Ives Island Study PRELIMINARY Results

The slides below comprise the preliminary findings of USFWS personnel on the Ives Island study area (See slide 1). The study is a joint U.S. Fish and Wildlife, Oregon Department of Fish and Wildlife and Washington Department of Fish and Wildlife study of the effects of flow on chinook spawning below Bonneville Dam.

Findings so far show that:

  • Lower River Tule Fall chinook salmon, lower river Bright Fall chinook and ESA listed Chum salmon spawn at this site.
  • Bonneville Dam flow level determines the amount of spawning habitat available to these fish at this site.
  • Flow level and fluctuating flow can eliminate spawning habitat, dewater redds and strand emerging juvenile salmon at this site.

The photos will take the longest to load. Some of the graphs from Excel look a little light - click on the thumbnail to see the graphs clearly.
Slide 1: Study Area Slide 2: Study Area Slide 3: Historic Photo Slide 4: Ives Island with gage locations Slide 5:
Slide1.GIF (198459 bytes) Slide2.GIF (208473 bytes) Slide3.GIF (184675 bytes) ives_gage.gif (480982 bytes)
Slide 6: Bonneville Flow 97 Slide 7: 1997 spawning Slide 8: Female Chum Slide 9: Early 1998 flows Slide 10: Location of index redd
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Slide10.GIF (188800 bytes)
Slide 11: Flow vs. depth at index redd Slide 12: Bonneville average flow Fall 1998 Slide 13: 1998 Flow < 125kcfs w/redds observed Slide 14: 1998 Flow at 125kcfs w/redds observed Slide 15: 1998 Flow > 150kcfs w/redds observed
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Slide 16: 1998 distribution of redds Slide 17: BON hourly flows Dec. 1998 Slide 18: Flows and stranding March 1999 Slide 19: Flows and stranding April 1999 Slide 20: Flows and stranding May 1999
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Slide 21: Flows and stranding June 1999 Slide 22: F&W personnel observing stranding Slide 23: Bonneville average flow Fall 1999 Slide 24: 1999 observations of Tule Fall Chinook Slide 25: View of spawning area
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Slide 26: View of spawning area Slide 27: Fish swimming in gravel Slide 28: 1999 Flow at 125kcfs w/redds observed Slide 29: 1999 Flow at 140kcfs w/redds observed Slide 30: 1999 Flow at 150kcfs w/redds observed
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Slide 31: 1999 Chum redds observed flow at 150kcfs Slide 32: Flow less than 125kcfs Slide 33: Flow at 125kcfs Slide 34: Flow at 150 kcfs Slide 35: 1998/1999 Chum overlaid on flow of 125kcfs
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Slide 36: 1998/1999 Chum redds at different flow levels Slide 37: 1998/1999 Fall Chinook redds at different flow levels Slide 38: All redds at different flow levels
Slide36.GIF (78398 bytes) Slide37.GIF (90833 bytes) Slide38.GIF (75405 bytes)




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Page last updated on: September 12, 2008

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