In Cooperation with the Bureau of Reclamation, TSC, Denver, Colorado under the Multi- Species Conservation Program Work Task G-3 Adaptive Management Research Project and Conservation Measure RASU-6, Lower Colorado Regional Office, Boulder City, Nevada Techniques for Monitoring Razorback Sucker in the Lower Colorado River, Hoover to Parker Dams, 2006–2007, Final Report By Gordon A. Mueller, Richard Wydoski, Eric Best, Steve Hiebert, Jeff Lantow, Mark Santee, Bill Goettlicher, and Joe Millosovich Open-File Report 2008–1245 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DIRK KEMPTHORNE, Secretary U.S. Geological Survey Mark D. Myers, Director U.S. Geological Survey, Reston, Virginia: 2008 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Suggested citation: Mueller, G.A., Wydoski, R., Best, E., Hiebert, S., Lantow, J., Santee, M., Goettlicher, B., and Millosovich, J., 2008, Development of monitoring techniques for razorback sucker found between Hoover and Parker Dams, 2006–2007, Final Report: U.S. Geological Survey Open-File Report 2008-1245, 34 p. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted material contained within this report. ii Contents Abstract................................................................................................................................................................................1 Introduction .........................................................................................................................................................................2 Monitoring Techniques..................................................................................................................................................2 Impetus for this Study....................................................................................................................................................3 Objective ..............................................................................................................................................................................3 Monitoring Plans and Terminology .............................................................................................................................3 Relative Abundance.......................................................................................................................................................4 Adult Population Size.....................................................................................................................................................4 Sample Variance.............................................................................................................................................................4 Spawning Population.....................................................................................................................................................4 Methods ...............................................................................................................................................................................5 Study Location.................................................................................................................................................................5 Techniques ......................................................................................................................................................................5 Riverine Trammel Netting..........................................................................................................................................5 Hoop Netting and Electrofishing..............................................................................................................................8 Boat Surveys..............................................................................................................................................................11 Helicopter Supported Photography.......................................................................................................................12 Use of Aerial Photographs ..................................................................................................................................12 Camera Equipment................................................................................................................................................12 Results ................................................................................................................................................................................13 Trammel Netting ...........................................................................................................................................................13 Strengths ....................................................................................................................................................................14 Weaknesses ..............................................................................................................................................................14 Cost..............................................................................................................................................................................15 Labor........................................................................................................................................................................15 Equipment...............................................................................................................................................................15 Operating Costs.....................................................................................................................................................15 Sampling Efficiency..................................................................................................................................................15 Hoop Netting..................................................................................................................................................................15 Electrofishing.................................................................................................................................................................16 Strengths ....................................................................................................................................................................17 Weaknesses ..............................................................................................................................................................18 Cost..............................................................................................................................................................................18 Labor........................................................................................................................................................................18 Equipment...............................................................................................................................................................18 Operating Costs.....................................................................................................................................................19 Sampling Efficiency..................................................................................................................................................19 Boat Surveys .................................................................................................................................................................19 Strengths ....................................................................................................................................................................21 Weaknesses ..............................................................................................................................................................21 Cost..............................................................................................................................................................................22 Labor........................................................................................................................................................................22 Equipment...............................................................................................................................................................22 iii Operating Costs.....................................................................................................................................................22 Sampling Efficiency..................................................................................................................................................22 Helicopter.......................................................................................................................................................................23