Home Page This Department


Pygmy Whitefish


Progress in pygmy whitefish habitat

Pygmy whitefish benefit from restoration efforts that improve stream habitat in the CRMW upstream of Chester Morse Lake. These actions include removing human-caused barriers to pygmy whitefish movement, decommissioning many forest roads that deliver sediment to streams, improving maintenance of other roads to reduce fine sediment inputs, and adding large woody debris (LWD) to enhance instream habitat.

Measuring Success for Protecting Watershed Habitats
We document all our efforts in preventing or containing toxic spills, in preventing and suppressing fire, and in the amount of invasive plants controlled or removed.
View more information on habitat protection metrics.

Measuring Success for Aquatic and Riparian Habitat Restoration
We measure the additional miles of stream accessible to bull trout as a result of removing artificial fish passage barriers, amount of sediment reduction in streams as a result of streambank stabilization, and number and location of LWD replacement projects within and adjacent to streams that flow into Chester Morse Lake. Bank stabilization at road crossings has been implemented at the Rex River, which has important pygmy whitefish spawning habitat.
See aquatic and riparian habitat restoration metrics.

Measuring Success for Road Decommissioning and Improvements
We document the amount and location of roads that are decommissioned or improved, and estimate the reduction in the amount of sediment delivered to streams that flow into Chester Morse Lake.
See road decommissioning metrics.

Pygmy Whitefish Research and Monitoring Studies

Annual Pygmy Whitefish Spawning Surveys
The status of adfluvial bull trout in the watershed is monitored by conducting annual spawning surveys. Spawning surveys document number as well as temporal and spatial distribution of bull trout redds in the upper Cedar River, the Rex River, and several smaller tributary streams. These data provide important information to assess changes in spawning population numbers through time.
View pygmy whitefish spawning metrics.
View Bull Trout and Pygmy Whitefish Spawning Survey Protocol (pdf).

Pygmy Whitefish Mark-Recapture Study
An HCP study investigating the return frequency of pygmy whitefish in the Cedar and Rex rivers was initiated in 2005. Pygmy whitefish are captured during the spawning run and implanted with a PIT (passive integrated transponder) tag which uniquely identifies them. The timing and frequency of return during subsequent spawning runs is currently being investigated.

For the unique characteristics of riverine spawning pygmy whitefish, view the presentation (pdf) at the American Fisheries Society Conference in September 2011.

Bull Trout, Rainbow Trout and Pygmy Whitefish Acoustic Telemetry Studies
SPU biologists follow the vertical and horizontal movements of bull trout, rainbow trout and pygmy whitefish in Chester Morse Lake. Acoustic tags are surgically implanted in fish and send data including date and time stamps to a hydrophone array in the lake.
View Acoustic Telemetry Study Progress Presentation 2007 (pdf).


See slideshow of research on pygmy whitefish.

Pygmy Whitefish Timing to Hatch Study
Very little is known about the early life history of pygmy whitefish. An HCP project was completed that documented the length of time it took for pygmy whitefish eggs to hatch in natural river conditions. In 2012 the results were published in Northwest Science: Barnett, H.K. and D.K. Paige. 2012. Egg Development Timing for Riverine Spawning Pygmy Whitefish (Prosopium coulterii). Northwest Science, Vol. 86, No. 2

Pygmy Whitefish Body Morphology Study
The body width and depth of individual spawning pygmy whitefish was measured during field sampling in order to better understand body morphology of the species. These data help SPU managers consider screening requirements for engineering projects in Chester Morse Lake.
See Pygmy Whitefish Body Morphology Report 2007 (pdf).

Bioenergetics Model
University of Washington and SPU scientists are collecting data to create a bioenergetics model (pdf) that will better explain species interactions, dietary needs, and distribution of all fish species in Chester Morse Lake. Several components of the study include: diet analysis, acoustic surveys of Chester Morse Lake to document fish distribution through the year, and food resource availability through the year in the lake.

Chester Morse Lake Temperature Modeling
Portland State University and SPU scientists collected data from 2005 through 2008 to create a temperature model for Chester Morse Lake. The model helps predict how temperature regimes could change through the year at any given depth, based on various management scenarios of the reservoir. The model will help interpret the behavior of bull trout, rainbow trout, and pygmy whitefish observed in the acoustic telemetry study. View the Chester Morse Lake Temperature Modeling Project Description (pdf) and Temperature and Fish Habitat Model of Chester Morse Lake (pdf).