................................................................................................................................... 2 ACKNOWLEDGEMENTS ............................................................................................................ 3 TABLE OF CONTENTS ................................................................................................................ 4 LIST OF TABLES .......................................................................................................................... 6 LIST OF FIGURES ........................................................................................................................ 7 INTRODUCTION .......................................................................................................................... 8 WALLA WALLA BASIN BULL TROUT ............................................................................................ 8 BULL TROUT USE OF THE MAINSTEM COLUMBIA AND SNAKE RIVERS ......................................... 9 STUDY AREA ............................................................................................................................. 10 WALLA WALLA BASIN ............................................................................................................... 10 MAINSTEM COLUMBIA RIVER .................................................................................................... 11 METHODS ................................................................................................................................... 12 BULL TROUT SAMPLING AND TAGGING ...................................................................................... 12 Bull Trout Sampling ............................................................................................................... 12 Bull Trout Tagging ................................................................................................................. 14 MONITORING BULL TROUT MOVEMENTS ................................................................................... 15 Acoustic Tag Monitoring ....................................................................................................... 15 PIT Tag Monitoring ............................................................................................................... 17 BULL TROUT HABITAT USE IN THE MAINSTEM COLUMBIA RIVER ............................................. 17 RESULTS ..................................................................................................................................... 18 BULL TROUT SAMPLING AND TAGGING ...................................................................................... 18 Bull Trout Sampling ............................................................................................................... 18 Bull Trout Tagging ................................................................................................................. 21 MONITORING BULL TROUT MOVEMENTS ................................................................................... 22 Acoustic Tag Monitoring ....................................................................................................... 22 PIT Tag Monitoring ............................................................................................................... 26 BULL TROUT HABITAT USE IN THE MAINSTEM COLUMBIA RIVER ............................................. 29 DISCUSSION ............................................................................................................................... 30 BULL TROUT SAMPLING AND TAGGING ...................................................................................... 31 MONITORING BULL TROUT MOVEMENTS ................................................................................... 32 Acoustic Tag Monitoring ....................................................................................................... 33 PIT Tag Monitoring ............................................................................................................... 34 Use of the Mainstem Columbia River by Walla Walla Basin Bull Trout-Final 2011 Annual Report 5 HABITAT USE OF ACOUSTIC TAGGED BULL TROUT ................................................................... 36 SUMMARY .................................................................................................................................. 37 PLANS FOR FY2012 ................................................................................................................... 37 REFERENCES ............................................................................................................................. 39 APPENDIX A ............................................................................................................................... 43 APPENDIX B ............................................................................................................................... 44 APPENDIX C ............................................................................................................................... 50 Use of the Mainstem Columbia River by Walla Walla Basin Bull Trout-Final 2011 Annual Report