Rainbow, brown, and brook trout are cold water fish which require well oxygenated waterbelow 65°F. They are cultured commercially in manynortheastern states. Pennsylvania and New York are theleading producers in the region.Most trout are grown in flow-through systems; althoughsome culturists currently reuse their water and afew use cages or net pens. Rainbow trout are marketed forstocking and as food fish. Brown and brook trout are stocked for recreational fishing; some are also sold as food fish.