An Upstream Battle: declines in 10 Pacific salmon stocks and solutions for their survival
This report profiles the current status and trends of 10 examples of salmon stocks in British Columbia that are considered to be in a severe state of decline. (There are many others.) These stocks were selected because they are geographically located within a region where a number of stocks of that species are in decline and the available data provide a reliable index of stocks status. They include four stocks of sockeye (Lakelse, Long, Nimpkish, and Cultus lakes), three of coho (Middle North Thompson, Brunette, and Cowichan rivers), and one each of chinook salmon (Nimpkish River), chum salmon (Viner Sound Creek), and steelhead (Keogh River). For each of the stocks, the available data on escapement, catch, and harvest rates are presented graphically since the early 1980s (or earlier, if data available). We have assessed the impact of human-related activities on fish-spawning and rearing environments in these watersheds, as well as changes in salmon survival at sea, for each stock.
The abundance of these stocks has declined by 70 to 93 per cent since the early 1990s. The decline appears to have been precipitated by poor marine survival. Estimates for South Coast chinook, coho, and steelhead indicator stocks show evidence of a major decline in marine survival rates in the early 1990s. Continued high harvest rates through the mid-1990s resulted in substantial declines for some of these stocks (e.g., Nimpkish River chinook, North Thompson River coho). By the late 1990s, harvest rates had been significantly reduced for most stocks, but abundances remain low due to poor marine survival and degradation of freshwater habitat.
While little can be done to improve marine survival of salmon, it is imperative that harvest rates remain at low levels until there are clear signs of recovery and measures are taken to improve freshwater production through the protection and enhancement of critical spawning and rearing habitat. Specific recommendations for improving freshwater production vary with species and watersheds. Recovery plans have identified specific projects to reverse losses in spawning habitat for sockeye and increase the productivity of freshwater rearing habitat for chinook and coho. In some instances (e.g., Lakelse sockeye, Cultus sockeye, Brunette coho), short-term augmentation of fry or smolt production is necessary to initiate recovery from very low abundance levels. For other stocks (e.g., Smith Inlet sockeye, Cowichan coho, Keogh steelhead), recovery is unlikely until there is significant and sustained improvement in marine survival.
At the end of this report, the David Suzuki Foundation provides a summary of key solutions to help protect and conserve salmon stocks in Canada, based on recommendations taken from this report and other published works by the Foundation.
These solutions include:
- Enforcement of habitat regulations
- Fishing selectively
- Precautionary management
- Legislated protection for endangered stocks
- Implementation of the Wild Salmon Policy