Originally Posted By: Carcassman
All the selective breeding in the world is not going to let a fish grow to age 4 or 5 at present fishing patterns. They have to live long enough. Regardless of size, what is the age distribution now vs. the 60s? They are getting younger.

Plus, there is a real problem in the ocean with food quality. Size at age is decreasing in recent years due to dietary issues. They need food to eat.

I have to agree with Carcassman here. The idea of selective breeding came before we even had the hatcheries to do it. My own limited experience at hatcheries they took the biggest bucks in the pool and used those to spawn all the hens.
There is a cost involved with selective breeding as well, both in dollars and in numbers of fish. My Dad invented a self feeding system at a fish farm. Problem was 20% of the fish ate 80% of the food while most of the rest of the fish starved. Our hatchery releases would go way down if we only released 20% of the fish. Would these fish come back larger and have larger offspring? Perhaps. Or maybe they would return as jacks.