1. Gulf of Alaska Climate and Oceanography

2. Pacific Decadal Oscillation positive phase negative phase tao.atmos.washington.edu/pdo/ Winter PDO score (November – March) jisao.washington.edu/pdo/PDO.latest

3. Pacific Decadal Oscillation Oceanographic correlates: - Atmospheric pressure- Air / sea temperature - Freshwater input- Surface salinity - Mixed layer depth- Upwelling / downwelling strength - Wind stress- Sea ice extent / time of thaw - Nutrient flux- Current strength / gyre circulation - Solar radiation absorption- Aerosol (dimethylsulfide) production - Primary productivity- Secondary productivity

4. Pacific Decadal Oscillation Effect on trophic level of Alaska’s commercial fishery landings 1964-2003

5. Pacific Decadal Oscillation Mantua et al. 1997, Minobe 1997 PDO journal articles listed in Web of Science

6. -3.0 -2.0 0.0 1.0 2.0 195019601970198019902000 Victoria Pattern score Principal component 2 - Victoria Pattern (Bond et al. 2003. Geophys. Res. Let. 30:2183) jisao.washington.edu/pdo/PDO.latest

7. (Rodionov. 2004. Geophys. Res. Let. 31:L09204) Community state (NMDS axis1) P < 0.0001 P > 0.1 More groundfish More capelin & shrimp Catch composition of small-mesh trawls in three Alaska Peninsula Bays July – October hauls; Chignik-Castle, Kuiukta, Pavlof Bays

8. Winter PDO score (November – March) Temperature anomaly relative to 1961-1990 (ºC) Average global temperature East Anglia University, UK www.cru.uea.ac.uk/cru/data/temperature/#datdow jisao.washington.edu/pdo/PDO.latest East Anglia University, UK www.cru.uea.ac.uk/cru/data/temperature/#datdow Temperature anomaly relative to 1961-1990 (ºC) Average North Pacific temperature

9. hour month day yearcenturydecademillennium Time scale of data collection Overview: GOA Climate and Oceanography Posters Early Holocene / Late Pleistocene Shoreline North of the Present Ice Margin of the Bering Sea, A. Pasch & N. Foster Nutrient Dynamics in the Gulf of Alaska, C. Mordy et al. GEM Biophysical Observations Aboard the Alaskan State Ferries, E. Cokelet et al. A Catalog of Marine Gap Winds for the Western and Northern Gulf of Alaska, J. Curtis & N. Bond Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska, M. Janout et al. Oceanographic Boundary Conditions to Cook Inlet, W. Pegau et al.

10. A Catalog of Marine Gap Winds for the Western and Northern Gulf of Alaska Joel Curtis and Nicholas Bond

11. Oceanographic Boundary Conditions to Cook Inlet W. Scott Pegau, Edward Cokelet and Susan Saupe

12. Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska Markus Janout, S. Okkonen, T. Weingartner, D. Musgrave, and T. Royer surface salinity sea surface height bathymetry

13. Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska Markus Janout, S. Okkonen, T. Weingartner, D. Musgrave, and T. Royer

14. Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska Markus Janout, S. Okkonen, T. Weingartner, D. Musgrave, and T. Royer

15. GEM Biophysical Observations Aboard the Alaskan State Ferry Tustumena Edward Cokelet, A. J. Jenkins, W. S. Pegau, C. W. Mordy, and M. Sullivan

16. GEM Biophysical Observations Aboard the Alaskan State Ferry Tustumena Edward Cokelet, A. J. Jenkins, W. S. Pegau, C. W. Mordy, and M. Sullivan

17. Nutrient Dynamics in the Gulf of Alaska Calvin Mordy, Peter Proctor, Sigrid Salo, Phyllis J. Stabeno, and David P. Wisegarver

18. Invertebrate Evidence for an Early Holocene / Late Pleistocene Shoreline North of the Present Ice Margin of the Bering Glacier Anne D. Pasch and Nora R. Foster

20. Mike Litzow 1 & Lorenzo Ciannelli 2 1 Alaska Fisheries Science Center, NOAA Fisheries 2 Center for Ecological and Evolutionary Synthesis, University of Oslo Has Climate Change Produced Oscillating Ecosystem Control in the Gulf of Alaska?

