"Mother Nature does a pretty good job dealing with uncertainties climate change, for instance by producing a diversity of populations," explains Schindler. "In terms of fisheries, we need to have a longer- term vision for the viability of populations; the populations that are strong now are not necessarily going to be strong in coming years, so we need to protect weaker populations too, as insurance for the future."
Protecting weaker populations is a challenge not only in salmon, but also in other species like tuna and cod. Managers must reduce fishing pressure below the levels that the stronger populations can tolerate, or distribute fishing pressure to protect diversity within stocks. The authors argue that in addition to protecting existing population diversity, we must also preserve and protect the variety of habitats that generate population diversity in the first place.
Many salmon rivers, including the Sacramento River in California and the Columbia in Washington, once enjoyed a high degree of population diversity and productivity. However, decades of heavy fishing, habitat degradation and reliance on hatcheries have dramatically simplified populations in these rivers. This has resulted in intense boom-and-bust cycles and frequent fishery closures. In British Columbia, major salmon rivers like the Skeena and Fraser have some populations that are highly depres
|Contact: Liz Neeley|
Communication Partnership for Science and the Sea