Fishery Data Series No. 99-17 Escapements of Chinook Salmon in Southeast Alaska and Transboundary Rivers in 1998 by Keith A. Pahlke August 1999 Alaska Department of Fish and Game Division of Sport Fish FISHERY DATA SERIES NO. 99-17 ESCAPEMENTS OF CHINOOK SALMON IN SOUTHEAST ALASKA AND TRANSBOUNDARY RIVERS IN 1998 by Keith A. Pahlke Division of Sport Fish, Douglas Alaska Department of Fish and Game Division of Sport Fish P. O. Box 240020 Douglas, AK 99824-0020 August 1999 Development and publication of this manuscript were partially financed by the Federal Aid in Sport Fish Restoration Act (16 U.S.C. 777-777K ) under Project F-10-14, Job No. S-1-6. The Fishery Data Series was established in 1987 for the publication of technically oriented results for a single project or group of closely related projects. Fishery Data Series reports are intended for fishery and other technical professionals. Distribution is to state and local publication distribution centers, libraries and individuals and, on request, to other libraries, agencies, and individuals. This publication has undergone editorial and peer review. Keith A. Pahlke Alaska Department of Fish and Game, Division of Sport Fish P. O. Box 240020, Douglas, AK 99824-0020, USA This document should be cited as: Pahlke, Keith A. 1999. Escapements of chinook salmon in Southeast Alaska and transboundary rivers in 1998. Alaska Department of Fish and Game, Fishery Data Series No. 99-17, Anchorage. The Alaska Department of Fish and Game administers all programs and activities free from discrimination on the basis of sex, color, race, religion, national origin, age, marital status, pregnancy, parenthood, or disability. For information on alternative formats available for this and other department publications, contact the department ADA Coordinator at (voice) 907-465-4120, or (telecommunication device for the deaf) 1-800-478-3648. TABLE OF CONTENTS Page LIST OF TABLES.......................................................................................................................................................ii LIST OF FIGURES.....................................................................................................................................................ii LIST OF APPENDICES..............................................................................................................................................ii ABSTRACT ................................................................................................................................................................ 1 INTRODUCTION....................................................................................................................................................... 1 Description of study sites...................................................................................................................................... 3 METHODS.................................................................................................................................................................. 5 Escapement goals ................................................................................................................................................. 5 Indices of escapement........................................................................................................................................... 6 RESULTS.................................................................................................................................................................... 7 Taku River............................................................................................................................................................ 8 Stikine River....................................................................................................................................................... 11 Andrew Creek..................................................................................................................................................... 12 Alsek River......................................................................................................................................................... 14 Unuk River ......................................................................................................................................................... 16 Chickamin River................................................................................................................................................. 16 Blossom River .................................................................................................................................................... 21 Keta River........................................................................................................................................................... 21 King Salmon River ............................................................................................................................................. 21 Situk River.......................................................................................................................................................... 21 Chilkat River ...................................................................................................................................................... 21 Other systems ..................................................................................................................................................... 26 DISCUSSION............................................................................................................................................................ 27 ACKNOWLEDGMENTS ......................................................................................................................................... 28 LITERATURE CITED.............................................................................................................................................. 28 APPENDIX A............................................................................................................................................................ 31 i LIST OF TABLES Table Page 1. Estimated escapement of chinook salmon to Southeast Alaska and transboundary rivers in 1998 .......... 8 2. Counts of spawning chinook salmon in index areas of the Taku River, 1951–1998 ................................. 9 3. Distribution of spawning chinook salmon among index areas of the Taku River during years when all index areas were surveyed ............................................................................................................. 10 4. Taku River index counts and mark-recapture estimates of escapement........................................................... 11 5. Counts of spawning chinook salmon in index areas of the Stikine River, 1975–1998 ..............................11 6. Comparison of peak aerial survey counts of chinook salmon to final counts at the Little Tahltan River weir, 1985–1998................................................................................................................................... 12 7. Counts of spawning chinook salmon in selected rivers in central Southeast Alaska, 1956–1998.................... 13 8. Escapement of chinook salmon to the Klukshu River and counts of spawning adults in other tributaries of the Alsek River, 1962–1998 .................................................................................................... 15 9. Peak escapement counts of chinook salmon to index areas of the Unuk River, 1960–1998............................ 17 10. Distribution of spawning chinook salmon among index areas of the Unuk River for years when all index areas were surveyed.................................................................................................................................18 11. Counts of chinook salmon in index areas of the Chickamin River, 1960–1998............................................... 19 12. Distribution of spawning chinook salmon among index areas of the Chickamin River for years when all index areas were surveyed ...........................................................................................................................20 13. Counts of chinook salmon for selected rivers in Behm Canal, 1948–1998...................................................... 22 14. Peak escapement counts and weir counts of spawning chinook salmon in the King Salmon River, 1957–1998..... 24 15. Harvest, escapement, and minimum total run of Situk River chinook salmon, 1976–1998 ............................. 26 LIST OF FIGURES Figure Page 1. Map showing location of selected chinook salmon systems in Southeast Alaska, Yakutat, and transboundary rivers .......................................................................................................................... 2 2. Counts of chinook salmon in index areas of the Taku River, 1975–1998........................................................ 10 3. Counts of chinook salmon at the Little Tahltan River weir, Stikine River, 1975–1998.................................. 12 4. Counts of chinook salmon at Andrew Creek weir (1976–1984) and in aerial/foot surveys, 1975, 1985–1998 ..... 14 5. Escapement of chinook salmon to the Klukshu River tributary of the Alsek River, 1975–1998 ..................... 16 6. Counts of large chinook salmon in index areas of the Unuk River, 1975–1998 ...............................................18