Researchers from Simon Fraser University analyzed 100-year-old salmon shells to assess the health of wild salmon populations.
The diversity and population of wild salmon in northern BC has decreased by nearly 70 percent over the past century, according to a new study from Simon Fraser University.
Researchers who rely on 100-year-old salmon shells report that recent numbers of adult wild salmon returning to Skina River are 70 percent less than they were 100 years ago. Likewise, the diversity of wild salmon in the Sakina watershed has decreased by 70 percent over the past century.
The research by Simon Fraser University (SFU) and Canadian Fisheries and Oceans was published today in Journal of Applied Ecology.
The research team applied modern genetic tools to salmon scales collected from commercial fisheries during 1913-1947 to reconstruct historical abundance and population diversity for comparison with modern information.
The analysis revealed that Canada’s second largest salmon watershed – the Skeena River – once hosted a variety of sockeye salmon consisting of many groups that fluctuated from year to year, and yet remained relatively stable overall.However, Skeena’s portfolio has been eroded. sockeye so much over the past century that it is now under the control of a single population mainly supported by the artificial production of hatcheries.
“Our study provides a rare example of how biodiversity within species has been eroded over the past century from human influence,” says Michael Price, a PhD candidate and lead author at SFU. “The loss of abundance and diversity of wild populations has impaired the adaptive ability of salmon to survive and thrive in an increasingly changing environment affected by climate change.”
The diversity of the life cycle has also changed: residents migrate from fresh water at a young age, and spend more time in the ocean.
“Rebuilding a variety of bountiful wild populations – that is, maintaining functional portfolios – should help ensure that watersheds important to salmon such as Skeena are robust for global change,” says John Reynolds, co-author, SFU professor, and head of leadership, Tom Buell BC. “In aquatic conservation.
This research can help assess the situation and rebuild plan discussions of threatened salmon populations by broadening our understanding of historical diversity and production potential.