The Lewis River Hydroelectric Projects - PacifiCorp

Lewis River Interpretive & Education Plan
spawning sites for them in the streams around Merwin). In Merwin, adult fish
are captured and spawned in October at Speelyai Hatchery, and the young fish
are reared there and in net pens. They are released in late spring.
Some years, Speelyai hatchery rears rainbow trout. These fish are hatched at
Merwin Hatchery, then, depending on space availability, may be reared in
Speelyai raceways before they are trucked up the Lewis River to stock in Swift
Reservoir.
Fish Habitat Enhancement
PacifiCorp operates an active fish habitat enhancement program. One of the
most visible components of this program is the “roundup” of floating woody
debris (logs and large branches) from Swift Reservoir. Large woody debris of
this sort is a very important component of stream habitat for fish; the logs and
branches shape and direct streamflow, providing in-stream habitat diversity
and protecting against erosion. Much of the large debris gathered from Swift
reservoir is used to help enhance in-stream habitat.
Fish Conservation (Bull Trout)
Bull trout (Salvelinus conflentus) are members of the char clan of the salmon
family. They are a key conservation species in the Northwest, as their
populations have been strongly affected by logging, dams, and other human
impacts. They have very narrow spawning requirements, which are met at
Cougar Creek and two other tributaries upstream of Swift Reservoir. Bull trout
require cold (temps below 10 degrees C), fast moving water with a substrate
of large gravel for spawning. For successful incubation, the eggs require
temperatures of less than 7 degrees C (egg development is faster in colder water).
Cougar Creek, a spring-fed creek, meets those requirements. Young bull trout
spend their first two years in the stream, eating aquatic insects and small fish,
before heading out to the lake. There, their primary prey are juvenile kokanee.
Bull trout may live 12-15 years and may spawn several times during their lives.
Bull trout are a federally protected species, and fishing for them is illegal.
Anglers who accidentally catch bull trout are required to release them
immediately. Unfortunately, bull trout are somewhat similar in appearance
to some other species in the reservoirs, so identification information is a key
resource for anglers. The presence of light-colored spots on bull trout helps
distinguish them from cutthroat and rainbow trout (which have dark spots). Bull
trout can be distinguished from brook trout (another light-spotted salmonid) by
the lack of black markings on their dorsal fins.
PacifiCorp works to conserve bull trout by protecting critical spawning habitat
(such as Cougar Creek) and by providing public education to anglers who may
catch bull trout.
Sea Reach Ltd • 146 NE yamhill Street • Sheridan, OR draft 3 • November 2008 • page 83