eastern slopes where whirling disease could be a threat to fish populations is a piece of the puzzle we are missing.
In partnership with Alberta Environment and Parks (AEP), Trout Unlimited Canada (TUC) members in Alberta are assisting with the deployment of over 600 temperature data loggers this summer to monitor stream and river temperature across the eastern slopes. The data collected during this project will help managers assess risk zones based on temperature profiles where M. cerebralis and whirling disease is most likely to be a concern to fish populations. This will also build a powerful network of stream temperature monitoring data that can be used for a variety of other science and conservation initiatives.
On July 5 and 6, 2018 TUC volunteers joined AEP Biologist Marie Veillard to learn how to select sites and deploy temperature loggers.