Fun5,

I think that it is a somewhat economic decision to not plant fry...though there would be a higher egg to fry survival, the fry to smolt survival AT BEST would be the same. The difference we're talking about here, since fry to smolt survival is a very, very low percentage even at the best conditions, is only a few fish.

To put the money into collecting wild fish, spawning them, raising the eggs to fry, and then releasing them would be prohibitive when compared to the return on the investment, which would be literally a few fish.

FishDoc,

I think that the reason they would use that type of supplementation program on the Wenatchee River, and others that are similarly situated, is that the number of dams the fish have to traverse would mess up the usual high productivity that fish have at low densities.

In a normal river a run of ten wild fish might produce 20 or 30 adults, assuming that habitat is not the limiting factor.

In the Wenatchee a run of ten fish might all be killed by the first dam they reach, not to mention the other several they have to go by before they reach the river.

While the rule of higher productivity at lower densities is generally true, there comes a point where the density is so low that anything less than perfect can spell E-X-T-I-N-C-T-I-O-N.

Rivers like the Wenatchee and others in that part of the Columbia are using supplementation programs like that, and I believe that is the reason why. I don't think that they are using them to do that in any other situation, though some folks who operate or help out with broodstock programs think that they are, when they are actually just producing a higher quality hatchery fish to harvest. Not a value judgment on whether or not that is good, just a factual statement on what is actually going on.

Fish on...

Todd