K. R. Bestgen, K. A. Zelasko, and G. C. White. Monitoring ...

TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY.................................................................................................................... 3
INTRODUCTION ................................................................................................................................7
STUDY AREA....................................................................................................................................8
METHODS.........................................................................................................................................8
RESULTS AND DISCUSSION...............................................................................................................9
Early life stage razorback sucker data needs and use..........................................................9
Larvae and early juvenile life stage sampling……............................................................11
Middle Green River................................................................................................11
Lower Green River.................................................................................................17
Colorado River Basin.............................................................................................18
Additional early life history data needs.............................................................................19
Light trap sampling efficiency and colonization studies........................................19
Taxonomic verification of larvae...........................................................................22
Large juvenile and adult life stage data needs and use......................................................23
Large juvenile and adult sampling and analysis................................................................25
Green River data, fish distribution, and macrohabitat use...................................26
Green River abundance, survival, and capture probabilities................................31
Colorado River data, fish distribution, and macrohabitat use..............................36
Colorado River abundance, survival, and capture probabilities..........................38
Simulations to guide sampling effort and stocking evaluations........................................38
Simulation methods ...............................................................................................38
Survival simulation results....................................................................................41
Abundance simulation methods.............................................................................43
Abundance simulation results................................................................................43
Uncertainties......................................................................................................................45
Data analysis and reporting needs.....................................................................................47
CONCLUSIONS.................................................................................................................................47
RECOMMENDATIONS.......................................................................................................................50
ACKNOWLEDGEMENTS....................................................................................................................52
REFERENCES...................................................................................................................................53
Suggested citation:
Bestgen, K. R., K. A. Zelasko, and G. C. White. 2012. Monitoring reproduction, recruitment,
and population status of razorback suckers in the Upper Colorado River Basin. Final
Report to the Upper Colorado River Endangered Fish Recovery Program, U. S. Fish and
Wildlife Service, Denver. Larval Fish Laboratory Contribution 170.
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