Climate considerations in the management of anadromous fishes in the Pacific Northwest

1. Climate considerations in the management of anadromous fishes in the Pacific Northwest Nate Mantua JISAO Climate Impacts Group University of Washington NOAA Climate and Living Marine Resources Workshop Pacific Marine Environmental Lab May 14, 2008 Seattle, WA

2. Outline • A bit of background • Short term harvest planning • Long-term recovery planning • Water resources and hatchery operations

3. The Ocean Phase: most of a salmon’s life, typically half the mortality, and nearly all the growth

4. Salmon hatcheries - not to be confused with fish farms

5. Abundance varies • Salmon fisheries are managed at the level of stocks (or independent population groups) • Stock-sizes vary, so the success of abundance-based management depends in part on accurate pre-season run-size forecasts • and accurate stock distribution forecasts for mixed stock fisheries

6. The abundance of Pacific salmon has likely been at historic highs since the 1980s • Hatcheries have contributed ~60% of the increase • The ocean’s carrying capacity for salmon appears to have doubled! From Nathan Taylor UBC Fisheries Centre Millions of adults

7. A North-South see-saw in salmon production spring chinook returns to the Columbia River mouth (1000s) Alaska pink and sockeye catch (millions) Cool PDO Warm PDO Cool PDO Warm PDO ???

8. These are hard times for west coast salmon and salmon fisheries • Wild salmon abundance now just a few percent of historic levels, and hatchery programs have only partially mitigated for the lost abundance • 1990s ushered in the era of ESA listings • 28 of 52 west coast ESUs currently listed as either threatened or endangered with extinction under the ESA • 1990s also ushered in an era of sharply reduced harvest opportunities for west coast salmon fishers

9. Klamath River fish kill 2002 • Disease, high fish densities, low flows and a very warm river resulted in massive kill of adult chinook salmon in the lower Klamath River Conservation concerns over the offspring from the 2002 returns led to a curtailed CA/OR chinook season in 2005, and sharp restrictions in 2006 www.oregonwild.org

11. Forecasts for short-term (3-6 month) harvest and allocation planning • pre-season run-size predictions for every river: “how many fish will there be in the ocean this summer fishing season? Whose fish are they? How much protection do depleted stocks need?” • run-size forecasts are based on assumptions about productivity trends (typically a persistence forecast) and information about the number of spawning adults, jack returns, and juveniles produced in hatcheries … use fish to predict fish, yet forecast errors are frequently 50-100%! • No climate information has been formally used, but many studies have looked to “climate indicators” for help in reducing forecast errors

12. Oregon (OPI) coho marine survival Persistence forecasts often fail because productivity varies by an order of magnitude…

13. West-coast sub-arctic habitat is dynamic and sensitive to changing wind patterns (frequently influenced by El Niño and La Niña) Sept 1997 El Niño Sept 1998 La Niña

14. upwelling food webs in our coastal ocean: the California Current Cool water, weak stratification high nutrients, a productive “subarctic” food-chain with abundant forage fish and few warm water predators Warm stratified ocean, few nutrients, low productivity “subtropical” zooplankton, a lack of forage fish and abundant predators Typically high NW salmon survival Typically low NW salmon survival

15. coastal ocean impacts on coho marine survival (Logerwell et al. 2003, Fish. Oceanogr.) • key factors? • Stratification • spring transition date • spring winds, upwelling and transport • key factors? • Stratification • winter winds, downwelling and transport ? ? 1st winter at sea 1st spring at sea A few to ~100 adults in 2nd summer 10’s to 100’s post-smolts early summer 1000 juvenile Salmon (smolts)

16. 4 index Ocean Conditions Model “hindcasts” for OPI coho marine survival, 1969-1998 Logerwell et al. 2003, Fish. Oc. Empirically based models often do a good job “explaining” the past with environmental factors, but errors are generally large in forecast mode R2= .75

17. Fall Winter Spring Summer “fish-based forecasts” Jack returns Harvest & allocation decisions(February-March) Fishery Run-size forecast (using SST forecast) Run-size forecast (using obs’d ocean conditions) Coho Forecasting Systems Oregon coho salmon survival Coastal Ocean Conditions Sea surface temperatures Sea level Nearshore winds Plankton surveys http://www.cses.washington.edu/cig/fpt/orcohofc.shtml

18. Lessons learned • Time and space scale of climate information provided must match the scale of management decisions in order to be useful • Our basin-scale research results were inappropriate for local scale management decisions • Collaborating with a fishery scientist charged with supplying pre-season salmon predictions solved our scale mis-match problem • A better understanding for the complexity of the climate impacts on salmon pathway allowed for a sobering assessment of predictability limits • Key aspects of ocean conditions for coho salmon are not likely predictable, and this result highlights the importance of monitoring

19. Monitoring Systems http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/a-ecinhome.cfm

20. Multi-year to decadal forecasts • Skillful forecasts for the PDO or other modes of Pacific Decadal Variability are of great interest to salmon fisheries • It is now widely known that climate matters for Pacific salmon, but the lack of skillful forecasts limits the utility of this information

21. The longer view: salmon recovery and restoration planning • Will climate change derail well-intended plans? • NOAA Fisheries is crafting recovery plans and criteria for getting ESA-listed stocks delisted • Biological Opinions are crafted to guide water management operations so they comply with ESA mandates in major salmon producing watersheds like the Columbia, Klamath, and Sacramento River basins • Large-scale conservation planning in the NGO world seeks advice on where to invest effort and $ • Federal, state, and local agencies are looking for guidance on how and where to invest efforts to protect and restore salmon • Watershed-scale salmon restoration efforts are widespread across the west

22. Snohomish R. Chinook Recovery Planning Case Study Snohomish R. • Evaluate the benefits of alternative habitat restoration plans under different future climate scenarios using linked hydrologic and salmon-lifecycle models • Battin et al. 2007: PNAS

23. Impacts of Climate Change on Salmon Recovery in the Snohomish River (Battin et al. 2007: PNAS) Decreasing Spawning Flows • Climate Change will make • salmon restoration more difficult: • Decreasing Summer Low Flows • Increasing Winter Peak Flows • Increasing water temperatures in critical periods Increasing Winter Flows

24. Additional climate considerations for NW salmon management • Water management • In all anadromous river basins, operations seek to balance multiple demands on water supplies; “normative” in-stream flows are the primary goal to optimize salmon production, but this usually conflicts with hydropower, irrigation, flood control, and transportation goals • Hatchery operations: the NW has enormous investments in this infrastructure, and hatcheries are now the backbone of west coast salmon fisheries. • Hatchery operations make no allowance for climate considerations • Climate information has the potential to inform decisions on smolt release number and timing, facilities siting, mothballing failing programs, or building new ones…