Engineering the Future for Wild Salmon and Steelhead
Ernest L. Brannon
Salmon are as much a part of western North American culture as they were to the native peoples of the Pacific Coast and the interior where big rivers eventually drain west into the Pacific. Present society does not depend on salmon to supply the major portion of its sustaining diet as was the tradition of the native people. Nonetheless, salmon are a significant part of the western North American legacy, and they evoke a similar level of quasi-religious fervor when the public perceives that salmon are in jeopardy.
It is important, therefore, to put the problem of declining wild salmon in perspective. Contrary to the impression that salmon are on the verge of disappearing, these great species of the Pacific actually increased abundance over the last 20 years, due largely to favorable marine conditions that benefit salmon growth and survival. Pink salmon Oncorhynchus gorbuscha returning to Prince William Sound, Alaska, for example, had their all-time record in 2003 with 57 million fish returning, which was approximately 10 times the average annual return from 1920s to the early 1970s. The total combined abundance of all salmon species in the Pacific reached their largest recorded return in the mid-1990s (Figure 1). Many wild populations, however, especially from British Columbia to California, are depleted, and some are at risk of extinction.
The problem, at least from the perspective of those that prefer to have only wild fish in our streams, is that in many cases, the large returns are the result of hatchery production. Up to 90% of the Chinook salmon O. tshawytscha returning to the Columbia River are hatchery-produced (Anderson et al. 1996). This is not new to anyone who is aware of the history of the fishery and water development in the West. Increased hatchery production was a decision by state and federal governments to mitigate for the loss of habitat resulting from the trade-off of wild salmon for the development of rivers to supply the economic needs of the growing population.