All About Brook Trout

Brook Trout

Scientific name: “Salvelinus fontinalis

The brook trout goes by several names like eastern brook trout, brook char, speckled trout, brookie, and squaretail. They are freshwater fishes native to eastern North America in both the United States and Canada. The name Brook Trout is a misnomer. These fish are actually in the Char genus “Salvelinus,” not the trout genus, “Oncorhynchus.” In other words, they are more closely related to char fish like lake trout, bull trout, dolly varden, and arctic char than they are to true trout. Char and trout are subgroups of the salmon family, “Salmonidae.”

Brook trout thrive in clean cold water. When water temperatures or in-stream sedimentation increases, brook trout tend to disappear from the picture; therefore, they’re considered an indicator species, like the proverbial canary in a coal mine. Wild brook trout populations indicate the water quality and overall health of the aquatic environment that they live in.

Brook trout is the state fish of Michigan, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Vermont, Virginia, and West Virginia. It’s also the provincial fish of Nova Scotia. Source

What do brook trout look like?

For starters, like all other char fish, brook trout have light spots over a dark background. This is the opposite color scheme from what true trout have. True trout species have dark spots over a light background.

Brook trout have swirling yellow lines on their olive greenbacks, dorsal fins, and tail fins in a wormlike pattern called vermiculations. They also have olive to dark green sides sprinkled with round yellow spots and red spots with blue borders.

Their bellies are white with orange or red overtones. During the spawning season, their belly often becomes very orange or red. Their lower fins, which include their pectoral, pelvic, and anal fins, are red with a thin black streak on the outer edge that is, in turn, lined by a thicker white stripe. Their tails are olive green with a pink overtone. Additionally, their tails are only slightly forked. This leads to the squaretail name that they’ve been given.

Brook trout also have a large mouth that extends back past their eye.

Native range

The brook trout’s original range extends over a large portion of eastern Canada at the north. It begins in Newfoundland and extends west to the western side of Hudson Bay. It extends south through most of the basin that drains into the great lakes and part of the Mississippi River drainage and east to the Atlantic basin and south along the Appalachian Mountains. The southernmost extent of the brook trout’s native range is in northern Georgia.

All or part of the following U.S State and Canadian provinces lie within the brook trout’s native range.

  • Minnesota
  • Wisconsin
  • Iowa
  • Illinois
  • Michigan
  • Ohio
  • Georgia
  • Tennessee
  • North Carolina
  • South Carolina
  • Virginia

  • West Virginia
  • Pennsylvania
  • Connecticut
  • New York
  • Massachusetts
  • Maryland
  • New Jersey
  • Rhode Island
  • Maine
  • New Hampshire
  • Nova Scotia
  • New Brunswick
  • Newfoundland
  • Labrador
  • Quebec
  • Ontario
  • Manitoba

Unfortunately, the brook trout has disappeared from much of its native range. Wild brook trout have been expatriates, or their numbers are significantly diminished in nearly half of the subwatersheds in their historical range. What’s more, the majority of large rivers in the brook trout’s native range no longer have self-sustaining wild populations. The majority of the remaining wild brook trout population exists in fragmented segments in headwater streams within their original range. Source

One major problem that they have is that they don’t do well when they have to compete for food and space with introduced brown trout and rainbow trout. They’re not as aggressive as these invaders, and the brook trout population dies out when they’re forced to compete with these non-native fish.

An even bigger problem than competition from non-native fish is habitat degradation and loss. Brook trout began to disappear from the northeastern United States in the late 19th century as streamside forests were cleared to develop the land. Some streams became dammed up with sediment since there was no longer any streamside vegetation to keep the sediment from washing into streams.

Some of the former brook trout streams in the Appalachians are dead of fish due to acid mine drainage.

Introduced Range

Ironically in the western United States, brook trout are often the introduced non-native fish that is out competing the native cutthroat trout. In some cutthroat habitats, brook trout is now an invasive species. In fact, they were a factor in the eradication of Lahontan Cutthroat Trout from Lake Tahoe. Source Brook trout have been introduced in the following U.S states. and Canadian provinces.

  • Arkansas
  • Alaska
  • Arizona
  • California
  • Colorado
  • Hawaii
  • Idaho
  • Missouri
  • Montana
  • Nebraska
  • Nevada
  • New Mexico
  • North Dakota
  • Oregon
  • South Dakota
  • Texas
  • Utah
  • Washington
  • Wyoming

  • Alberta
  • British Columbia
  • Saskatchewan
  • Northwest Territories

Brook trout habitat

Brook trout do best in cold, well-oxygenated lakes and streams with good water quality. These fish do not tolerate water warmer than 68 degrees Fahrenheit (20 C). Additionally, they need a ph—level in the 5.0 to 7.5 range.

Riverine fish or the version of these fish that live their entire lives in rivers or streams will be hanging out beneath undercut banks or near fallen trees or boulders. They need these kinds of features for shelter and also to break the strength of the stream current. Small streams will produce smaller fish that will be a maximum of 10 inches long and live for an average of three years. Larger brookies come from deeper waters of larger rivers, lakes, or saltwater estuaries. Brookies from these better habitats can live up to 6 years and attain much larger sizes.