21. Taxa involved in PDO-driven community reorganizations SalmonShrimp Zooplankton Gadids Flatfishes CapelinJellyfish Seabird / pinniped diets SalmonAnchovies Zooplankton Sardines MackerelHake RockfishSablefish Seabirds Tuna Sardines Anchoveta Seabirds Sardines Anchovies Zooplankton Tuna

22. PDO regime shift and Gulf of Alaska cod abundance Estimated age 3+ biomass 76/77 regime shift 10 3 metric tons Average of models 2 & 3, 2006 SAFE document Cold regime 1954 - 1975 Proportion of occurrence in NMFS bottom trawls Warm regime 1978 - 2005 Proportion of hauls with cod

23. CPUE (kg / km towed) Pavlof Bay small-mesh trawl data July – October, n = 593 hauls

24. Cod exercise top-down control on shrimp populations in N. Atlantic (Worm and Myers 2003. Ecology 84:162-173) Cod-shrimp interactions Cod regulation cascades to zooplankton, phytoplankton and nutrients (Frank et al. 2005. Science 308:1621-1623)

25. Climate effects on cod-shrimp interactions N. Pacific biological time series show non- linear dynamics / alternate stable states (Hsieh et al. 2005. Nature 435:336-340) Alternate stable states predict different ecological controls under different climate regimes – i.e., oscillating control (Scheffer et al. 2001. Nature 413:591-596)

26. Oscillating control hypothesis: Approach: 1) Cod-shrimp abundance correlations negative correlation = top down control positive or weak correlation = bottom-up control (Worm and Myers 2003. Ecology 84:162-173) multi-modal distribution of controlling parameters necessary condition of alternate states (Scheffer et al. 2001. Nature 413:591-596) 1970s climate regime shift resulted in change between bottom-up and top-down control in Gulf of Alaska cod-shrimp system Approach: 2) Non-additive modeling approach to test for different control under different climate regimes (Cianelli et al. 2004. Ecology 85:3418-3427, Cianelli et al. 2005. Proc. R. Soc B 272:1735-1743)

27. Climate regulation of top-down and bottom-up ecosystem control Correlation strength (running 5-yr Pearson’s r) Temperature index (PC1 score) 1 0 01 -2 74 75 76 77 78 79 80 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 81 Top-down control Bottom-up control Temperature effects on running 5-yr correlation between cod and standardized prey abundance (capelin and 4 shrimp species) Model R 2 = 0.42, P(temperature) = 0.005 Count 1) Correlation approach

28. Non-additive modeling approach Selects between competing models: Generalized Additive Model (GAM): response variable estimated by adding effects of smoothing functions for each explanatory variable Nonadditive model: constructs separate GAMs for data below and above threshold value in some environmental or biological parameter Choice of additive or non-additive model, and selection of threshold value, made by minimizing # of parameters and maximizing model fit to data

29. Prey abundance index P = 0.01 Temperature index (PC1 score) P = 0.03 Effect on cod abundance Log (cod CPUE) lag 1 yr P < 0.001 Additive model of cod abundance Model R 2 = 0.74 2) Non-additive modeling approach

30. Log (cod CPUE) Effect on pink shrimp abundance P = 0.003 Below threshold Temperature (PC1 score) Effect on pink shrimp abundance Above threshold P = 0.08 Non-additive factors affecting pink shrimp abundance Community state (NMDS axis 1) More shrimp & capelin More groundfish Threshold Model R 2 = 0.85 2) Non-additive modeling approach

31. Conclusions 1) Support for hypothesis that climate change has produced oscillating control in Gulf of Alaska – shifts between bottom-up and top-down control - temperature regulation of top-down and bottom-up control of cod-shrimp interactions - non-additive control of shrimp populations, depending on community state 2) Results demonstrate limitations in using annual-scale variability to study decadal-scale patterns in climate-ecosystem interactions

32. Acknowledgements Paul Anderson, Dave Jackson, Alisa Abookire, Franz Mueter and everyone who helped collect small-mesh trawl data through the years…