Progress in bull trout habitat
Bull trout benefit from restoration efforts that improve stream habitat in the CRMW upstream of Chester Morse Lake. These actions include removing human-caused barriers to bull trout 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.
See slideshow of road decommissioning program.
Measuring Success for Road Improvements and Decommissioning
Our success in road decommissioning and improvements will be measured by the amount and location of roads that are decommissioned or improved, and reduction in the amount of sediment delivered to streams that flow into Chester Morse Lake.
Measuring Success for Aquatic and Riparian Habitat Restoration
Our success in stream and riparian restoration will be measured by 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 stream bank stabilization, and number and location of LWD replacement projects within and adjacent to streams that flow into Chester Morse Lake.
See aquatic and riparian habitat restoration metrics.
See slideshow of the Cabin Creek habitat enhancement project.
Cabin Creek Habitat Enhancement Project
In 2008, SPU implemented a large woody debris project aimed at enhancing instream cover for juvenile bull trout in Cabin Creek. Wood was carefully placed in and above the stream to increase the amount of overhead cover available to fish through a reach that lacked abundant cover elements.
Measuring Success for Protecting Watershed Habitats
To measure our success in protection of bull trout habitat we will be documenting 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.
Bull trout research and monitoring studies
See slideshow of Bull Trout spawning surveys.
Annual Bull Trout Spawning Surveys
The status of adfluvial bull trout in the watershed was monitored from 2000 through 2011 by conducting annual spawning surveys. In 2001 we developed a Method for Biodegradable Redd Marking (pdf) that allowed us to track individual redds through the spawning year and avoid double counting by multiple observers. View our Bull Trout and Pygmy Whitefish Spawning Survey Protocol (pdf).
Spawning surveys documented 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 provided important information to assess changes in spawning population numbers through time. View annual numbers of redds, and spawning and rearing distribution in bull trout spawning metrics.
Both reservoir elevation and maximum streamflow during spawning influenced the spatial distribution of bull trout redds and demonstrated the importance of off-channel habitat in smaller tributaries. Scientific results can be found in:
- Barnett, H.K., D.K. Paige and W.C. Belknap. 2013. Impact of reservoir elevation during the spawning season on the distribution of bull trout redds. North American Journal of Fisheries Management 33(5): 917-925.
See slideshow of Juvenile Bull Trout & Rainbow Trout movement study
Juvenile Bull Trout and Rainbow Trout Movement Study
An HCP study investigating the early life history of bull trout and rainbow trout in tributaries of Chester Morse Lake was conducted in a joint effort between SPU and the USGS Columbia River Research Laboratory. Investigators monitored movement of juvenile bull trout and rainbow trout through the use of PIT (passive integrated transponder) technology in the upper watershed. See Juvenile Bull Trout and Rainbow Trout Movement Study (pdf).
Bull Trout, Rainbow Trout and Pygmy Whitefish Acoustic Telemetry Studies
SPU biologists followed the vertical and horizontal movements of bull trout, rainbow trout, and pygmy whitefish in Chester Morse Lake in 2005-2007. Acoustic tags were surgically implanted in fish and sent data, including date and time stamps, to a hydrophone array in the lake. View Acoustic Telemetry Study Progress Presentation 2007 (pdf).
Biologists tracked movements of spawning bull trout using acoustic tags 2006-2011. Previously unknown information was revealed, including that most bull trout made multiple trips between the lake and river during spawning season. Plus we found that the majority of time they spent in the river was during nighttime hours. Scientific results can be found in:
- Barnett, H.K. and D.K. Paige. 2013. Movements by adfluvial bull trout during the spawning season between lake and river habitats. Transactions of the American Fisheries Society 142(3):876-883.
Bull Trout Redd Inundation Study
A certain proportion of bull trout redds are spawned each year within a zone of the river that becomes inundated as Chester Morse Lake fills in the winter and early spring. A fine layer of sediment settles over these sites, and scientists are working to determine the effects on incubating bull trout egg survival and success of these redds to fry emergence View Inundation Study Progress Presentation 2006 (pdf).
Bull Trout Body Morphology Study
The body width and depth of individual juvenile bull trout was measured during field sampling in order to better understand body morphology of the species during early life stages. These data help SPU managers consider screening requirements for engineering projects in Chester Morse Lake. See Bull Trout and Rainbow Trout Body Morphology Report 2008 (pdf).
University of Washington and SPU scientists are collecting data to create a bioenergetics model 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. View the Bioenergetics Model Project Description (pdf).
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 Chester Morse Lake Temperature Modeling Project Description (pdf) and the final report Temperature and Fish Habitat Model of Chester Morse Lake (pdf).
Bull Trout Spawning Impedance
A geotechnical study was completed in 2007, providing information on whether a partial or complete physical barrier might develop at the Cedar and Rex River deltas during extremely low lake levels or a drawdown in Chester Morse Lake. Read more about Bull Trout Spawning Impedance.
Bull Trout Passage Assistance Plan
The Bull Trout Spawning Impedance study, along with future geotechnical investigations, will determine the need to complete a Bull Trout Passage Assistance Plan. This plan would outline methods for addressing partial or complete barriers to bull trout, rainbow trout, or pygmy whitefish movement during their spawning migrations.