Brook Trout Salvelinus fontinalis
> Brook Trout were introduced to Oregon from the East Coast through stocking in the early 1900’s.
> Brook Trout do not occur in the mainstem Willamette River, but are found in cold headwater streams in the Cascade Mountains.
> Like Bull Trout, Brook Trout are chars. They hybridize and nonnative Brook Trout are a significant threat to native Bull Trout populations.
Identification Tips
> Brook Trout have light markings on a dark background. They have yellowish wavy worm-like markings along the back and they have dark wavy markings on the dorsal, adipose, and caudal fins. Their sides have pink or red spots with blue rings.
> Their pectoral, pelvic, anal, and caudal fins often have white outer sides adjacent to a narrow black band on the leading edges. Their caudal fin is barely forked, almost straight. • Their mouth is large; the upper jaw extends past the eye.
> During spawning males upper and lower jaws elongate. Male coloration also intensifies during spawning.
Natural History
> Brook Trout live in cold streams, while others move downstream into lakes and ponds. Some populations on the east coast are sea-run but not in the Columbia River basin..
> They usually spawn in the fall between September and November. Females excavate nest in riffles with fine gravel. Females lay between 100 and 5000 eggs, which hatch after 50 to 100 days, depending on temperature and other conditions. Alevins remain in the gravel during yolk sac absorption before entering the stream habitat as young fry.
> Brook Trout generally live 4 to 8 years.
Range
> Brook Trout are found in Eastern Canada to the western side of Hudson Bay, South along the Atlantic coast, the Great Lakes, and in the Mississippi basin from Minnesota and Northern Georgia. In the Willamette River basin, they are established into high lakes and upper tributaries.
Size
> Stream-living Brook Trout generally grow to 6–8 inches (15–20.3 cm), while those that live in lakes may reach 18–28 inches (46–71 cm) and 5 – 8 lb (2.25–3.6 kg).
Habitat
> Brook Trout prefer cool, clear waters that are well oxygenated. They are found in mountainous headwater streams of larger rivers and lakes. Many fish barren lakes have been stocked with Brook Trout.
Diet
> Brook Trout diet is comprised of invertebrates, including zooplanton and aquatic insects, and fishes. Among fishes, they may prefer sculpins.
Management And Conservation Actions
> Brook Trout is a non-native species that has negative impacts on other salmonids, in particular on Bull Trout, by out-competing it and even hybridizing with it. ODFW is implementing Brook Trout eradication programs in eastern Oregon, it may be a matter of time before the Brook Trout population of the Willamette River receives similar actions.
References
For more information, see references.