As mentioned earlier, some of their habitats have problems with acidic mine runoff. Additionally, acid rain, which is caused by coal-burning power plants, factories, and automobiles, is a problem in some of their habitat. While acid rain is still a problem, it was more so in the late twentieth century.

What do brook trout eat?

Brook trout feed on a wide variety of organisms, including aquatic insects, terrestrial insects, and both aquatic and terrestrial invertebrates. The larger forms of these fish, such as lacustrine and sea-run brook trout, are piscivorous, which feeds on small fish. They’re not picky and are opportunistic feeders. Larger brookies will also feed on the occasional frog or even a small mammal such as an unlucky mouse.

Coaster brook trout

“Coaster brook trout” are mainly potamodromous brook trout from Lake Superior. The term potamodromous refers to freshwater fish that migrate, for instance, to spawn, but they stay in freshwater. Historically there were coaster brook trout in all three of the upper Great Lakes, which consist of lakes Huron, Michigan, and Superior. They were famous for their abundance and their large size. The 14.5-pound world record brook trout was more than likely a coaster. It was caught in 1916 on the Nipigon River, which flows from Lake Nipigon to Lake Superior.

As early as the 1880s, the brook trout population in the great lakes was in severe decline. A big factor in this decline was habitat degradation brought on by man-caused changes to the watershed.

Factors such as logging, road building, and railroad building allowed greater volumes of the spring runoff to run off the land too quickly, carrying with it a heavier load of sediment to clog streams and cover spawning beds. Farm runoff also had a detrimental effect on coaster trout numbers. Today these fish have been expatriated from lakes Huron and Michigan, and although they’ve made somewhat of a comeback, lately, they’re still threatened with expatriation in Lake Superior.

Salter brook trout

Salter brook trout or sea-run brook trout are anadromous. Anadromous fish live in saltwater but return to freshwater to spawn. Their historical range in the U.S once took in most of the Atlantic coastal rivers, streams, and estuaries from Maine down to Chesapeake Bay. Salter trout streams were the first destinations on every sport fisherman’s bucket list due to the numerousness and the size of these fish. In the 1820s, the noted statesman from New Hampshire and Massachusetts, Daniel Webster, reportedly caught a 14 1/2 pound salter brook trout on Long Island in the East Connecticut River (since named Carmans River). This fish wasn’t officially recorded, but it would have tied the current world record brook trout if it had been.

These fish began to dwindle with the advent of the industrial revolution. As streams were dammed or diverted for various purposes, such as mills or cranberry bogs, the fish began to disappear. Today salters are rare below the Gulf of Maine. As you travel north into Canada, you’ll find them to be more abundant. Many of the Rivers and streams that drain into Hudson Bay are home to giant Salter Brook Trout.

Can Brook Trout Live in Saltwater?

Is a Brook Trout a Trout?

Brook trout life history

The timing of the spawning season varies somewhat with the geographical area, but in most of their native range, brook trout spawn in October and November. Some brookies spawn in lakes. However, most of the time, their spawning habitat is in rivers and streams. Spawning brook trout seek gravel bars areas with enough current to provide ample oxygenation, such as in rivers, spring-fed streams, or on lake beds with gravel bottoms and upwellings of spring water. Brook trout are also sensitive to temperature. Spawning occurs in water that is between 40 and 50 degrees Fahrenheit.

The female constructs a depression in the gravel called a redd. They do this by using their tails to fan away the gravel, silt, and other materials. Redd is another name for a spawning bed. After constructing her redd, the female will lay up to 5000 eggs. After the male fertilizes them, the female covers the eggs with gravel.

The eggs have to stay free of silt and continuously be washed over by oxygenated water, or they will not survive. It will take 50 to 150 days for the eggs to hatch, depending on the temperature of the water. At this point, the fry still remains in the redd until their yolk sac is absorbed. The vast majority of mortality, whether it be due to predators, disease, or starvation, will occur within the first year of their life. If they make it to the end of their first summer, they will be around four inches long.

Generally, at 2 years of age, they will reach sexual maturity, and it will be the first year that they spawn. They will spawn every year thereafter. If conditions are optimal, they will live for 5 or 6 years.

Conservation efforts

As I’ve mentioned, brook trout are doing well in some parts of their native range, and in others, they’re struggling or have been completely expatriated.

There are organizations that are restoring brook trout environment and working to restore brook trout to their native range.

Quoted from their website, “the Eastern Brook Trout Joint Venture is a unique partnership between state and federal agencies, regional and local governments, businesses, conservation organizations, academia, scientific societies, and private citizens working toward protecting, restoring, and enhancing brook trout populations and their habitats across their native range.”

Trout unlimited of the U.S and Canada is also very proactive in restoring brook trout to their native range.

Also, look at the Sea-Run Brook Trout Coalition.

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