Tobias J. Kock Theresa L. Liedtke Dennis W. Rondorf

1. Juvenile Salmon, Dams, and Climate Change: Implications of Hydrological Alterations on Fish Passage at Dams in the Cascade Mountains Tobias J. Kock Theresa L. Liedtke Dennis W. Rondorf

2. Juvenile Salmon and Dams Year 2 Year 1 Parr • March to March • Resident behavior • Focus = growth • < 100 mm Ocean Smolts • April to August • Migratory behavior • Focus = migration, saltwater entry • 100-200 mm

3. Dam Passage Smolts (Apr-Aug) 2 3 1 • Turbine • Spillway • Collection system Ocean

4. Cowlitz Falls Dam WASHINGTON Collection Mossyrock Dam • Smolts trucked around • dams and reservoirs • Good outcome for • salmon population Mayfield Lake Riffe Lake Mayfield Dam Cowlitz Falls Dam Turbine/Spillway Passage • Smolts landlocked in • Riffe Lake • Bad outcome for salmon • population

5. Winter Dam Passage • Do coho salmon parr pass during winter? • If so, how many? • Are reservoir and river populations equally • susceptible to winter passage? Fish facility operating

6. Study Area Cowlitz River Lake Scanewa Cispus River Cowlitz FallsDam

7. Radiotelemetry study Tag Cowlitz River Monitor Lake Scanewa Fish facility operating Tag • 0.37 g • 60 d operating life • fish > 7.4 g (80 mm) Monitor Cispus River Cowlitz FallsDam = collection and release sites

8. Results 28 of 79 fish passed dam = 35% 3 of 82 fish passed dam = 4% Risk of dam passage = 19% per 1000 cfs Risk of dam passage = 49% per 1000 cfs 25 of 55 fish passed dam = 45% 49 of 128 fish passed dam = 38% 9 of 60 fish passed dam = 15% 1 of 24 fish passed dam = 4% Risk of dam passage = 75% per 1000 cfs Risk of dam passage = 9% per 1000 cfs = river released fish = reservoir released fish

9. Climate Change Predictions • Increasing temperatures = • Less snow, more rain • Streamflow timing shifts • More flow in late winter and early spring • Less flow in late spring and early summer • More winter flooding Fish facility operating

10. Cowlitz River Flows 1934, 1958, 1960, 1987, 2004 1929, 1930, 1955, 1985, 2008

11. Summary What Do We Know? What Does it Mean? • flows = coho parr movements • temperature = winter flows Earlier migration, smaller fish

12. Summary What Do We Know? What Does it Mean? • flows = coho parr movements • temperature = winter flows • 3. Earlier migration, smaller fish = • survival Earlier migration, smaller fish Increased emphasis on safe dam passage and successful collection 2,778 smolts = 100 adults 5,556 parr = 100 adults

13. Summary What Do We Know? What Does it Mean? • flows = coho parr movements • temperature = winter flows • 3. Earlier migration, smaller fish = • survival • 4. Dam passage and collection devices • target smolts Earlier migration, smaller fish Increased emphasis on safe dam passage and successful collection

14. Summary What Do We Know? What Does it Mean? • flows = coho parr movements • temperature = winter flows • 3. Earlier migration, smaller fish = • survival • 4. Dam passage and collection devices • target smolts Earlier migration, smaller fish Increased emphasis on safe dam passage and successful collection Dam passage and collection devices will need to be developed and operated to collect parr during late winter and early spring

15. Questions

16. Results • Event-time analysis • Dependent variables • Passage (yes or no) • Elapsed time to passage (d) • Independent variables • River flow (520-26,000 cfs) • Fork length (<100 mm; >100 mm) • Release site (river, reservoir) • Year (2007, 2008, 2009, 2010) • P < 0.0001 • P = 0.2062 • P < 0.0001 • P < 0.0001 River flow*year P < 0.0001