Everything you need to know about Maine brook trout

This story was originally published in December 2020.

No species of fish is more synonymous with Maine than brook trout. And you could argue that none is more important to the state. Brook trout is to inland Maine what lobster is to the coast, and is as much a part of the North Maine Woods brand as moose and loons.

The brook trout is a fascinating fish. Maine is blessed with several different life forms of brook trout. Brook trout is important to Maine, and Maine is important to brook trout. We must do all we can, and more than we do, to ensure that these unique wild native fish remain viable for generations to come.

Before tackling conservation-oriented topics in future columns, a brief introduction to brook trout is in order.

Originally called as Salmo fontinalis by naturalist Samuel Latham Mitchill in 1814, the brook trout is now called Salvelinus fontinalis. Salvelinus is a genus and part of the Salmoninae subfamily of Salmonidae family. The term fontinalis is Latin for “of or from a spring or fountain”, which refers to the cold, clean water where brook trout are found.

Brook trout is often referred to as eastern brook trout and occasionally brook trout, brown trout, mud trout, salmon trout, speckled trout and specs. In Maine they are sometimes called a squaretail, especially by older anglers. But by far the most common nickname is “brookie”.

The name brook trout is misleading. Brook trout is actually an arctic char, not a trout, and is more closely related to arctic char, lake trout, bull trout and Dolly Varden than to brown trout, rainbow trout or cutthroat trout. And brown trout are more closely related to Atlantic salmon and landlocked salmon than to brook trout.

Brook trout, however, is the most trout-like species of Arctic char and the most adaptable salmonid species. They can live in tiny freestone mountain streams, spring streams, prairie streams, flows, large rivers, small shallow ponds, deep sprawling lakes, brackish water estuaries and even salt water.

In many places where they live, brook trout are the predominant species, making up over 90% of the total fish biomass. This shows that they can live – even thrive – in conditions that many other species of fish cannot, even other salmonids.

Brook trout have been present in the Appalachians, the Great Lakes and eastern Canada for several million years. It is one of the most common native salmonids in North America, along with arctic char and lake trout. As far as the United States is concerned, brook trout are the most common native salmonid.

Brook trout are native to Labrador, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec and eastern Manitoba. They are found in the United States along the Appalachian Corridor from northern Maine to northern Georgia, parts of the Midwest, and most of the Great Lakes region. In many states they are the only native salmonids.

Native to both sides of the southern Appalachians, brook trout are found in waters that drain into the Gulf of Mexico as well as the Atlantic Ocean.

The southernmost population of native brook trout in the world is found in northern Georgia in the upper reaches of the Chattahoochee River in the Chattahoochee National Forest. The most northern populations are found in the extreme north of Quebec.

Unlike many other fish, brook trout are primarily classified at the species level, not the subspecies level. There are, however, two recognized subspecies of brook trout: the aurora brook trout and the extinct New Hampshire silver trout. Best described as a brook trout without a pattern or spots, the aurora brook trout is native to just two lakes in the Temagami district of Ontario.

Although the term is often used to describe populations at the watershed level, there are only two officially recognized strains of brook trout: northern and southern. The line denoting north versus south strain fish is located in the New River watershed in northern Virginia.

Once considered subspecies of brook trout, marine brook trout or northeast coast salters, and Great Lakes mountain brook trout are now considered life history strategies or northern strain brook trout life forms. Silver trout, an extinct subspecies of brook trout, were once thought to be a form of arctic char.

Brook trout can be purely fluvial, living and reproducing in moving water. They can also be adfluvial or born in a stream but living mostly in a lake or pond. Some brook trout live and spawn in lakes and ponds and are referred to as lake trout. Massachusetts recently documented what appears to be brook trout spawning in tidal waters. All brook trout build spawning grounds or depressions in the gravel.

Newborn brook trout are called fry or fry. They stay in the nest until they exhaust their yolk sac. Brook trout leave the spawning ground as fry and move to the shallows to feed on zooplankton. The next stage is the parr, identified by vertical stripes, which move to deeper water to feed on small insect larvae. The final stages are juvenile and adult.

Brook trout populations are most abundant where good in-stream spawning habitat is available. In cases where pond-dwelling fish use the spawning habitat in the lake, populations are generally more sparse. This is called recruitment, and high recruitment means high densities; low recruitment means low densities.

Brook trout in small streams rarely live for more than a few years. In large lakes however, especially in Canada, they can reach up to 10 years. In ponds and rivers, they fall somewhere in between. The oldest brook trout on record, a non-native, was nearly 25 years old and was found in a high-altitude lake in California.

The largest brook trout on record measured 30 inches long with an estimated girth of 20 inches and weighed 14.5 pounds. He was captured in the Nipigon River in Ontario in July 1915 and was probably a coaster. In 1827, Daniel Webster caught a speckled trout of about the same size in the East Connecticut River on Long Island.

About Edward Fries

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