So yeah... the 22650 escapement number was "made up" for the 1910's dataset.
But ya gotta remember, they fished long and hard back then... 7 days a week for months at a time. It's certainly possible they were capable of fishing the runs down to escapements of 20-25K or even less.
Escapements of 23K producing runs of 70K is a recruit per spawner ratio that's barely over 3:1.... definitely in the realm of believable.
If true escapement was actually greater than 23K, it probably wasn't by much.
"Let every angler who loves to fish think what it would mean to him to find the fish were gone." (Zane Grey)
"If you don't kill them, they will spawn." (Carcassman)