North Cascades National Park NPS Arrowhead
Bald Eagle
North Cascades - Homeward Bound NPS
Bald Eagle Forest Carnivores (martens) Kids on the Trail
Salmon and Juveniles
Juvenile Coho Bull Trout
Juvenile Coho
Bull trout and juvenile coho

River Caretakers

Bull Trout
Salvelinus confluentus

Northwest streams and lakes are like the Juvenile CohoSerengeti of Africa and the depths of the Pacific, as there's always a top predator who needs to eat. Predators are important to all ecosystems for they help to keep companion species (their prey) healthy and strong. The piscivorous bull trout is one such caretaker in the waters of North Cascades. It recycles the energy of the old and sick, while also feeding on the numerous young fish that inhabit mountainous streams and lakes. In salmonids, adult females can lay thousands of eggs of which only a fraction mature into adults.

The bull trout is a char, a close relative to the well-known Pacific salmon subgroup which include chinook, coho, sockeye, pink, chum, steelhead, and cutthroat. Char sport light spots on their dark backs, unlike the Pacific salmon which have dark spots on their light backs. Another important factor which distinguishes this threatened* salmonid is its dependency on very cold water, especially for spawning. This necessity isn't surprising since one of its closer relatives is the arctic char. Rarely does one find the bull trout spawning anywhere but in the cold, mountain reaches of rivers in the Northwest, where water temperatures are typically below 48 degrees Fahrenheit.

Two challenges for bull trout are the removal of forests from mountains and riversides and the introduction of exotic brook trout. Taking trees from steep slopes often causes erosion. The destruction of the riparian zone results in warm water. The ability of brook trout to interbreed with bull trout threatens the genetic integrity of the native fish. Brook trout also compete with bull trout for food and space.

See how well you can design an ideal habitat for bull trout in Reach for the Fish.


Notes from the Field
  Bull Trout Facts
  Skagit River Watershed
Bull Trout Project

ActivityCreate an ideal bull trout habitat in Reach for the Fish.

Backyard Discoveries
  Activity: Bull Trout Tag
  Critical Thinking: Top Predators of the Globe

The Eagle Eye
  Bull Trout
  Bull Trout in stream
  Brook Trout
  Ruby Creek Habitat


Glossary: adfluvial, anadromous, competition, exotic, fluvial, indicator species, piscivorous, predator, prey, reach, resident, salmonid, tributary
Links: Bull Trout Facts: U.S. Fish and Wildlife Service (227 KB, pdf file)
*The U.S. Fish and Wildlife Service listed the bull trout as threatened under the Endangered Species Act in 1999.
Lilly (half)
Lilly (half) Lilly
a Natural Resource Challenge education project made possible by Parks As Classrooms