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Recruitment in Wild Smolt and Adult Steelhead Trout: the 30-year Experience at the Keogh River. Bruce R. Ward B.C. Ministry of Environment, U.B.C. And.

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Presentation on theme: "Recruitment in Wild Smolt and Adult Steelhead Trout: the 30-year Experience at the Keogh River. Bruce R. Ward B.C. Ministry of Environment, U.B.C. And."— Presentation transcript:

1 Recruitment in Wild Smolt and Adult Steelhead Trout: the 30-year Experience at the Keogh River. Bruce R. Ward B.C. Ministry of Environment, U.B.C. And Don J.F. McCubbing In-Stream Fisheries Research Inc., Vancouver, B.C. Funding Habitat Conservation Trust Fund

2 Study Location

3 Steelhead of the Keogh River

4 Trends in Adult Steelhead at the Keogh River

5 Trends in Smolt Yield at Keogh

6 Steelhead survival and abundance trends 19601965197019751980198519901995 Ocean Entry Year (t-3) 0 1 2 3 4 5 6 7 8 9 10 Oregon Marine Survival (%) 0 5 10 15 20 25 30 Keogh R Marine Survival (%) 1960-77 (6.1%) 1978-90 (3.3%) 1991-95 (0.6%) Oregon Coho Keogh Steelhead Oregon Coho & BC (Keogh) Steelhead

7 Conservation designation

8 Recruitment from the Ocean smolt-to-adult survival trend

9 Smolt-to-Adult Survival

10 Climate Change our management, policy and legal systems, plus many of our built environments may not resilient enough to cope with real present day or projected future changes in fish, salmon, and habitats that result from climate change and weather extremes. http://fisheries.c-ciarn.ca/

11 Climate Change and Steelhead El Nino/La Nina Pacific Decadal Oscillation Global Climate Change

12 Back-Calculated Smolt Length and Survival 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 14161820222426 BACK-CALCULATED SMOLT LENGTH (cm) % survival

13 Observed and Expected Survival Rates Wild Steelhead @ Keogh River

14 Tracking wild and LGB smolts in Queen Charlotte Strait

15 Post 2004/2005 Survivals SpeciesSurvival to River Mouth (%) Survival to QCS Line (%) FW survivors to QCS Line (%) Wild Steelhead smolt773140 Hatchery Steelhead smolt712942

16 Steelhead Smolt Recruitment @ Keogh

17 1990’s regime affects freshwater Freshwater capacity falls 6000 to less than 3000

18 Climate changes in freshwater as well

19 Spring migration (r 2 =0.65)

20 Steelhead Parr per meter in Treatment and Control Habitats

21 Mean length of 2-year-old (broken line, circles) and 3-year-old (solid line, squares) steelhead smolts. Open markers indicate years affected by nutrient addition. Odd- and even-year variation is attributed to Pink salmon abundance.

22 Percent composition of age 1 (grey bar), age 2 (black bar), age 3 (white bar), and age 4 (hatch bar) steelhead smolts in the Keogh River in 1996 and 1997 (no nutrient addition), and from 1998 to 2003 (nutrients added).

23 Smolts per spawner production

24 Steelhead smolt recruits Replacement at 15% Replacement at 4%

25 Recruitment in Freshwater The steelhead smolts per spawner and number of spawners in the Keogh River during the 1980s (diamonds) and the 1990s (triangles), nutrient experiments in the mid- 1980s (squares), and initial results during WRP to 2003 (circles). Our modified Beverton-Holt fit to these data (solid points) statistically distinguishes the 1980s and nutrient experiments from all other treatments, while the 1990s and initial watershed restoration treatments cannot be statistically distinguished.

26 Summary >30-yrs of study of freshwater and marine influences to variation in steelhead recruitment implicate mainly climate >30-yrs of study of freshwater and marine influences to variation in steelhead recruitment implicate mainly climate Trends in adult and smolt abundance suggest production regimes cahnges in both Trends in adult and smolt abundance suggest production regimes cahnges in both Trends in abundance and survival at Keogh are mirrored over a broad geographic area of the southern distribution, and in other species (e.g., coho) suggesting a common cause. Trends in abundance and survival at Keogh are mirrored over a broad geographic area of the southern distribution, and in other species (e.g., coho) suggesting a common cause. Mortality in the ocean duriung t he first few weeks appears high, but requires further study Mortality in the ocean duriung t he first few weeks appears high, but requires further study Productivity and capacity in freshwater is altered by nutrient dynamics, including marine-derived nutrients from Pink salmon Productivity and capacity in freshwater is altered by nutrient dynamics, including marine-derived nutrients from Pink salmon and probably habitat destruction/restoration and probably habitat destruction/restoration A highly variable riverine environment controlled by precipitation affects all steelhead life stages A highly variable riverine environment controlled by precipitation affects all steelhead life stages

27 Divine Intervention? or rather - playing God! Wild (98-02) and Wild/Living Gene Bank (2003) Steelhead Counts - Keogh River Increased adults, but….will this increase recruits?

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