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Background

Background. Loss of production from dam construction/operation Habitat loss, migration barrier, exotic predators/competitors Beamesderfer et al. 1995 , Parsley and Beckman 1994 , DeVore et al. 1995 , North et al. 1993 Increase subsistence fishing opportunities

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Background

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Presentation Transcript

  1. Background • Loss of production from dam construction/operation • Habitat loss, migration barrier, exotic predators/competitors • Beamesderfer et al. 1995, Parsley and Beckman 1994, DeVore et al. 1995, North et al. 1993 • Increase subsistence fishing opportunities • In kind, out of place mitigation • Measure 10.4A.5 (NPPC 1995) • Put, grow, and take sturgeon fishery • Cultured and/or wild fish transfer

  2. Goal • Quantify and assess critical uncertainties limiting the planning and development of a put, grow, and take white sturgeon fishery in Oxbow and Hells Canyon reservoirs. Mid-Snake sub-basin summary (pg 117)

  3. Brownlee 5665 ha Oxbow 468 ha 19 km Hells Canyon 980 ha 35 km

  4. Hells Canyon Reservoir

  5. Collaborative Process • ODFW • Jeff Zackel • Tome Rien • Ray Beamesderfer • IPC • Jim Chandler • Ken Lapla • U of I Genetics Lab • Paul Anders • ISRP (ISRP2000-7) • IDFG • Don Anderson • Tim Cochnauer • Nez Perce Tribe • Dave Statler • Nancy Hoefs • Rick Orme • CRITFC • Blaine Parker • Chris Beasely

  6. Feasibility ? • Minimal entrainment of stocked sturgeon thereby achieving and maintaining a harvestable population in the project area. • Sufficient growth and survival (production) to achieve and maintain a harvestable population of sturgeon. • Appropriate long term source to achieve and maintain a harvestable population. • Minimal risk to the down stream sturgeon population.

  7. Experimental Population 750 sturgeon (14 fish / km) • 500 Hells Canyon, 250 Oxbow Reservoir • PIT tag and externally marked Collaborative Process with Co-managers • Appropriate initial source of cultured and/or wild sturgeon

  8. Entrainment • Entrainment • Maintain 50 sonic tags in Hells Canyon, 25 in Oxbow Reservoir (10% of experimental population) • Monitor Hells Canyon forebay and tail race with stationary recording receivers • Entrainment Potential • Mobile surveys in Oxbow/Hells Canyon • Seasonal habitat use, travel time and distance • Entrainment of sturgeon from Oxbow

  9. High Potential Moderate Potential Low Potential • Daily Travel • Season • Water Year • Limnology

  10. Production • Bi-annual sampling • Set lines, angling • Stratify effort according to density (tracking data) • Survival • Mark re-capture estimators, CPUE, sonic tags • Intensive mark re-capture in third year • Growth • Quantify individual growth and population biomass

  11. Stock Source • Location, type (wild/cultured) • Genetic makeup (BPA project 19902200) • Long term availability • Number and available age classes • Potential disease concerns • Acquisition and transport costs

  12. Assessing Risk • Entrainment • Parameters • Entrainment, seasonal habitat use, duration and timing of spill, travel time and distance, limnological variables • # stocked vs # down stream • Fishery Potential • Parameters • survival, growth, catch rates, entrainment • Stocking vs Harvest (numbers / biomass) • Genetic Risk • Parameters • Stock source, survival, entrainment, age at maturity, stocking density, Ne of source and wild population • Probability of genetic effect

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