Characteristics of Nordic Marine Ecosystems Ken Drinkwater Barents - PowerPoint PPT Presentation

NCoE Research Training Course Effect Studies and Adaptation to Climate Change May 8, 2012 Characteristics of Nordic Marine Ecosystems Ken Drinkwater

Barents Sea: 1.4x10 6 km 2 , Mean depth 230 m Norwegian Sea: 1.1x10 6 km 2 Mean depth 1800 m Barents Sea Lofoten Basin Norwegian Basin

Mean Conditions: Physical Oceanography

Circulation Atlantic Inflow to the Barents Sea is on average approximately 40% that of the flow in Norwegian Sea.

Hydrographic Transect Across Norwegian Sea Salinity Temperature Extended Gimsøy Section - May/June 2003 Rey & Mork, Toktrapport, HI, 2003

Density Compensating (Passive) Fronts 0 m Strong T,S contrast T S 400 m Salinity 40 km Drinkwater et al., in prep. Weak density Norwegian Sea contrast Arctic Front σ θ June 2007 CTD data

Barents Sea Circulation Red represents Arctic/Polar Atlantic Water Waters inflow, blue the Arctic Waters and Barents green is the Sea Waters extension of the Norwegian Coastal Atlantic Waters Current and is shelf Coastal Waters water of lower salinity. The division between Atlantic and Arctic Waters is the Polar Front.

Barents Sea Temperatures Mean at 100 m

Barents Sea Opening (BSO) The Fugloya- Bjørnoya Section has had seasonal hydrographic sections taken since the 1970s while current meters have been moored for over 10 years and are continuing.

Density Compensating (Passive) Fronts Weak Surface T contrast T Storbanken Strong Surface S Front 90 km Polar Front (50-150 m) • Strong T, S, contrast • Weak density contrast S • Evidence of interleaving Våge et al., 2012 Barents Sea Polar Front σ θ August 2007 CTD data

Sea Ice Ice coverage in different months 80 ° N IX X XI 75 ° N XII VI II IV 70 ° N E 10 ° E ° 0 7 Ocean Data View 2 60 ° E 0 ° E 30 ° E 50 ° E 40 ° E

Mean Conditions: Biology

Primary Production Annual production: ~90-150 g C m -2 , Atlantic 2-3x Arctic Barents Sea ~80-180 g C m -2 Norwegian Sea

Phytoplankton Biomass Norwegian Sea June 2007 Barents Sea August 2007 West East South North Arctic Front Atlantic Atlantic Front Arctic There is no increased Jan Mayen phytoplankton Iceland biomass or Sea production at the fronts. Jan Mayen Ridge Norwegian Sea Erga et al., submitted Basedow, pers. com.

Zooplankton – Calanus finmarchicus Norwegian Sea Norwegian Shelf/Barents Sea Ocean circulation and climate Modified after M. Heath

Main Zooplankton Species Temperature C. glacialis, 2-yr at 50 m C. finmarchicus, 1-yr

Major Fish Species Hamre 1999

Capelin Herring Hamre 1999

Atlantic Cod

Polar Cod

Estimated annual biomass, production and consumption of different trophic levels. Loeng & Drinkwater 2007

Interannual Variability

Air Temperature Variability Significant warming has occurred twice in the past 100+ years in Northern Hemisphere: 1920-1950s and 1990s to present. Johannesen et al., 2004

Inter-annual variations in Atlantic water -trend since 1970s -inter-annual variations -anomalies trough the system, in general not dampened. Skagseth et al. 2008

Temperature anomalies Fugløya-Bear Island Vardø-N Observations in BSO Volume flux

Salinity Anomaly Time Series and Trends 0.15 Sea Surface Salinties Western Barents Sea Salinity Anomaly 0.05 -0.05 -0.15 1965 1975 1985 1995 2005 Salinity increases due to transport from the south providing further evidence of importance of advection.

