Steelhead spawning escapement goals were set based on a model intended to seed available habitat to capacity. MSH/MSY is the statistical opposite; it doesn’t care how much or how little of the available habitat is used, only what the theoretical sustainable harvest is – which we have observed hasn’t worked out apparently for any fish population in the world.
Now that makes sense. So how about that land your house is on? I guess we need to go ahead and give them everything they are "entitled" to due to the fact that this great thread got a little too scientific for you and now you want to throw the over-emotional liberal curveball to the plate. Nice try. Thanks to Salmo and really all of you for participating in one hell of a discussion. Coach:beer2:
I thought the issue was MSH/MSY. Now you're switching gears to address the level of precision in the wild steelhead spawning escapement goal model.
Is it an "accurate predictor?" No. "All models are wrong. Some models are better than others." Somewhere I have the name of the Wisconson science professor who alledgedly made that quote. The steelhead model is based on juvenile fish surveys in 12 river systems where habitat was seeded to capacity by the available indicators. That produced parr production estimates per unit area for 4 stream gradient indexes. Potential parr production was converted to numbers of female spawners based on data from the river basins where data were available. Those were extrapolated to river systems around the west side of the state, and maybe others; I'm not sure. As it turns out, it's a better fit for some river systems than for others. Surprised? Is it any good? Well, it has served a critical conservation purpose where the alternative is even less desirable IMO.
The model received a modicum of criticism from a lot of biologists. And they recognize its shortcomings. And they didn't have a better model to offer as an alternative. The principle critics, as I recall, were some tribal fishery biologists who advocated setting escapement goals based on the MSY Ricker spawner/recruit curve. In every case, escapement goals would be very significantly lower using that model.
"The principle critics, as I recall, were some tribal fishery biologists who advocated setting escapement goals based on the MSY Ricker spawner/recruit curve. In every case, escapement goals would be very significantly lower using that model."
salmo g., you missed the part where you lectured me about MSH/MSY not being used. i accepted your arguement.
you instead stated that a statistical model is being used. ok fine.
the issue then becomes, how is WDFW 'tuning' that statistical model??? that is, you make a prediction, you observe reality, they don't match. what happens to the model parameters?? or are the same parameters simply used over and over again producing the same mismatched results??
and please don't fall back on 'something is better than nothing' notion of prediction. you and i both know that the statistics involved here are statistically insignificant and the only 'tool' you have is to correct the error variance via observation each and every year.
so the question to you is: is the statistical model being corrected as a result of observations???
Perhaps I owe you an apology. It was beginning to look to me like you were more interested in bitching about WDFW than discussing why several of us here don't see much benefit in quitting fishing for wild steelhead.
In the arena of statistical modeling, the steelhead escapement model is crude. However, in the realm of what's available and necessary for fisheries management in the PNW, I'd say it's probably average, maybe somewhat better.
Tuning the model can be done from two ends. Either from adult spawning escapement count/estimates or from field data on parr production. As far as I know, and Smalma would be closer to this than I, only one river system steelhead escapement goal has been changed since first set in about 1984. That is the Skagit.
The method was to compare spawner:recruit performance with the parr production model. Higher escapements above about 8,000 haven't produced higher subsequent brood returns. The highest return of about 16,000 was from a brood year escapement of 8,200 if I recall. The Ricker MSY escapement goal is around 4,000 or slightly less, again, as I recall. The Skagit Sytem Cooperative and WDFW agreed to revise the escapement goal downward from the parr production model estimate of 10,000 to 6,000.
To tune the model from the habitat end would require sampling parr production in every river system you wanted to refine, and conduct that sampling every year. The costs are prohibitive, and the most likely benefit would be either to not modify the escapement goal at all, or in my estimation, revise it somewhat downward for most watersheds. So in my estimation, the benefits are not worth the cost. If the result was to revise escapement goals downward, the result would be to predict some harvestable wild steelhead in rivers where they are not harvestable now. Again, the value in either sport harvest or commercial harvest is not enough to offset the cost of the work that would be required to do the fine tuning.
One of the concepts I find difficult to sell outside the fish management community is that the management objectives for conservation and utilization can both be met with management models that are pretty imprecise. Yet they offer sufficient precision to achieve conservation goals on average - provided they are actually followed (my little dig at the Hoh, Queets, and Grays Harbor policy decisions).
I'm with the liberal camp, and we dont claim him.
and smalma a couple things. A question: what data sets are the MSY/MSH management strategies built around. Also, Salmo, what work are you basing your claim that wild steelhead dont spawn with hatchery. Certainly it seems obvious that hatchery fish are spawning in the wild and although it is with limited success, like you said yourself, the spawning effort of that wild fish is void if spawned with a hatchery mate. Whether survival to smolt age is lower, or ocean survival is lower (or likely both) we know that hatchery spawning in the wild produces almost no recruits. While this may seem a bit of a tangent, the question becomes, how do we know hatchery fish arent spawning with wild. Particularly on tribs where the timing of the wild is earlier any way and the densities may be lower than later in the season so the sexual selection is not as effective at weeding out the hatchery weaklings. Also, I've heard that WDFW read counts dont even start until after march 15, is that true, and if it is wouldnt they miss many chambers creek redds which had been mossed over/moved by highflows?
Got me kevin. In my uneducated ways, I released the fish unharmed. . I will admit they are an excellent sportfish, although no match in fight to our native steelhead, or in agression to the fly to our native sea run trout.