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Lees Ferry Fish Monitoring

Lees Ferry Fish Monitoring. Lees Ferry Monitoring. How do Glen Canyon Dam operations influence the rainbow trout fishery?. Annual sampling Electrofishing Abundance, Size Angler Surveys Catch rates. Mean peak discharge = 18,823 ± 2,518 cfs Mean discharge = 12,816 ± 683 cfs.

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Lees Ferry Fish Monitoring

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  1. Lees Ferry Fish Monitoring

  2. Lees Ferry Monitoring • How do Glen Canyon Dam operations influence the rainbow trout fishery? • Annual sampling • Electrofishing • Abundance, Size • Angler Surveys • Catch rates

  3. Mean peak discharge = 18,823 ± 2,518 cfs • Mean discharge = 12,816 ± 683 cfs Modified low fluctuating flows 1991-2010

  4. 1996-HFE • Max-45,600 cfs • Mean-15,235 ± 529 cfs

  5. 2000-LSSF • Max-30,900 cfs • Mean- 8,355 ± 22.4 cfs

  6. 2003-TSF

  7. 2004-TSF

  8. 2004-HFE • Max-41,900 cfs • Mean- 11,789 ± 395 cfs

  9. 2005-TSF

  10. 2008-HFE • Max-42,500 cfs • Mean- 12,830 ± 326 cfs

  11. 2011-EqF • Max-26,200 cfs • 2011 Mean- 19,326 ± 380 cfs • May-Aug Mean-24,280 ± 257 cfs

  12. 2011 – 6.9 ± 1.35 fish/min • 1991-2010 - 3.1 ± 0.52 fish/min 2003-2005 TSF 2000 LSSF 2008HFE 2011 EqF 1996 HFE 2004 HFE

  13. Lees Ferry Standardized Monitoring Juveniles

  14. Lees Ferry Standardized Monitoring 306-405 mm 306-405

  15. Lees Ferry Standardized Monitoring >405 mm

  16. 2011-EqF 2008-HFE

  17. Rainbow trout <152 mm 2011 EQ 2008 HFE

  18. Rainbow trout <152 mm 2008 Cohort 2011 EQ 2008 HFE

  19. Average total length by year

  20. Lees Ferry Creel 1991-2011

  21. Low Angler Catch Rate High Angler Catch Rate 0.4 fish/hr 1.4 fish/hr 0.6 fish/hr 1.5 fish/hr

  22. Additional species captured during sampling

  23. Native Fish in the Tailwater to Glen Canyon Dam

  24. Mainstem Fish Monitoring

  25. Rainbow trout

  26. Rainbow trout 2000-2011 GCD

  27. Rainbow trout 2000-2011 GCD

  28. Rainbow trout 6-fold decrease in CPUE from RM 58  63 GCD

  29. Brown trout

  30. Brown trout 2000-2011 GCD

  31. Common carp

  32. Common carp 2000-2011 GCD

  33. Flannelmouth Sucker

  34. Flannelmouth Sucker 2000-2011 GCD

  35. BlueheadSucker

  36. BlueheadSucker GCD

  37. Fish Management? • Vision • DFC… Desired Future Conditions • ORV… Outstanding and Remarkable Values • Compromise • Do you want big fish or a lot of fish? • Fish are not the only resource being managed for downstream of GCD • Feasibility • Fiscal • Legal • Logistical • Political

  38. Fish Management? • Implementation (a few tools) • Add fish • Translocation • Augmentation • Stocking • Remove Fish • Mechanical Removal • Chemical Removal • Change in regulations • Habitat manipulation • Advantageous or disadvantageous for certain species • Flows • Temperature • Sediment • Food base • Feasibility

  39. Fish Management? • Uncertainty/Patience • Adaptive management • Utilize best available information to design experiments to drive resource towards desired condition • Experiment • Monitor resource/resources • Analyze data and compare current resource/resources to that of desired condition • Go back to step 1 as necessary to reach desired conditions • Continue to monitor • Feasibility • Public Outreach • Throughout the process

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