While in Alaska I visited a Salmon hatchery, in particular the Macaulay Salmon Hatchery in Juneau. Here is a link to the site that has a nice overhead camera shot of the facility and its history.
The site itself I found to be pretty amazing. The salmon are hatched here, in the fresh water, and raised to be a decent size, and let out into the stream, which leads to the Pacific Ocean. In the ocean the fish keep growing until they are the large salmon you see in all the documentaries (especially the ones where the bears are swiping them out of the water with their huge paws), and then the really amazing part starts - the Salmon find their way BACK all the way from the Pacific Ocean to this hatchery where they were first raised. Apparently the Salmon can smell the unique fresh water of their home out of all the water in the Pacific Ocean and get right back to the spot where they were born.
The hatchery isn't owned by the state; it is run by a non-profit. The state benefits because all of these fish are born and raised and then come back into state waters, which is a boon for commercial and sport fishermen. The center makes money (or breaks even) on visitor tours, letting select commercial boats take a share of the salmon that congregate outside their facility during peak season, and also from the fish post-fertilization that they sell to become fertilizer or dog food (you can't really eat the salmon after they have finished spawning because they literally rot from the inside out as they change from salt to fresh water).
If you are ever in Alaska and it is in season I recommend that you visit one of these hatcheries - it is quite interesting. They also had a big aquarium of locally caught fish and starfish which was very good, which could help when the fish weren't around.