Atlantic salmon are a benthopelagic fish, preferring to inhabit the bottom half of an open-water environment. They are anadromous and can be found in fresh, brack, or salt water depending on the season and age of the fish. They are not found south of the Chessapeake Bay and can be found very far north. The Atlantic salmon feeding grounds are just off the southern tip of Greenland.
Atlantic salmon closely resemble the common Brown trout, but can be distinguished easiest by taking a peek at the roof of their mouth. Atlantic salmon will have a single row of under-developed teeth; the Brown trout will have a double row of well-developed teeth.
Although benthopelagic, most Atlantic salmon do their foraging high in the water column by the surface layers and even the surface itself. Juveniles feed mainly on aquatic insects (blackflies, stoneflies, caddisflies and chironomids, mollusks, crustaceans and fish; adults at sea feed on squids, shrimps, and fish. Larger salmon feed on fishes such as herring, alewives, smelts, capelin, small mackerel, sand lance and small cod.