Bull Trout

Description
The bull trout and the coastal Dolly Varden are close relatives. In fact, they are so similar that the name bull trout and Dolly Varden were used almost interchangeably until just a few years ago. Both are members of the char family. They have a green to blue-gray back, with silvery sides. No spots on the dorsal (back) fin. Yellow, orange or red spots dot its sides. The pelvic pectoral and anal fins have a white leading edge. They may weigh up to 32 pounds.

Native to Idaho, bull trout occur in most of the mountain creeks, rivers, and lakes. Although they are widely distributed, they are not abundant. They are well adapted to very cold environments, but are not very tolerant of warm water or sediment.

Life History
Bull trout spawn in October in areas with moderate stream current and good-sized gravel. The female digs a redd that may be a foot deep, and up to 3 feet by 6 feet across. Once spawning is complete, the female covers the nest by loosening gravel upstream and letting the current wash it over the nest containing the fertilized eggs. After spawning, the adults move into lakes or deeper pools to rest.

The eggs hatch in the winter and the small fish live in the gravel until early spring. The juveniles may remain in the stream or migrate to a lake. In lakes they grow rapidly and may reach 30 pounds. They are sexually mature within 4-6 years. Adult bull trout may spawn several times during their lives but may not spawn each year.

Feeding Habits
Juvenile bull trout feed on aquatic insects. As soon as they are large enough to eat fish, they do. The adults are predatory, eating primarily fish eggs of other fish.

Angling Techniques
It is illegal to harvest bull trout in Idaho. They are listed as threatened under the Endangered Species Act .

Bull trout are secretive and almost impossible to see in streams unless they are spawning. You will need to be patient to catch a glimpse.