If you check the profession entry on my profile, you will see "cattle rancher." This title needs a good deal of qualification; I'm not one of those big operations with 100's or 1000's of cattle. We just have a small herd, usually running in the range of 8-12 head, whose job is to eat grass (and hence cut down on mowing requirements) and produce at least one steer per year to supply our family's beef. The cattle breed; we pick out a steer each year and feed him out for a month or so before butchering.
I am starting to feel like a "fish rancher" as well, again with qualifications. Not one of those big aquaculturists who raises and sells (or perhaps kills

) tens or hundreds of thousands of fish, just a guy with a small apx 1 acre pond whose job it is to provide our family's fish. The fish breed; I feed them out during the warm months before removing some of them for butchering.
This year I am approaching the point where the pond will be able to produce all those eatin' sized fish closely enough to feel sure that it can and will happen. I have been taking out more medium BG (6" - 7.5", by this year's definition) than ever before. With breeding populations that provide plenty of fish - hundreds of BG, dozens of LMB and CC - showing up to eat feed every night, I feel pretty confident that I am not removing the amount of fish the pond is able to grow yet.
I don't know what the pond's sustainable yield will be, but plan on approaching that harvest level carefully, removing conservative numbers of predator fish and leaving the largest BG (especially males) in the pond while culling smaller BG. Hopefully the size of a "smaller" BG will continue to increase in the future. Trying to get a rough idea from literature, one might guesstimate that an acre could produce on the order of 100 lbs of BG per year; I am just now realizing that 100 lbs is a whole lot of nice, fat 7" BG!
Life is good. Any other fish ranchers out there?