That's true in that what spawns is what isn't killed. That is likely more common with hatchery than with wild fish because of lower exploitation rates. But yes, fish the **ck out a run and you get very little both in numbers and size.

Heck, one year when I was in hatcheries the adult coho were, in many cases, smaller that what was "always" called a jack. CWT's proved it. Plus, fecundity is directly related to size. Smaller females have fewer eggs......