columbia river basin fish and wildlife program annual ...

I. COMPLETED PROJECTSNone.II. FY 1990 ONGOING PROJECTSPROJECTNUMBERTITLEPROJECT STATUSSCHEDULE AND MILFSTONFS83-465 Quantification of Hungry HorseReservoir Levels Needed toMaintain or Enhance ReservoirFisheries - MDFWPProiect Officer: D. JohnsonQbiectives: 1. To study theeffects of reservoir drawdown.2. To develop a predictivemodel of hydro operations onresident fisheries, and recommendseasonal drawdown levelscompatible with the needs ofthe fish.Date initiated: April 1, 1983Results/Conclusions: Reservoir drawdownhas adverse effects on benthic macroinvertebratesand zooplankton, can increasecompetition between fish, andmakes juveniles more accessible topredators. Fall drawdown is particularlydamaging to cutthroat growth rates.1. June 30, 1990: Biological model for thereservoir will be completed and runs will bemade concurrently with the Systems AnalysisModel. The biological model has beencritically reviewed and will be improvedby researchers at the University of Washington.83-467 Quantification of LibbyReservoir Levels Needed toMaintain or Enhance ReservoirFisheries - MDFWPmeet Officer: 0. JohnsonQbiectivel: 1. To study theeffects of reservoir drawdown.2. To develop a predictivemodel of hydro operations onresident fisheries, and recommendseasonal drawdown levelscompatible with the needs ofthe fish.m~nitiated: April 1, 1983 1. June 30, 1990: Biological model for thereservoir will be completed and runs will beResults/Conclusions: Gill net sampling made concurrently with the Systems Analysisindicates fluctuations in kokanee Model. The biological model has beennumbers. The reservoir model now in- critically reviewed and will be improved byeludes a hydrologic component downstream researchers at the University of Washington.to Duncan and Corra Linn dams.2. Work on fish entrainment through theLibby Dam penstocks and effects of operationson the river fishery will begin in FY 1990to increase utility of the reservoir model.