Fish and Aquatic Conservation

illustration of a Brook trout

Brook trout

Salvelinus fontinalis, (Mitchill, 1814)

Cool Facts

The maximum reported weight for a brook trout is 8 kg (17 lbs. 10 oz.). The maximum reported age for a brook trout is 24 years. Brook trout may hybridize with brown trout to produce infertile tiger trout. In Lake Superior, large brook trout will migrate into streams in the fall to spawn. This type of life history strategy is called adfluvial.

SIZE: Common length for brook trout is 24.6 cm (10.4 in) with the maximum reported length Being 86 cm (33.9 in) .

RANGE: Brook trout are native to eastern Canada and the northeastern United States. There range extends as far west as eastern Minnesota. The original range of the brook trout also includes the Appalachian Mountains, where they are still found in many high elevation streams as far south as Georgia.

HABITAT: Brook trout occur in clear, cool, well oxygenated creeks, small to medium rivers and within lakes. Within their native range, general upstream movements brook trout have been observed making upstream movements in early spring, summer and late fall. Brook trout have been observed making downstream movements in late spring and early fall. Some brook trout, more popularly known as salters, make runs to the sea in the spring as stream temperatures rise, but never venture more than a few kilometers from river mouths. These salters may remain at sea for up to three months.

DIET: Young brook trout feed on plankton and progress to insects until they are adults. Brook trout feed on a wide variety of organisms including worms, leeches, crustaceans, insects, mollusks, fishes, amphibians and also small mammals. The stomachs of some brook trout contained traces of plant remains.

Natural History

The brook trout are members of the char family. Brook trout prefer small spring fed streams and ponds with sand or gravel bottom and vegetation. This species prefers to spawn over gravel in either streams or lakes, with ground water percolation or in the spring fed areas in lakes.

Pre-spawning courtship of the brook trout begins with the male attempting to drive a female toward suitable gravel habitat to facilitate spawning. A receptive female chooses a spot and digs a redd. While the female brook trout is digging, the male brook trout continues his courtship activity, darting alongside the female and quivering, swimming over and under her and rubbing the female with his fins. The male spends a great deal of time driving off other males during this process. After spawning, the female brook trout covers the eggs by sweeping small pebbles at the downstream edge of the redd upstream. Once the eggs are covered, the female moves upstream to the end of the redd and then begins digging a new redd.

Brook trout normally mature in two years but may spawn after one year. These fish spawn between September and October. Brook trout fry will emerge sometime between February and April. Young brook trout normally seek shelter in submerged aquatic vegetation or shallow water near the shoreline.


Brook trout are the focus of a large scale restoration partnership known as the Eastern Brook Trout Joint Venture. The abundance of brook trout throughout their native range of the upper Midwest and Northeast has been reduced due to the loss of cold water habitat, largely due to land use.

The introduced of non-native trout and salmon compete for spawning and nursery habitat with brook trout.

Migration Behavior

Brook trout are a migratory species. Some of these fish spend their entire lives in freshwater and others called salters are born in freshwater and then migrate to the ocean for their adult lives and return to freshwater to reproduce.