Status and Habitat Use of Snake River White Sturgeon Associated with the Hells Canyon Complex Ken Lepla Project Biologist Technical Report Appendix E.3.1-6 Revised July 2003 Hells Canyon Complex FERC No. 1971 Copyright © 2003 by Idaho Power Company Status of Snake River White Sturgeon Associated with the Hells Canyon Complex Ken Lepla Project Biologist James A. Chandler Fish Biologist Phil Bates Fisheries Technician Technical Report Appendix E.3.1-6 Status and Habitat Use of Snake River White Sturgeon Associated with the Hells Canyon Complex Chapter 1 November 2001 Revised July 2003 Hells Canyon Complex FERC No. 1971 Copyright © 2003 by Idaho Power Company Idaho Power Company Chapter 1: Status of Snake River White Sturgeon TABLE OF CONTENTS Table of Contents............................................................................................................................. i List of Tables ................................................................................................................................. iii List of Figures................................................................................................................................ iii List of Appendices ...........................................................................................................................v Abstract............................................................................................................................................1 1. Introduction.................................................................................................................................2 2. Study Area ..................................................................................................................................2 3. Methods.......................................................................................................................................4 3.1. Collection Methods............................................................................................................4 3.2. Analysis Methods...............................................................................................................5 4. Results.........................................................................................................................................7 4.1. Swan Falls–Brownlee Reach .............................................................................................7 4.1.1. Population Abundance and Structure........................................................................7 4.1.2. Telemetry ...................................................................................................................8 4.2. Brownlee Dam–Hells Canyon Dam Reach........................................................................8 4.2.1. Population Abundance and Structure........................................................................8 4.2.2. Telemetry ..................................................................................................................9 4.3. Hells Canyon–Lower Granite Reach .................................................................................9 4.3.1. Population Abundance and Structure........................................................................9 4.3.2. Telemetry ................................................................................................................10 5. Discussion.................................................................................................................................11 5.1. Swan Falls–Brownlee Reach ...........................................................................................11 5.2. Brownlee–Oxbow–Hells Canyon Reaches......................................................................13 Hells Canyon Complex Page i Status and Habitat Use of Snake River White Sturgeon Idaho Power Company 5.3. Hells Canyon–Lower Granite Reach ...............................................................................14 5.4. Telemetry .........................................................................................................................16 6. Summary and Conclusions .......................................................................................................18 6.1. Swan Falls–Brownlee Reach ...........................................................................................18 6.2. Brownlee–Hells Canyon Reach .......................................................................................18 6.3. Hells Canyon–Lower Granite Reach ...............................................................................19 6.4. Telemetry .........................................................................................................................19 7. Acknowledgments.....................................................................................................................20 8. Literature Cited .........................................................................................................................20 Page ii Hells Canyon Complex Idaho Power Company Chapter 1: Status of Snake River White Sturgeon LIST OF TABLES Table 1. Summary of effort and catch (including recaptures) for white sturgeon sampled in Snake River reaches from Swan Falls Dam to the mouth of the Salmon River. ........................................................................................................25 Table 2. Abundance estimates for white sturgeon populations in Snake River reaches between Swan Falls Dam and Lower Granite Dam..................................26 Table 3. Mean length of white sturgeon 3 to 45 years old sampled in the Snake River from Swan Falls Dam to the mouth of the Salmon River. ................27 Table 4. Stage of maturity of white sturgeon sampled in the Snake River from Swan Falls Dam (RM 458) to the mouth of the Salmon River (RM 188).............28 Table 5. Summary of movement by telemetered white sturgeon in the Swan Falls−Brownlee reach of the Snake River. ..................................................29 Table 6. Summary of movement by telemetered white sturgeon in the Oxbow−Hells Canyon reach of the Snake River...................................................30 Table 7. Mortality and survival estimates for white sturgeon sampled in the Snake River between Bliss and Lower Granite dams............................................30 Table 8. Summary of movement by telemetered white sturgeon in the Hells Canyon−Salmon River reach of the Snake River.........................................31 Table 9. Mean relative weights based on fork length measurements for white sturgeon populations in the Snake River between Bliss and Lower Granite dams. ......................................................................................................................32 LIST OF FIGURES Figure 1. Map of Snake River reaches between Swan Falls Dam and the Salmon River that Idaho Power Company sampled for white sturgeon................33 Figure 2. Gear selectivity rates for white sturgeon sampled with setline and gill net gears in the Snake River. .......................................................................................35 Figure 3. Distribution of Snake River white sturgeon between Swan Falls and Lower Granite dams. Data below Hells Canyon Dam include sturgeon Hells Canyon Complex Page iii Status and Habitat Use of Snake River White Sturgeon Idaho Power Company sampled by the Nez Perce Tribe between the Salmon River and Lower Granite Dam...........................................................................................................36 Figure 4. Setline catch rates and hours of effort expended during sampling of white sturgeon in the Snake River from Swan Falls Dam to the mouth of the Salmon River. ........................................................................................................37 Figure 5. Gill net catch rates and hours of effort expended during sampling of white sturgeon in the Snake River downstream of Swan Falls Dam to the mouth of the Salmon River. ..............................................................................................38 Figure 6. Length-frequency distributions (adjusted for gear selectivity) of white sturgeon sampled with setlines in the Snake River reaches from Swan Falls to Lower Granite dams........................................................................39 Figure 7. Length-frequency distribution (adjusted for gear selectivity) of white sturgeon sampled by gill nets in the Snake River between Swan Falls and Brownlee dams.......................................................................................................40 Figure 8. Mean length-at-age and von Bertalanffy growth (VBG) lines for white sturgeon in the Snake River between Swan Falls and Lower Granite dams in graphs a) and b). VBG function for Hells Canyon−Lower Granite sturgeon population was estimated by Tuell and Everett (2001) using combined age data from IPC and Nez Perce Tribe 1997–2000 sturgeon surveys. ..................................................................................................................41 Figure 9. Length-weight relationships for white sturgeon sampled in the Snake River downstream of Swan Falls and Hells Canyon dams. ........................42 Figure 10. Relative weights of white sturgeon sampled in the Snake River between Swan Falls and Lower Granite dams. Length and weight data below Hells Canyon Dam were combined with sturgeon data