In 1939, construction of Grand Coulee Dam blocked anadromous fish from 1,835 linear stream kilometers of spawning and rearing habitat in the upper Columbia River, causing the extinction of upper Columbia River Chinook (O. tshwaytscha), coho (O. kisutch), sockeye (O. nerka), and steelhead (O. mykiss).  Collectively, these fish accounted for approximately 1.1 million adult migrants to the upper Columbia River annually (Scholz et al. 1985).  The completion of Grand Coulee Dam also altered the natural ecology of the area by inundating about 243 river km of the upper Columbia River, creating Franklin D. Roosevelt reservoir.  Inundation of the upper Columbia River and subsequent hydro-operations changed the system from a river to a lentic habitat, leading to resident fish extinctions of redband, cutthroat, and bull trout (Bryant and Parkhurst 1950; Earnest et al. 1966).  The loss of wild, indigenous anadromous and resident fishes combined with major environmental changes resulted in a substantial ecosystem perturbation to the upper Columbia River.  

In the 1980’s, the stakeholders around Lake Roosevelt began requesting a return of a fishery in the reservoir, and began their campaign by starting up the volunteer net pen project.  Today, the Washington Department of Fish and Wildlife (WDFW), Spokane Tribe of Indians (STOI), Colville Confederated Tribes (CCT)), and Lake Roosevelt Development Association/Volunteer Net Pen Project are cooperating in a comprehensive artificial production program to produce kokanee salmon (Oncorhynchus nerka), rainbow trout (Oncorhynchus mykiss) and redband trout for annual releases into the reservoir.  The Lake Roosevelt Fisheries Evaluation Program was developed to assess the effect of the supplementation program on native resident fish and the ecology of the reservoir, and to assess the effect of hydro-operations on the artificial production program, the native fishery, and the Lake Roosevelt ecology as a whole.

The Evaluation Program’s primary objectives are to monitor and evaluate the performance of the Lake Roosevelt artificial production program and to assess the impact of reservoir operations on the fishery and ecology of Lake Roosevelt.  

FY2009 Work:

Limnology and Fisheries Monitoring:  We plan to complete water quality, chlorophyll and zooplankton community surveys to monitor physical, chemical and population indices for lower trophic levels.  Through fish surveys, we plan to collect fish length, weight, identifying markings, origin, species, and diet data to assess wild and hatchery fish population status and age structure, fish condition and growth, production, habitat use, and predation effects.  The primary purpose of these activities is to measure shifts in fish community structure, identify changes in growth rates of fish, and determine fish feeding behaviors.  This data will assist managers in determining whether hatchery fish are interacting with wild fish, if growth has changed over time, and whether food is limiting.  Understanding long-term changes potentially provides insight into how the fish community is evolving.  The information will be used to create informed recommendations regarding hatchery stocking strategies, fish regulations and other management decisions to minimize impacts to wild fish and lower trophic levels while maximizing the success of the hatchery program.   We also plan to estimate population size, age, health and habitat use of predators with tested walleye indexing techniques (Fall Walleye Index Netting-FWIN), and analyze the redband trout pilot study conducted at Sherman Creek Hatchery to assess early life stage rearing success at Sherman Creek.

Creel:  We plan to assess hatchery fish recruitment to the fishery, annual harvest and catch rates, the economic value of the fishery, the number of wild and hatchery origin fish harvested, and the growth and size of fish harvested from the Lake Roosevelt fishery using reservoir-wide and supplemental creel.  The creel was re-designed in 2005 and if necessary we will refine the creel analysis program and the design and protocols for creel data collection based on the assessment of the effectiveness of the new protocols in 2009.

Model:  The Lake Roosevelt Ecology Model is under minor revision to incorporate additional information from the Spokane Arm of Lake Roosevelt.  Current model permutations indicate that the Spokane Arm contributes a significant portion of the nutrients to Lake Roosevelt that supports the dominantly pelagic food resources.  Once the updates are complete we plan to work with Dr. Wells (Portland State University) and Dr. David Beauchamp (University of Washington) to complete model runs with PSU staff (if necessary) to begin looking at specific water use scenarios and their impacts.  If necessary we will work with PSU & UW staff to improve, refine, and streamline capabilities of the model, including refining the bioenergetics link as it relates directly to outputs of the CE-QUAL-W2 model and provide recommendations for the appropriate spatial and temporal inputs of data into the fish bioenergetics portion of the previously described modeling efforts.  We also plan to complete training of STOI and/or WDFW staff to use the models with reduced assistance from the modelers.

Tag Returns: We plan to conduct paired release studies of hatchery kokanee and redband trout to determine the best stocks and release strategies to maximize harvest and egg collection while minimizing entrainment and negative effects to wild fish.  Two tag drawings will be performed (April and October) as an incentive for anglers to return Floy ® tags and fish information.

Fall Kokanee Studies: We plan to monitor potential competitive interactions amongst wild and hatchery origin fish based on changes in growth, age structure, and diet overlap and evaluate return performance of fry releases.  We plan to collect hatchery kokanee eggs and milt to enhance hatchery kokanee production on Lake Roosevelt.

Acoustic Kokanee Study:  We plan to utilize temperature and depth sensitive acoustic transmitters on kokanee to determine their seasonal habitat use.  We will be able to determine whether kokanee make diel migrations into warm sub-optimal temperatures to feed on zooplankton in the photic zone, the location, duration and extent of vertical migrations into sub-optimal water temperatures and potentially to identify unknown areas of thermal refuge utilized by kokanee during the critical summer months.  These findings will be incorporated into the Lake Roosevelt Bioenergetics Model.  

Winter Diet:  One important piece of information missing in the diet data are winter diets (mean size and length of Cladocerans) of kokanee and rainbow trout.  This is an important piece of the Lake Roosevelt Ecology Model - Bioenergetics linkage for understanding how reservoir operations might effect fish production in Lake Roosevelt.  We plan to collect biological data from fish (lengths, weights, scales/otoliths for aging and origin, and stomach contents) collected via gill netting surveys in January-March 2010.

Upper Columbia River Trap Studies:  We plan to estimate immigration of fish from Canada into Lake Roosevelt.  Data will help managers determine when upriver kokanee enter Lake Roosevelt and evaluate the size at immigration.  Results will be used to adapt kokanee release strategies in attempts to mimic wild kokanee behaviors.  

Public Outreach and Coordination:  We also plan to continue public outreach and coordination efforts through the Kettle Falls Water Festival and the Lake Roosevelt Student Discovery Week.  In September 2009 and May 2010 we plan to participate in outdoor events teaching students about invertebrates, pollution, the environment and Lake Roosevelt.  Coordination will remain a critical component of the Evaluation Program in order to foster interaction and communication between Lake Roosevelt co-managers, researchers, the net pen coordinator, and hatchery managers and personnel.  We will organize and/or participate in LRFEP meetings, Lake Roosevelt Management Team meetings, Lake Roosevelt Hatchery Coordination Team meetings and other regional meetings necessary to the successful implementation of the program.