Backlash,

Guess I'm a little late. Obsessed has pretty well covered the territory here for you. I'll try to augment his post a bit for you.

Ocean survival is the single largest factor affecting the size of a salmon or steelhead population, on average. There are some exceptions, like a 100 year flood and so forth. Ocean survival is beyond human control, and beyond human influence - at least we would like to think that.

Sockeye and spring chinook are somewhat less adversely affected by the dams than are fall chinook due mainly to differences in smolt size and juvenile migration timing, I believe.

Next, by what yardstick do you call this year's return of sockeye and spring chinook large? The yardstick of very severely depressed run status, I take it. Recall that the power planning council's report on estimated historical Columbia River runs was 10 to 16 million. That was adult fish, not numbers of juvenile migrants. Don't get me wrong. I'm gratified that these returns are larger than seen recently, but in perspective they probably still fall in the catagory of pitiful remants.

Sockeye productivity benefits from good winter incubation conditions; yet this year's return was nailed by the 96 flood. Better than average lake rearing conditions could partially offset that. The next significant factor would have been the large spring runoff that made for an excellent smolt outmigration in 98. Clearly, conditions were more favorable for the Columbia sockeye than for the Snake River sockeye, with their expected return of 15 this year.

As for the spring chinook, they are predominantly hatchery fish, so natural environmental conditions in freshwater tributaries wouldn't be a major factor. Their performance this year is most likely attributable to good spring flows and outmigration and good ocean survivals. Hmmm, doesn't look like humans did much at all to favorably influence their survival. Well, consider what the run sizes would have been absent the dams!

Even with this seemingly good run, the dams "harvest" more fish (as juveniles) than any other source of human induced mortality, and often (but probably not this year's run) more than all other forms of human induced mortality combined.

That's my take.

Sincerely,

Salmo g.