Fleaflickr02,

As Carcassman indicated, habitat was not used to set any of the salmon spawning escapement goals in the early 1970s. As far as I know, there were no escapement goals for any species prior to US v WA. My recollection is that escapement goals for Chinook, chum, and pink were based on the average escapements for the period of record, which I think went as back as 1968 at the most (for Chinook). I don't think any serious spawning escapement estimates were made for anything prior to that time.

The exception to averages was coho. Zillges used and developed a habitat based model in 1976 that actually wasn't and still isn't half bad. Turns out it under-estimated habitat because a lot of small water bodies that coho use weren't included in the Williams stream catalog of 1975.

As co-management evolved, both state and tribal biologists agreed that escapement goals should be based on something more solid than average escapements that occurred more or less by coincidence. The Ricker model was generally preferred, and the intent as I recall was to "probe" with high, medium, and low escapements to determine the best or "correct" goal. The thought was that since run size escapements are usually high or low, the needed range of escapements would be observed within the coming years.

Well it was easy to get medium and low escapements with predicted returns, probably (IMO) because over-fishing of Chinook and coho in Puget Sound was an already established pattern. But in order for the model to give a good fit to data, you need some really high escapements, not just medium, low, and slightly higher than medium. No party was willing to give up the amount of harvest for a number of years that would be necessary to really fill the graph with some high escapement numbers. The Ricker curve can only give a value based on the data points that are entered, and since few or no high points are included, the curve is skewed lower than it might otherwise be. I don't know if any PS Chinook escapement goals have been changed from the original averages or not. My guess is not, because status quo is nearly always more comfortable in the human condition than change, especially change that might be accompanied by pain, as in not harvesting some hypothetical paper salmon.

C'man,

I thought the Lk WA sockeye escapement goal was based off of the estimated smolt capacity and productivity of the lake, which was based off Lk WA prior to METRO and the lake clean up that began in 1968, which significantly reduced its productivity. There is plenty of spawner-recruit data to make an estimate, and I believe the model kicks out a number in the 100,000 to 150,000 range. The co-managers could change the goal if they wanted, but again, it's about that human condition thing, and not science after all.

Sg