columbia river basin fish and wildlife program annual ...

I. COMPLETED PROJECTSNone.II. FY 1990 ONGOING PROJECTSPROJECTNUMBER TITLE ECT STATUS SCHW AND WNFS87-99 Dworshak Dam Impacts Assessmentand Fisheries Investigation -IDFGPro-Officer: R. AustinDbiectives: 1. Assess thestatus of kokanee stocks in thereservoir.2. Document losses of kokaneefish in Dworshak Reservoir.through turbines at DworshakDam.3. Assess limnologicalparameters and evaluate impactsof reservoir management on thezooplankton community andkokanee production.Date initiated: July 1987 1. FY 1990: Continue baseline data collection.Results/Conclusions: Kokanee abundanceestimated from late June trawl data, was540,000 fish in 1989. Anglers harvested 2. FY 1991: Continue baseline data collection.171,331 kokanee at 1.3 fish per hour. Prepare final report coordinated with Project 87-407.Creeled fish averaged 246 mm and 121 g; recommendations will be made to the Council forYield was 3.1 kg/hr. Spawning escapement measures to protect, mitigate, and enhance residentwas similar to 1988 with 37,000 kokaneeobserved in five tributaries of thereservoir in mid-to-late September.Two-year old spawners (277 mm totallength) comprised the bulk of the run.87-407 Dworshak ReservoirInvestigation: Trout, Bassand Forage Species - NPTProiect Officer: R. Austinobiectives: 1. Assess thestatus of rainbow trout, smallmouth bass, and forage speciesin the reservoir.2. Assess changes in thesepopulations in relation toreservoir management.Date initiated: July 1987 1. FY 1990: Continue baseline data collection.Results/Conclusions: An estimated 2. FY 1991: Continue baseline data collection.152,700 angler hours were expended from Prepare final report coordinated with Project 87-99.March 1989 through February 1990 to catch Recommendations will be made to the Council fora total of 20,426 rainbow trout, 13,064 measures to protect, mitigate, and enhancesmallmouth bass, and 180 bull trout. resident fish in Dworshak Reservoir.Approximately 98% of the rainbow troutcaught were of hatchery origin. Overallgrowth of smallmouth bass is betterthan that reported for other smallmouthbass populations at similar latitudes.Fish production has apparently stabilized