To evaluate the potential for reintroducing anadromous sockeye salmon into the Alouette Reservoir, studies are underway to monitor adult sockeye returns to the ALLCO Fish Fence. Now in its fourteenth year, this research tracks sockeye migration patterns and success rates. The initiative began with BC Hydro’s Water Use Plan, which provided spring surface releases from the Alouette Dam from 2007 to 2020, allowing kokanee/sockeye smolts to migrate to the ocean. The first adult sockeye returned to the Alouette Watershed in 2007 following these releases.
Since 2008, the Alouette River Management Society and Fraser Regional Correctional Centre have managed the Alouette Sockeye Adult Enumeration Monitoring Program under BC Hydro’s Alouette Water Use Plan (AWUP). This program began as a seven-year study to determine if Alouette Lake Reservoir kokanee/sockeye smolts from Alouette Lake could adapt to an oceanic life and return as spawning adults. Researchers aimed to assess migration success, the timing and genetics of returning sockeye (Oncorhynchus nerka)., and ocean survival rates. Tissue samples confirmed stock origin, while returning sockeye were counted, aged, and released into Alouette Lake.
Image 1. First Sockeye return in 2007, after 50+ years.
Image 2. Greta (Executive Director) and Sophie (Communications & Engagement Manager) supporting with Sockeye Sampling.
Adaptation is considered successful when sockeye return from the ocean environment to spawn in Alouette Lake. Additionally, the original monitoring program sought to establish the timing and genetic structure of the returning sockeye run and to assess whether ocean survival rates of returning re-anadromized kokanee were comparable to that of sockeye stocks found elsewhere.
Tissue samples were also collected from all sockeye in order to ensure that returning adults were Alouette stock and not strays from other nearby coastal systems. The viability and authenticity of kokanee smolt “re-anadromization” is dependent on the stocks ability to adapt to salt water conditions, to adopt behavioural strategies to compete and avoid predation in an ocean environment, and to recognize and return to their native lake/stream system to spawn. Through the Alouette Adult Sockeye Enumeration program, sockeye returning to the Alouette River are collected, counted, aged, genetically tested and released into Alouette Lake.
Image 3. Photo of the Trap at the ALLCO Hatchery
Image 3. Photo of the Fish Fence at the ALLCO Hatchery
Image 3. Photo of the Fish Trailer used to transport the Sockeye above the Alouette Dam
Image 3. Photo of the Sockeye Salmon being put into the Tank
The Alouette River Sockeye Reanadromization Project is developing a proposal for BC Hydro’s Board to support fish passage over the Alouette Dam, aiming to restore access to historic spawning grounds for sockeye and other species blocked since 1929. Sockeye were thought lost from the system until 2005, when some kokanee accidentally migrated downstream and returned as sockeye. This collaborative restoration initiative includes ARMS, BC Hydro, Fisheries and Oceans Canada, local First Nations including Katzie First Nation, Ministry of Environment, and LGL ltd., which provides critical funding for feasibility studies on fish passage.
This information and the work of the Alouette River Sockeye Reanadromization Project committee, is building towards a business case to present to BC Hydro’s Board of Directors to get fish passage over the dam for sockeye salmon and other species that have been excluded from their traditional spawning grounds in the upper Alouette Watershed since 1929. Sockeye salmon were extirpated from the Alouette system for close to eighty years when in 2005, with an accidental release of water through the Alouette spillway, some resident kokanee swam out and two years later came back as sockeye salmon.
The adult Sockeye enumeration program is part of a larger body of work, the “Alouette Watershed Sockeye-Fish Passage Feasibility Project” which is funded by the Fish and Wildlife Compensation Program (FWCP). The FWCP is a partnership between BC Hydro, the Province of B.C., Fisheries and Oceans Canada, First Nations, and public stakeholders to conserve and enhance fish and wildlife in watersheds impacted by BC Hydro dams.
The Alouette River Management Society gratefully acknowledges the financial support of the Fish and Wildlife Compensation Program for its contribution to the “Alouette Watershed Sockeye-Fish Passage Feasibility-Year 4” project.
