Salmon school in Farmstead World — animal in the game, and what it is on a real farm.
Salmon are anadromous fish: they hatch in freshwater, mature at sea, and return to the river of their birth to spawn, which is why ocean fish farms and river hatcheries belong to the same supply chain.
Farming them in net pens takes the guesswork out of a fish that used to be whatever the boats landed; Atlantic salmon is now the single most farmed high-value fish in the world.