1. ESA-listed Snake River Salmon: What’s the link to Snake River dams? John G. Williams NOAA Northwest Fisheries Science Center Seattle john.g.williams@noaa.gov Conference on Large Scale Water Infrastructure: GLOBAL PERSPECTIVES ON LARGE DAMS 3-5 November 2006 - New Haven, Connecticut, USA

2. Poll

3. Snake River dams or salmon Can we have both?

4. Decision makers need to know --- Is dam removal necessary?

5. Decision makers need to know --- Is dam removal necessary? Is dam removal sufficient?

6. Salmon stocks pre- and post dam construction Direct dam impacts Modifications to dams Where are we now? Can we answer the questions? Road Map

13. No data

14. Changes to the hydropower system

15. Improvements or installation of juvenile bypass systems at dams

16. Transportation by barge

17. Changes in water storage

18. Changes in turbine operations

19. Spill designated for fish

21. Columbia River salmon ESUs (13 of 17 listed under the U.S. Endangered Species Act) Snake River – Sockeye Salmon - Sockeye Salmon Chinook salmon - spring-summer run; fall-run Steelhead - Steelhead Columbia River – Sockeye Salmon - Lake Wenatchee/Okanogan River Chinook salmon - Upper spring-run, Upper summer-fall run, Middle spring-run, Deschutes River summer-fall run, Lower Steelhead - Upper, Middle, and Lower Coho salmon - Lower Chum salmon - Lower Upper Willamette River - Chinook salmon; Steelhead

23. Other significant changes

31. Context Stocks naturally fluctuate

32. Baumgartner et al. 1992 CalCofi

33. Schindler et al. 2006 CJFAS

34. Chance (1973) - information from early pioneer diaries: In 1811 and in the late 1820s the middle Columbia River (between the confluence of the Snake River and Kettle Falls) had salmon populations so low that settlers and Native Americans relied on horseflesh for survival

35. Scheuerell and Williams 2005 Fisheries Oceanography R 2 =0.71

39. Do dams effect fish?

40. Could we harvest adults at higher rates without dams?

41. Do dams effect fish? Could we harvest adults at higher rates without dams? Is recovery limited by dams?

42. If the evidence was clear, the debate would not rage