MPM,
With few exceptions, hatchery fish have significantly lower reproductive efficiency in the natural environment. Based on data, that is an empirical fact. You decide if that's equivalent to gospel to you. After that, it's just math. If a Snider broodstock fish retains 0.85 (a realistic value) of a NOR wild fish, which is equal to 1.0, it is impossible for 0.85 x 1.0 = 1.0, which is what you get when two wild fish mate (1.0 x 1.0 = 1.0).
Coley,
The anecdotal data seem positive, but since I can't separate the emotional or visceral reports from the objective I can't make an accurate or probably even a useful conclusion. However it's entirely possible that January NORs (natural origin recruits) have increased due to the Snider program. I'd venture that it's between "more likely than not" to "far more likely than not." But that doesn't tell me what, if anything, has happened with overall basin productivity. My understanding is that the Duc is consistently "fully seeded" with spawners. If that is true, then the most the Snider program can do is restore some population diversity in terms of return timing that had likely been reduced due to high harvest pressure on Dec.-Jan. hatchery steelhead.
Juvenile steelhead can and do distribute and re-distribute widely within a watershed. I don't know of any evidence indicating that a habitat niche was lying vacant that could only be served by January adult returns. Further, while the average spawn timing of the Jan. adult returns is likely earlier than the average spawn timing of the March returns, it is equally likely that a complete overlap of spawn timing occurs, excepting that March returns cannot spawn before March, while a Jan. return might. Given that overlap, it falls within the "far more likely than not" that most Snider fish that escape the fishery will spawn with a wild fish, thereby reducing the reproductive efficiency of the wild fish. So the more Snider fish that survive to spawn, the greater the negative effect of the Snider program on the wild population as expressed by basin productivity.
The only way that I can think of for the Snider fish to add to system productivity is if the Sol Duc were in a watershed condition like say the Cowlitz, where anadromous fish have been re-introduced upstream of dams after a 40 year absence, or the mid-Columbia tributaries where the wild fish have been nearly extirpated. In those cases the steelhead habitat niche was nearly vacant, so reproduction, even at the lower efficiency of the many hatchery spawners, has been a near term positive benefit. This is where wild broodstock, or hatchery broodstock, programs have their greatest benefit to an ecosystem: in restoration or recovery of severely depressed or extirpated natural populations.
However, as those populations recover with increasing numbers of NORs spawning in the rivers, hatchery fish spawning in those same systems, where they were essential initially for recovery, will become an impediment to any eventual full recovery of wild steelhead populations. This is why I wrote in one of my posts above that wild broodstock programs, or hatchery programs in general, are at their best fit in systems that already have healthy wild populations because the negative impacts will be negligible.
Stam,
The problem seems to be the lack of evidence that the Snider program is either "fixed" or "broken." Does this mean you're happily in the camp of "blissful ignorance?" NTTAWWT.
Sg