Feature Creature: The Brook Trout

The brook trout ( Salvelinus fontinalis ) is a species of fish in the salmon family. It is native to a wide area of eastern North America including most of Canada from the Hudson Bay basin east, the Great Lakes/Saint Lawrence system, and the Mississippi River drainage in the United States as far south as northern Georgia. Once plentiful in streams and rivers in these areas, brook trout - or "brookies," as they're known to anglers - have been greatly reduced by development in the eastern USA. Large populations remain in just 5 percent of the areas they inhabited before colonization of the United States, notably in Maine and the mountains of Vermont, New Hampshire, New York and Virginia.

A new three-year study of brook trout populations recently concluded that the popular sport fish has disappeared or markedly declined in nearly half of the eastern U.S. areas where it once thrived. The plight of the trout is detailed in a report to be released in May by a coalition of conservation groups, the U.S. Fish and Wildlife Service, the U.S. Geological Survey, fish and wildlife agencies from 17 states, and universities.

The brook trout prefers cool, clear waters in lakes, rivers, and streams, being sensitive to pollution and poor oxygenation. Brook trout are extremely sensitive to water temperatures above 68 degrees, conditions that often occur when stream and river areas are developed or lose shade.

"Brook trout are the canary in the coal mine when it comes to water quality," said Gary Berti of Trout Unlimited in a statement. "Declining brook trout populations can provide an early warning that the health of an entire stream, lake or river is at risk."

The species normally spends its entire life in fresh water, but some individuals— colloquially called "salters" or "sea run"—spend up to three months at sea in the spring, remaining within a few kilometres of river mouths. The fish return upstream to spawn in the late summer or autumn.

The detailed report will be used to guide future recovery and conservation efforts aimed at keeping brook trout off the endangered species list. The assessment is one project of a coalition of state and federal wildlife agencies and conservation groups that joined in 2001 to protect and restore streams and rivers for fish. The project has evolved into a national effort known as the National Fish Habitat Action Plan.

The National Fish Habitat Action Plan is patterned on a similar effort for ducks and other waterfowl begun in the 1980s.

States where brook trout have declined the most include Georgia, Maryland, South Carolina, North Carolina and New Jersey. The report assessed habitat used by both native fish and the offspring of hatchery bred fish stocked in streams. The brook trout study found that the fish have been eliminated from 19 percent of the territory they once occupied and greatly reduced in an additional 27 percent.

For more about the National Fish Habitat Action Plan, visit us online.