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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 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 Modified low fluctuating flows 1991-2010
1996-HFE • Max-45,600 cfs • Mean-15,235 ± 529 cfs
2000-LSSF • Max-30,900 cfs • Mean- 8,355 ± 22.4 cfs
2004-HFE • Max-41,900 cfs • Mean- 11,789 ± 395 cfs
2008-HFE • Max-42,500 cfs • Mean- 12,830 ± 326 cfs
2011-EqF • Max-26,200 cfs • 2011 Mean- 19,326 ± 380 cfs • May-Aug Mean-24,280 ± 257 cfs
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
Lees Ferry Standardized Monitoring Juveniles
Lees Ferry Standardized Monitoring 306-405 mm 306-405
2011-EqF 2008-HFE
Rainbow trout <152 mm 2011 EQ 2008 HFE
Rainbow trout <152 mm 2008 Cohort 2011 EQ 2008 HFE
Lees Ferry Creel 1991-2011
Low Angler Catch Rate High Angler Catch Rate 0.4 fish/hr 1.4 fish/hr 0.6 fish/hr 1.5 fish/hr
Rainbow trout 2000-2011 GCD
Rainbow trout 2000-2011 GCD
Rainbow trout 6-fold decrease in CPUE from RM 58 63 GCD
Brown trout 2000-2011 GCD
Common carp 2000-2011 GCD
Flannelmouth Sucker 2000-2011 GCD
BlueheadSucker GCD
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
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
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