An exploratory analysis of climate impacts on Washington steelhead productivity

1. An exploratory analysis of climate impacts on Washington steelhead productivity Nate Mantua University of Washington Climate Impacts Group Pacific States Marine Fisheries Commission Pacific Coast Steelhead Meeting March 7-9, 2006 Fort Worden, WA

2. Analysis • Compare steelhead environment for “best” and “worst”productivity periods from select populations • Use daily streamflow, ocean temperatures, and upwelling indices during key periods of steelhead lifecycle

3. Data • WDFW steelhead data • Estimate recruits-per-spawner (R/S) indices from WDFW run-reconstructions by assuming a fixed age-structure • Hatchery smolt-to-adult return rates (SARs) • Environmental data • Daily streamflow from USGS gages • Sea surface temperatures: time series from select locations + maps from ship-buoy-satellite data • Annual spring transition dates

4. Populations discussed in this talk Skagit R. wild WSH Quileute R. wild WSH Wenatchee R. Wild SSH Green R. hatchery WSH Yakima R. Wild SSH Chehalis R. WSH (hatchery and wild) Kalama R. WSH (hatchery and wild)

5. Wenatchee R. SSH run-size and R/S • The Wenatchee R. summer steelhead declined dramatically in the 1960s-70s, rebounded in early 1980s, down in the 1990s, and sharply increased in 1999-2001

6. Wenatchee R. water year flow anomalies: (1971-2000 averages) Standardized anomalies

7. Annual Run-Sizes Population and productivity trends for Yakima R. are similar to those for Wenatchee R. • What’s driving these fluctuations? • Was it the ocean? Streamflow? Both? Neither? Annual R/S

8. Age .0 (post-smolt) cpue (from Burgner et al 1992, INPFC)

9. 3rd year 4th year Nearshore SSTs during Wenatchee summer-run ages 3 and 4 • There is a weak tendency for 1st spring/summer SSTs to be warm during best S/R years, and cool during the worst S/R years • This is also true in 1st and 2nd winter at sea Smolt migration

10. Seasonal temperature and all-ages steelhead distribution patterns (after Burgner et al 1992, INPFC) April-May-June July-August-September January-February-March October-November-December

11. Spring/Summer smolt-year SST and Wenatchee R. SSH R/S extremes 1980 1981 1982 1984 1998 1971 1972 1987 1989 1991

12. fall/winter smolt-year SST and Wenatchee R. SSH R/S extremes 80-81 81-82 82-83 84-85 98-99 71-72 72-73 87-88 89-90 91-92

13. April 1st SW WA hatchery steelhead SARs • Kalama and Chehalis R. hatchery winter-run SARs are similar • warm spring-summer SSTs have no high values • latest spring transition dates have low SAR rates

14. Spring/Summer smolt-year SST and Chehalis hatchery SAR extremes 1983 1984 2000 2001 2002 1982 1989 1993 1996 1997

15. April 1st Green R. Hatchery SARs • Green R. hatchery winter-run SARs show a prolonged downward slide • tendency for the warmest spring-summer SSTs to have only low values • Weak tendency for late spring transition dates to have low values

16. Quileute R. wild winter-runs • Peak run-sizes from 1995-2001, lows from 1994-2003 • R/S highest from 1991-94 during period of relatively low escapements

17. 3rd year 4th year Nearshore SSTs during Quileute winter-run ages 3 and 4 There is a weak tendency for 1st spring/summer SSTs to be warm during best S/R years, and cool during the worst S/R years This is also true in 2nd summer at sea Smolt migration

18. Skagit R. wild winter-runs • Peak run-sizes from 1985-1990, lows from 1978-1981 and 1991-1998 • R/S highest from 1978-84 during period of relatively low escapements

19. 1st year 2nd year Skagit winter-run age 0-2 streamflow and age 2-4 nearshore SSTs weak tendency for high summer flows in emergence year of high R/S year, and high winter flows for low R/S years weak tendency for SSTs to be warm during best S/R years 3rd year 4th year Smolt migration

20. Preliminary summary • To date, this exploratory analysis finds no prominent patterns of environmental links with productivity • confounded with density dependence related to varying escapements? • Weak tendencies for high wild fish productivity (and low hatchery fish SARs) with warm spring-summer SST during smolt migration year • There are many more exploration and analysis opportunities with these data!

21. acknowledgements • thanks to the many WDFW and Tribal staff who have conducted spawner surveys over the past 30 years so that this rich run-reconstruction data set exists • Bill Gill from WDFW provided run-reconstruction data sets and advice • Curt Kraemer provided Green River hatchery SARs • Nick Gayeski for providing Skagit R. run-reconstruction data • Funding for this research has been provided by NOAA’s Regional Integrated Sciences and Assessments program as part of NOAA’s Climate Office

22. Catch per angler day as an index of abundance for BC wild steelhead Queen Charlotte Is. West Coast VI East Coast VI Lower Mainland • regional patterns suggest common environmental influences • yearly changes in CpAD modestly correlated with yearly changes in coastal upwelling (summer) and downwelling (winter) winds 2 year prior to catch data (typical year of smolt migration) … Smith and Ward, 2000, CJFAS

23. Smolt-to-adult (marine) survival: Keough River, Vancouver Island Smith and Ward 2000, CJFAS

24. spring/summer SST during BC’s good 80s and poor 60s-70s Low CpAD era: 1966-79 High CpAD era: 1981-89 A weak tendency for higher CpAD when spring/summer SSTs near average.