I’m trying to see your point through the usual Naysaying. How can you have too many wild fish?
If there are enough wild fish then fishing above the trap would not have to be selective?

As is, the researchers must have made some assumptions or some complex calculations to differentiate survival from the loss due to predation, harvest or turn off for those tagged fish that weren't destined for McNary Dam . These were the types of things that made the earlier study about release survival rates so difficult to sort out.

Numbers seem too good for handling fish in the lower Columbia during warm water.

If 1% of the mixed stock area is wild, then 1 in 100 encounters needs release. Or, catch 99 per release. If half that population is wild, then every other fish is wild and must be released until such time as that stock health improves. We have been reducing the number of hatchery fish out there and have either kept constant or reduced the wilds.

To echo Darth Baiter's comments above....

My guess (based on how some of the past selective gear work has gone) is that these values, which stipulate McNary survival, are likely based on only a subset of the fish handled - those that they tagged that passed Bonneville. So, these values should probably be tempered with some more context. Not that they aren't likely pretty good, relative to other gears.

Unless Doc was there, at the trap, to help them ID the stock/run of fish and perhaps even the tributary/hatchery of origin at the time of tagging?

(good fun intended)

There are many layers to it. The fish stocks enter at different times. To make numbers up for purely discussion purposes, steelhead tagged in the Fall could be primarily summers bound for Idaho and the upper river. A different group of summers from those that enter in May and June. If they ran the net later in the Fall, when chum are the target, you would probably be in winters, none of which would go above McNary.

They have, or should have, a pretty good idea of which stocks would be encounters at any given time. It is likely, too, that an experienced person can identify stock (summer/winter, spring fall, tule/bright) and age only the stocks of interest.

The most logical place already exists and has for 80 yrs. No brainer, trap on each Bonneville fish ladder sort and distribute.

I'm sure everyone here would also lay down their gear and get in line for a fish handout at Bonneville? You know, just to further reduce fishing mortality...

Anybody who can sell the fish would wait in line.