Cohoangler,

Yes, it's a bit more complicated than what I posted. OK, a lot more complicated. I wanted to present a simple description consistent with a 5-paragraph theme, instead of a 16 page essay. Natural mating and effective spawning is anything but random. It's another example of the more I learn, the more I know that I don't know.

However, if large male x large female wild matings consistently led to the highest average survival, then larger average size fish is what we would observe in the populations. Yet we don't. Other selective factors are at work, in addition to ocean predation and harvest pressure. Until we have a better notion of what is going on and controlling the population phenotypes, then trying to simulate what we observe in natural production populations in artificial production seems like the preferred route to me.

Fishyfeller,

Looks like you're a pretty quick study.

And as Todd, Milt, and Eyefish mention, the artificial production of fish, whether old school hatchery production or integrated wild broodstock or any other variation, inevitably leads to increased harvest rates on the wild native populations. And those populations in most instances are not abundant enough to consistently withstand the higher harvest rate that occurs.

Sg