1. Steelhead Trout Production Studies at Sitkoh Creek, Southeast Alaska, 2003 – 2007 PIT-tagging, digital scale imaging/ageing & brood-tables March 2008 Pacific Coast Steelhead Management Meeting, Boise Idaho Alaska Department of Fish and GameDivision of Sport Fish Research funded by Federal Aid in Sport Fish Restoration Act (16 U.S.C. 777-777K ) under Projects F-10-18 and 20, Job R-1-9. Dave Love

2. Figure 2. Location of the weir site on Sitkoh Creek.

3. Objectives Adult steelhead & steelhead smolts: counts, PIT tagging, ASL Adult steelhead & steelhead smolts: counts, PIT tagging, ASL Steelhead parr: minnow trapping for age and length data Steelhead parr: minnow trapping for age and length data Cutthroat, rainbow trout and Dolly Varden char: Cutthroat, rainbow trout and Dolly Varden char: counts, length frequencies Sitkoh Ck Project- objectives and goals Goal: Define minimum # to fully seed habitat Smolt per spawner index, brood-table reconstruction Smolt per spawner index, brood-table reconstruction Smolt per useable habitat estimate – habitat project Smolt per useable habitat estimate – habitat project Expansion factor estimates - snorkel surveys Expansion factor estimates - snorkel surveys

4. Sitkoh Ck - upstream and downstream traps

5. Sitkoh Ck Project - PIT tagging

7. Sitkoh Creek Weir – counts, sex ratios, lengths 1,691 2) 3,5612,2303,7423,166# downstream SMOLT EMIGRATION 249556Number untagged 82%76%67%73%68% survival to kelt 345292363555460# downstream ADULT EMIGRATION 66%65%67%61%62% Female 34%35%33%39%38% Male 465-915548-923550 - 935576 - 930555 - 910Length range (mm FL) 742749753740751Mean length (mm FL) 422 1) 395538758672# upstream ADULT IMMIGRATION 20072006200520042003 Sample year 1) Peterson estimate & Chapman’s modification, range 408-437, SE(N)=7.3 2) maybe an incomplete count, due to cold spring water temps, early weir removal

8. Sitkoh Ck Project – digital scale imaging Screen Scan Microfiche & ScanPro software Leica DMD108 electronic microscope

9. Sitkoh Ck Project- freshwater scale ageing Develop method based on common scale characteristics Develop method based on common scale characteristics Sitkoh Ck = spring spawning life-history Sitkoh Ck = spring spawning life-history Freshwater and marine components to scale Freshwater and marine components to scale Known ocean ages from PIT tagging Known ocean ages from PIT tagging Electronic images made & archived Electronic images made & archived Freshwater ages –triplicate reads, multiple readers, read repeatability, paired scale & otolith comparisons Freshwater ages –triplicate reads, multiple readers, read repeatability, paired scale & otolith comparisons

10. Sitkoh Project- freshwater scale ageing 91.398.391.391.9 % repeatability 8.71.78.78.1% not ageable 8.11.28.78.1NGS 0.6 No match 2.30.64.12.3age 6 8.79.314.09.9age 5 58.162.254.150.6age 4 22.126.219.229.1age 3 %%FW scale ages Final read comparisons All readers reader 3reader 2reader 12007 Age Difference Plots indicate no bias between readers, Avg Percent Error (APEj) of 4.4% and CVj(APE) of 5.8% indicate relative precision of age estimates from: Campana, et al., 1995. Graphical and statistical methods for determining the consistency of age determinations. Trans. Amer. Fish. Soc. 124: 131-138

11. Sitkoh Project- freshwater scale ageing 2003 brood year = 1.4 smolt per spawner (each years’ FW age) 2.6 smolt per spawner (using average FW Age) 0.030.120.470.270.012878559averages 0.020.090.580.220.00 1,691*4222007 0.120.210.370.030.00 3,5613862006 0.010.150.580.240.00 2,2305382005 0.000.060.400.480.02 3,7427642004 0.010.110.400.380.04 3,1666792003 Age 6Age 5Age 4Age 3 Age 2 Smolt Production Adult EscapementYear * maybe an incomplete count, due to cold spring water temps, early weir removal

12. Sitkoh Ck Project - 2007 PIT-tagged smolt returns Tag failure (4 tags) 1 ocean 2 ocean 3 ocean / 1 repeat Total tagged smolt 2 ocean / 1 repeat 3 ocean 2 ocean / 1 skip / 1 repeat 4 ocean 0.9% 0.2 18.2 4.7 63.3% 3.1 33.2 0.5 2.4 % return in 2007 OCEAN AGES 2005 smolts 18.2% (77) 2006 smolts 0.02% (1) 2004 smolts 36.3% (153) 2003 smolts 7.6% (32)

13. Sitkoh Ck Project- Adult scale ageing Adult scale ageing Adult scale ageing Sitkoh Ck known ocean-ages as proxy/ageing validation Sitkoh Ck known ocean-ages as proxy/ageing validation Useful for other SE Alaska projects needing scale ages Useful for other SE Alaska projects needing scale ages Prelim. accuracy estimate 2006 recaps (n=152) 2006 recaps (n=152) 1 scale aging technician 1 scale aging technician Triplicate reads of each scale, 2 of 3 reads matching Triplicate reads of each scale, 2 of 3 reads matching 17.8% no match 17.8% no match 83.1% correct compared to known ocean ages of returning smolts 83.1% correct compared to known ocean ages of returning smolts Need 2 addnl triplicate reads & recaps in 2007 Need 2 addnl triplicate reads & recaps in 2007

14. For the 2003-2007 period: Adult escapement:395 – 758 (65% female) Adult escapement:395 – 758 (65% female) Smolt outmigration: 1,691 and 3,742 Smolt outmigration: 1,691 and 3,742 Survival following spawn: 75% Survival following spawn: 75% PIT tagging success: 76% of run in 2007 PIT tagging success: 76% of run in 2007 Scale ageing estimates: Scale ageing estimates: FW methods repeatable, but maybe biased FW methods repeatable, but maybe biased SW methods repeatable and accurate SW methods repeatable and accurate smolts per spawner:1.4 to 2.6 smolts per spawner:1.4 to 2.6 adults to adults:91 adults from 2003 adults adults to adults:91 adults from 2003 adults (2-freshwater, 2-ocean based on scale ageing) Sitkoh Ck weir Project- conclusions

15. Questions?

16. Funding for this project came from the U.S. Fish and Wildlife Service’s Federal Aid in Sport Fish Restoration Act, with matching funds coming from the State of Alaska’s Fish and Game Fund. We would also like to acknowledge the following staff: Bob Chadwick, Dale Brandenburger, Lee Close, Dirk Middleton, Rich Didrickson, Rob Pettett, Anthony Crupi, Peter Bangs, Kurt Kondzela, Carol Coyle, Randy Mullen, Judy Lum, Carrie Hoover, Jennifer Stahl, Troy Tydingco, Heather Riggs, Jason Shull, Keith Pahlke, Rocky Holmes, Brian, Frenette, Dick Callahan, Alex Blaine, Brian Glynn, Jeff Nichols, Jason Haas, Jarrod Sowa, Shawn Johnson, Kercia Schroeder, Monica Matz, Tom Brookover, Kevin Brownlee, Mark Schwan, Christine Schmale, David Gregovich, Doug Fleming. Also thanks to Roger Harding, John Der Hovanisian, Mark Schwan, Dan Reed, and Randall Mullen who provided planning, analytical and editorial support. Acknowledgements