Log-boom operations in the Cowichan-Koksilah estuary are having a devastating impact on wild Pacific salmon populations, according to a report by Cowichan Tribes, BC Conservation Foundation, and the Pacific Salmon Foundation.
The report, part of a joint eight-year study, emphasizes the need for best practices to be implemented to support the survival and recovery of Chinook salmon and estuary ecosystems.
The report states that more than 100 years of log-boom handling operations in the Cowichan-Koksilah estuary have littered the sea bed with anoxic zones of cut logs, bark, and sticks, causing widespread damage to salmon dependent eelgrass beds and forage fish populations.
This multi-year study indicates that the booms’ current positioning in crucial salmon migration corridors facilitates seal predation, which is one of the key factors in the correlation between declining Pacific salmon populations and burgeoning harbour seal density.
"Stseelhtun (salmon) are an integral part of our spiritual and cultural identity and they have been hit hard by the loss of marsh habitat, climate change, logging, and log-boom operations in our territory," said Cowichan Tribes Chief Cindy Daniels (Sulsulxumaat).
"I commend our Luxumexun (Lands and Self Governance) department, BC Conservation Foundation and Pacific Salmon Foundation for their long-term commitment to this study which has delivered concrete data demonstrating the level of crisis our relatives, the salmon, are experiencing. With these results, we look forward to working with government, industry, and partners to take actions to reverse these impacts before it is too late.”
Results from the study indicate that the presence of log booms has a statistically significant negative impact on adult Chinook terminal survival. They have made it easier for harbour seals to prey on salmon. Further, this impact is exacerbated by low flows, preventing adult Chinook from migrating into the river and away from predation pressures in the lower river and estuary.
As climate impacts become more severe, the negative impacts of log booms in key migration corridors and low river flows will increase, the study said.
Based on the study results, the Conservation Foundation has developed a series of best-management practices specific to the Cowichan-Koksilah estuary designed to limit, restrict, and offset damage to fish and fish habitat.
Such listed strategies include: situating the booms in deeper water where ocean-going ships already anchor and onshore log limbing and cleaning practices.
“Indigenous knowledge and Western science both indicate that the current log booming operations in the Cowichan-Koksilah estuary are degrading the estuarine environment physically, chemically, biologically, and ecologically,” said Jamieson Atkinson, program manager at the BCCF’s Aquatic Research and Restoration Centre.
“With climate forecasts calling for increasing drought periods, this study’s findings highlight the urgent need for effective management strategies to ensure the survival and recovery of wild Pacific salmon stocks.”
Michael Meneer, president and CEO of the Pacific Salmon Foundation, said salmon need people to take actions within their control to support their recovery.
“This study, led by Cowichan Tribes and BCCF, presents us with a clear path forward to collaborate with industry and Crown government to update log-boom storage practices,” he said.
“The recommendations set out in this report will have immediate and long-term benefits for recovery and resilience of Pacific salmon who depend on healthy estuaries during their migration.”
