1970 1980 1990 2000 0.0 0.4 0.8 Scaled abundance COMPARATIVE STUDIES AMONGST SUB-ARCTIC SEAS Ken Drinkwater ([email protected]) Institute of Marine Research and Bjerknes Center of Climate Research, Bergen, Norway ESSAS ESSAS is an IMBER regional program whose aim is to compare, quantify and predict the impact of climate variability on the productivity and sustainability of Sub-Arctic marine ecosystems. An ESSAS comparative study between different Sub-Arctic Ecosystems is testing the hypothesis that gadoids control invertebrate abundance through predation. N Investigating Invertebrate-Gadoid Interactions C. Morel West Greenland: Wieland et al. Japanese Waters: Yamamura and Sakurai 1970 1975 1980 1985 1990 1995 2000 2005 2010 Catch ('000t) 0 50 100 150 Atlantic cod 1 offshore inshore / coastal Northern shrimp 2 offshore inshore (Disko Bay) cod 0 1000 2000 3000 4000 0 2000 4000 6000 8000 10000 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 Pink shrimp catch (t) Cod Annual Catch (t) Cod Pink shrimp Cod (kg/mile) Shrimp (tousand tonnes) Eastern Bering Sea: Mueter Northern Iceland: Astthorsson 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0.5 1 1.5 2 2.5 3 1980 1985 1990 1995 2000 2005 2010 Cod stock size Shrimp stock size Shrimp Cod Barents Sea: Hvingel COMPARATIVE STUDIES AMONGST SUB-ARCTIC SEAS NORCAN (NORway-CANada Comparison of Marine Ecosystems) Surface Chlorophyll Concentrations from SeaWiffs Drinkwater et al., PiO, accepted This project has been comparing different ecosystem components between the Labrador Sea and the Norwegian/Barents seas. ESSAS undertakes comparative studies between different sub-arctic seas: •to gain scientific insights •to determine what processes are fundamental to sub-Arctic seas and which are unique to particular seas •to share methodologies. + warm, salty Change from out of phase to in phase CIs between the two regions in the late 1990s caused by shifts in atmospheric pressure systems (weakening of NAO). Harrison et al., PiO, accepted MENU (Comparison of Marine Ecosystems of Norway and the United States) King crab / shrimp 2 4 6 8 10 200 300 400 500 Annual mean SST (°C) Annual primary production (gC m -2 ) BS (P = 0.093) NS (n.s.) EBS (P = 0.039) GOM/GB (P < 0.001) GOA (n.s.) 0 100 200 300 400 500 600 0 10 20 30 40 Total annual PP (gC m-2) Nitrate concentration of deep source water (μM) Eastern Bering Sea (EBS) Gulf of Alaska (GOA) Alaska Russia (NOR/BAR) Greenland Norwegian Sea Barents Sea Canada USA GB GOM Gulf of Maine / Georges Bank (GOM/GB) Variations in primary production depends on deep water nitrate concentrations. Primary production increased with warming from 1998-2006 in 3 of 5 ecosystems. Drinkwater et al., PiO, 2009; Mueter et al., PiO, 2009 Analyses indicate no consistent relationship between shrimp abundances with gadoids, nor with physical variables in the different regions. Further studies are ongoing. CPUE (kg/trap) ln(recruits # millions) ln(recruits index) CPUE (kg/trap) Temperature °C Analyses of snow crab show no relationship with gadoid abundance but do show a negative relationship with temperature for all regions investigated. Temperature °C Marcello et al. Timing of the spring bloom and peak seasonal productivity are occurring progressively earlier in the year, particularly at high latitudes. ESSAS is continuing to undertake further comparative studies using both observations and models. This poster is based on the work of many ESSAS scientists whom I gratefully acknowledge and thank. Normalized Climate Indices (CIs) - cold, fresher