A number of recent studies shown the fact that many stocks of Pacific salmon are threatened with extinction. For example, the Wilderness Society estimates that naturally reproducing Pacific salmon are mostly extinct or imperiled in 56% of their historic range in the pacific Northwest and California.(Francis, Mantua, Hare) because of this fact, many scientists are trying to determine the areas of risk for North Pacific salmon population and find the ways to reduce the risk …showed first 75 words of 557 total…

…showed last 75 words of 557 total…as Pacific hake Merluccuis productus and jack mackerel Trachurus symmetricus, which can prey heavily on juvenile salmon in the south. Predation is considered to be the most significant source of mortality for juvenile salmonids in the marine environment. 3. Water temperatures optimal for growth of juvenile salmon are often exceeded off British Colombia in June and off Southeast Alaska in July and August. Waters that are too warm decrease food-conversion efficiency in salmon. The observed active