Backlash2 - Salmo G. is correct is stating that ocean mortality is the single largest factor affecting run size. However, the dams are still the single largest factor affecting run size that is under human control.

Comparing run sizes between species, years, and rivers is tempting but it shouldn't be done because of differences in life history, weather patterns, and habitat. The real question is how large would the sockeye run be on the Columbia River this year if they didn't have to navigate through eight dams? My guess is that is would not be large, it would have been enormous.

That's the general life history pattern of Pacific salmon. When conditions are right (both freshwater and ocean), they can be enormously abundant. Unfortunately, the freshwater conditions in the Columbia Basin have not been good for a long time. So, when the ocean conditions become reasonably good, we get a "good" year class. But it's far from historical levels, and certainly not "enormously abundant", because the freshwater conditions remain degraded. Fortunately, the ocean gods are smiling upon us this year and we're getting good returns. Next year might not be so good. If the freshwater conditions were better, and we had far fewer dams, the fish would be in much better shape that they are today. But you probably already knew that....


------------------
MSB