Brook trout

The brook trout (Salvelinus frontinalis) is the only native trout we have in Frederick County. The brook trout is native to the eastern US and Canada extending from Georgia up to the Hudson Bay and westward into the Lake States. Brook trout are also known as speckled trout in Canada where many of these fish are found in larger lakes and ponds. Brook trout are very colorful fish having an olive to brownish back with white worm like markings (called vermiculations) across the top of the fish. Brookies have whitish sides often times having pink to red dots with a bluish halo surrounding them. The lower fins of these fish may have orange markings on them. The male trout develops deep reddish to orange color on their flanks during fall spawning season. Brook trout have a square tail which leads to the “squaretail” nickname given to them. Brook trout require cold, clear, well oxygenated water that lies within a narrow pH level. These fish can live in small streams, rivers, lakes, and are even found in Lake Superior. Stream inhabitants usually attain a size on 5-7 inches in length whereas lake run fish can attain a size of 5 pounds or more. Brook trout found in Lake Superior can grow to a size in excess of 10 pounds. Brook trout are voracious eaters, become mature quickly, and have a relatively short lifespan usually living 3 -5 years. Brook trout have a relatively high reproductive potential with females laying up to 400 eggs. Where they occur together, brook “speckled” trout and lake trout can hybridize to create a fish called a splake.

Brook trout are very demanding of site conditions and they are a good indicator of stream vitality. Only the cleanest and healthiest of streams can support viable populations of this fish. These cold water fish have been declining steadily throughout the east due to urbanization, sedimentation, stream temperature rise, stocking of nonnative fish especially brown trout, acid rain, and pollution. In Frederick County only a small fraction of our streams continue to support brook trout populations and they are usually at the upper reaches of the watershed in small streams. A comprehensive multi-state study and restoration program for brook trout was initiated in 2005 called the Eastern Brook Trout Joint Venture which was intended to assess brook trout populations, find healthy, breeding populations, and develop strategies for the protection of remaining viable populations and restoration of brook trout into suitable locations. This is ongoing project that involves many government and private organizations. The largest concentration of healthy brook trout waters in the US can be found in the state of Maine which contains nearly 90% of the brook trout waters found in the lower 48 states. Brook trout have been stocked outside their native range in the west and throughout the globe. In some areas these fish have become invasive pests harming native trout populations.

Article by FCFCDB member

Nature Note for 4/5/20