Tagging Fraser Chinook to identify salmon migration disruptions.
Fraser River Chinook salmon have experienced declines for many years. As a result, at least 15 of the 17 wild populations of Fraser Chinook are considered at-risk. Still, their migration has not been well-studied because their return to the Lower Fraser occurs during the spring thaw, or freshet, a challenging time to study fish.
A partnership between the Pacific Salmon Foundation (PSF), Matsqui First Nation, Yale First Nation, and Fisheries and Oceans Canada (DFO) is tagging adult Chinook salmon and tracking their migration to identify potential locations where the fish face impediments as they journey to their spawning grounds.
High flow conditions in the Fraser, expected to become more common as climate change increases extreme weather events and alters snowmelt timing, pose migration difficulties for salmon. When flows are high, salmon require more time and energy to reach their spawning grounds, influencing their survival. For example, high flows in 2020 led to Fraser salmon not showing up to Big Bar, a section of the Fraser 64 kilometres north of Lillooet, for the first four to six weeks of their migration, indicating that flow conditions in the lower parts of the Fraser Canyon were holding them up.
“Given the increasing evidence of climate effects across B.C., we need to study salmon behaviours in the migration corridors of the Fraser,” says Jason Hwang, PSF’s VP of Salmon. “Intending to assess potential migration disruptions, we hope to identify areas where it may be possible to improve migration conditions, making the journey easier for salmon and improving survival outcomes.”
Fish wheels, rotating, water-powered devices used to capture fish, were installed at three locations in the Lower Fraser to enable the fish to be caught, tagged with radio tags, and released to be tracked.
In the first year of the project, 98 adult Chinook were tagged. The second year is currently underway, with tagging ongoing for early-run populations and expected to continue throughout the summer as high flows and debris volumes subside, and additional populations return.
Fisheries and Oceans Canada (DFO) is also tagging and tracking salmon in the Fraser to assess sockeye migration. Combined, PSF and DFO’s tagging projects provide in-depth tracking coverage for salmon in the key migration corridors in the Fraser.
Special thanks to Hon. Josie Osborne, Minister of Land, Water and Resource Stewardship and Bob D’Eith, MLA of Maple Ridge-Mission for joining PSF on a tour of the project in July 2022.
The B.C. Salmon Restoration and Innovation Fund provided support for this project.