PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
Rainbow Trout (Oncorhynchus mykiss) is a species of salmonid that is characterized by a silver body covered in black spots with a pink horizontal band. In Canada, Rainbow Trout is native primarily to the western drainages of the continent. There are only three drainages east of the continental divide known to contain native populations of Rainbow Trout: Peace, Liard and Athabasca drainages, and Rainbow Trout (Athabasca River populations) (herein Athabasca Rainbow Trout) is the focus of this report. Athabasca Rainbow Trout are not considered a distinct subspecies, but qualify as a single designatable unit.
This fish is an obligate resident of clear, cold flowing water in the upper Athabasca River drainage of Alberta. Quantitative sampling over the last two decades demonstrates that the majority of sites are declining in abundance with an estimate of >90% decline over three generations (15 years). Threats are assessed as severe due to habitat degradation associated with resource extraction and agricultural practices. Additionally, ongoing climatic change and associated altered thermal regimes and hydrology, habitat fragmentation, introgression from non-native Rainbow Trout, and fishing threaten the species. Potential impact of invasive Brook Trout is a concern.
Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to "assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species".
COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (October, 2013 to September, 2014) from November 24 to November 29, 2013 and from April 27 to May 2, 2014. During the current reporting period, COSEWIC assessed the status or reviewed the classification of 56 wildlife species.
The wildlife species assessment results for the 2012-2013 reporting period include the following:
Special Concern: 20
Data Deficient: 0
Not at Risk: 1
Of the 56 wildlife species examined, COSEWIC reviewed the classification of 40 that had been previously assessed. The review of classification for 25 of those wildlife species resulted in a confirmation of the same status as the previous assessment.