Studying Arctic Grayling and Bull Trout interactions in Williston Reservoir

Project Year: 2018-2019

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Arctic Grayling Photo Credit: Steve Rooke

Project Lead

University of Northern British Columbia (UNBC)


Peace Region


Project Type

Research & Information Acquisition

FWCP Contribution


Action Plan Alignment

Streams Action Plan

Project ID


Spatial ecology of Arctic Grayling in the Parsnip core area

This project will investigate the spatial ecology of juvenile and adult Arctic Grayling and their interactions with Bull Trout in the Parsnip River and its tributaries. The objectives will be addressed using a combination of approaches including acoustic telemetry, capture-recapture, temperature data logging, stable isotope analysis and spatial modelling. The findings of the project will address a number of moderate and high immediacy data gaps related to: 1) the spatial ecology (migration, distribution, and habitat use) of Arctic Grayling that were identified for the Parsnip River core area; and 2) potential interactions with Bull Trout, which may be limiting the growth of Arctic Grayling populations throughout the Williston Reservoir watershed.

Update: 63 fish tagged in Arctic Grayling study

Sixty-three fish tagged in Year 1 In Year 1 (2018), 63 fish (50 Arctic Grayling and 13 Bull Trout) were tagged (acoustic transmitters, and/or PIT [Passive Integrated Transponder] and anchor tags), mostly in the Anzac River. Fifty-four acoustic receivers were deployed in the Parsnip River Watershed and one in the lower Pack River. Data loggers were deployed to monitor air and water temperature throughout the Parsnip Watershed. A total of 89 samples (adipose fin, muscle, invertebrates, plants, particulate organic matter) were obtained for stable isotope analysis of carbon and nitrogen. The analysis is currently being conducted in the Environmental Isotope Laboratory, University of Waterloo.


Final report: executive summary

Flooding of the Upper Peace after construction of the W.A.C. Bennett Dam in 1967 resulted in a considerable loss of riverine habitat to Arctic grayling. The decrease in available habitat, alteration of natural hydrology and evidence of drastic reductions in population size caused great concern for the sustainability of Arctic grayling (Thymallus arcticus) populations in the Williston Reservoir Watershed. The recent review by Stamford et al. (2017) and monitoring framework by Hagen and Stamford (2017) highlighted a number of critical information gaps related to the spatial ecology of Arctic grayling such as: (1) the unknown distribution of Arctic grayling within the streams of the different core areas (sensu Stamford et al. 2017); and (2) the lack of understanding of Arctic grayling migrations. Furthermore, its unknown whether populations of bull trout (Salvelinus confluentus) are limiting the abundance of Arctic grayling and their spatial distribution.


Click the provincial database link below to read the full final report for this project.

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