1. The Bering Sea Is it just a Warmer Barents Sea? George L. Hunt, Jr. University of California, Irvine and Bernard Megrey NOAA Alaska Fisheries Science Center

2. Contents Physical Comparison Climate and Advective Processes Productivity Biomass Ecosystem Structure

3. P. Stabeno, PMEL The Bering Sea

4. The Barents Sea °C H. Loeng & G. Ottersen

5. Bering & Barents Seas: Physical Parameter SE Bering Sea Barents Sea Latitude54-60 °N68-85 °N Area > 200m (km 2 )21.1 x 10 3 533.2 x 10 3 Area < 200m (km 2 ) Advection 463.4 x 10 3 ~1 Sv 472.9 x 10 3 ~4 Sv Nitrate (mM m -3 ) 10-3010 -12 Phosphate (mM m -3 ) 1.0-2.0 0.85 Silicate (mM m -3 ) 25-606-8 Data from: Dommasnes et al., 2001; Sakshaug and Walsh, 2000; Aydin et al., 2002; ACIA, In Press

6. Lower Trophic Level Productivity Bering SeaBarents Sea InnerMiddleOuterArcticAtlantic Tot. Primary Production (g C m -2 y -1 ) 50-70 150-175 160<90 <200 New Prod.<20 30-50 ?<40 70-110 Secondary Production 2-6 8-30 16-501-18 3-17 Dom. Taxa DiatomsPhaeocystis Sakshaug & Walsh 2000

8. Arctic Oscillation and Pacific Decadal Oscillation Indices J. Overland, PMEL

9. Bering Sea: Decadal-Scale Surface Advection Wilderbuer et al., 2002

10. Bering Sea Flatfish Recruitment as a Function of Destination of Larval Drift Wilderbuer et al. 2002

11. North Atlantic Oscillation Index

12. AbundanceLow MediumHigh Cold years35% 7% 1% Warm years31%14%12% Year-class Abundance of Cod H. Loeng & G. Ottersen

13. Bering and Barents Seas- Biomass (tonnes km -2 ) TaxonBarents 1990 high capelin Barents 1995 low capelin E. Bering Sea 1980s Phytoplankton Crust. Zoops. 20 58 20 58 11.8 26 Capelin Herring 4.17 1.34 0.14 3.33 - 0.78 Benthic Crust. 1.43 1.38 > 2.2 Flatfish 1.1 11.3 Gadids 1.2 2.6 35.9 Pinnipeds 0.87 0.22 Whales 0.20 0.26 Blanchard et al., 2002; Aydin et al., 2002

14. Productivity: Bering & Barents Seas Bering SeaBarents Sea Taxon P/B (y -1 ) P P Phytoplankton 1702000 117.731765 Copepods 6 330 10 500 Large Zoops 5.5 242 4 67.5 Forage Fish Herring 0.8 1 - 0.78 1 0.38 1.13 1.24 Ad Pollock/ Atlantic Cod 0.5 13.73 1.2 0.54 Small Flatfish 0.4 3.67 1 0.7 Benthic Infauna 1.3763.84 1.5 99 Aydin et al., 2002; Blanchard et al., 2002

15. Barents Sea: Zooplankton Biomass (g m -2 ) vs. Capelin Biomass (tonnes) ICES CM 2003/AFCM:22

16. Barents Sea Model Region Blanchard et al., 2002

18. Summary Why does the Bering have a pollock biomass 30X that of cod in the Barents? Nutrients & Primary Prod similar Bering -Diatoms, Barents- Phaeocystis (Sakshaug & Walsh) Bering & Barents Sensitive to Timing of Bloom Zooplankton more abundant and productive in Bering

19. Pollock eat zooplankton- lower trophic level (3.3 vs 4.3) Forage fish essential for cod; More (capelin) in Barents; Pollock cannibalistic- do not need forage fish Pollock 25X more productive More seals in Barents Sea Summary Why does the Bering have a pollock biomass 30X that of cod in the Barents?

20. 1 st ANNOUNCEMENT International GLOBEC Symposium Climate Variability and Sub-Arctic Marine Ecosystems Victoria, B.C. Canada May 16-20, 2005 Co-sponsors: Fisheries and Oceans Canada National Science Foundation, U.S.A. North Pacific Marine Science Organization (PICES) North Pacific Research Board