Salmon don’t climb water jumps just because they feel like it, like hamsters using wheels. They migrate; and sometimes rivers are how they migrate.

To raise “buff” salmon, you’d need something that looks less like a fishery, and more like a private river with the upstream pointed in the right direction for their migratory instincts. And, since they wouldn’t want to turn around at the end, you’d need to pick them all up and haul them back to the beginning so that they would swim it again.