AuntyM-
Did not mean to dis-respect you! I often hear that the low rate of repeat spawners in Washington is evidence that over fishing had occured. My point is that is not necessarily so.

You are correct of course that having more fish on the spawning grounds will mean more eggs in the gravel. And yes it has been my experience that repeat spawners consistently have more eggs than first time spawners. It is easy to imagine that have those additional eggs is important; especially for population stability and every effort should be made to avoid selection against those fish (most commonly occurring by harvesting kelts).

Believe it or not I have thought a fair amount the question about selection for or against a repeat spawner trait. I think I understand how selection against size works for those Chinook or how removing the biters lead to the non-biters. However I can not think of how fishing on incoming runs selects against the likelyhood of repeat spawning -would not those fish likely to repeat and those not to repeat be equally likely to be caught in the fishery? In fact the potential selection that I can think would be selecting for more repeat spanwers not less.

If there is a genetic trait for repeat spawning then those fish surviving to repeat spawn would likely have that trait and with their increased numbers of eggs contribute more of the trait to the next generation leading to more repeat spawners.

Maybe some in this discussion with a better understanding of steelhead, steelhead behavior and steelhead fisheries can explain what selection occured against repeat spawning.

Tight lines
Curt