North Atlantic Oscillation (NAO) Positive Phase of NAO Negative Phase of NAO • deeper Low over Iceland, stronger • weaker Low over Iceland, weaker High High over the Azores over the Azores • more northerly storm track • weaker storms, move southerly • Warmer, wetter in northern Europe • Colder dryer in northern Europe M. Visbeck, CLIVAR Website

Effects of the NAO Year, NAO 1958 1963 1968 1973 1978 1983 1988 1993 1998 4,00 6 4 2,00 2 0,00 NAO NAO winter index 0 Longitude -2,00 -2 -4,00 High NAO -4 -6,00 -6 6S -8,00 -8 1960 1965 1970 1975 1980 1985 1990 1995 2000 Year, longitude of 35 PSU Winter NAO index (Hurrell. 1995) and the westerly penetration of Atlantic water along 65 o 45´N. From Blindheim et al. (2000). Low NAO Blindheim et al. (2001)

Atlantic Multidecadal Oscillation (AMO) Sutton and Hodson, 2005

Barents Sea (Kola Section) Temperatures 5.5 Annual Mean Decadal 5.0 Multidecadal Temperature (°C) 4.5 4.0 3.5 3.0 2.5 1890 1940 1990 Data kindly provided by PINRO

Sep anomalies 1900-2006 Jul May Mar Jan Nov Barents Sea Sep Month Jul (Atlantic May sector) Mar Jan 1900 1920 1940 1960 1980 2000 Nov Barents Sea Sep (Arctic Jul sector) May Mar Jan 1900 1920 1940 1960 1980 2000 Heat in the Barents Sea due mostly to advection rather than air-sea heat exchange.

5.0 Kola-NAO R 2 = 0.24 1900-2001 4.5 Correlations Temperature (°C) 4.0 3.5 General positive 3.0 relationship 2.5 -5 0 5 10 15 20 25 30 35 40 NAO 0.8 The strength of 0.7 Correlation Coefficient 0.6 the relationship 0.5 has changed over 0.4 0.3 time and during 0.2 the 2000s is near 0.1 0 its maximum. 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Last year of 30-year Period

Sea Ice Cover Anomalies Barents Sea (1982-2006) 20 Sea Ice coverage anomaly, % 10 0 -10 -20 -30 -40 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Year Decadal scale variability determined by advection of heat forced by storms coming across Atlantic. Short time scale variability determined by storms crossing the Arctic that advect ice into the Barents Sea.

• Standardized anomalies based on 40 time series of meteorological, sea-ice and oceanographic conditions • Up to late 1990s out of phase relationship which are now in phase. This is related to changing atmospheric patterns. NORCAN Drinkwater et al., submitted

Effect of Warming on primary production, 1998-2006 Gulf of Maine / 500 Georges Bank (P < 0.001) Gulf of Alaska 400 (n.s.) Total annual net Bering Sea (P = 0.039) primary production (gC m -2 ) 300 200 Norwegian Sea (n.s.) Barents Sea (P = 0.093) 2 4 6 8 10 Annual mean SST (°C) Mueter et al. 2009

Krill Abundance Indices Southern Barents Sea NW Barents Sea

Norwegian Sea Zooplankton, g/m 2 2009 2000

Norwegian Sea Fish Catches Barents Sea Sea Around Us Project

Development of stocks in the Norwegian Sea 25 20 Plankton, g /m 2 Pelagic fish, million tonnes 18 20 16 14 15 12 Mackerel 10 Herring Blue whiting Plankton 10 8 6 5 4 2 0 0 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Blue Whiting Growth

Barents Sea Fish Catches Barents Sea Sea Around Us Project

Variation in fish populations

0-group fish (1980-2006) FB Aug Kola Aug FB Mar Coast Aug cod haddock herring Eastward shift in capelin distribution

0-group fish cod herring capelin haddock 1987 2004 • 1987 was a cold year • 2004 was a warm year PS 2006 (also warm) • More and further east/north

Invasive Species 2003 2004 Snake Pipefish 2005 2006

Seabirds

Future Changes?

Ice algae • With the reduction of sea ice, ice algae will decline in abundance and those animals feeding on ice algae will also decline. This will change the structure and functioning of Arctic ecosystems.

Future zooplankton production -Barents Sea 1995-2004 2045-2054 Production decreases in Arctic Waters Production increases in Atlantic Waters Ellingsen et al. (2008)

Shifts in Fish Distribution Highly likely to be a general northward movement in response to climate changes (already occurring!)

Capelin Spawning in Response to Climate Change Present Spawning Future Spawning Direction of distributional shift of adult feeding migration Huse and Ellingsen, 2008

Year 1 Year 10 Likely Polar cod retreats from subarctic into the Arctic Year 20 Year 30 Chung et al., 2008, UBC Report

Cod Recruitment and Temperature Warm Temperatures Warm Temperatures increases Recruitment decreases Recruitment 7 6 8 4 9 Recruits 10 3 Temp Mean Annual Bottom Temperature 11 2 Planque and Fredou (1999)

2 1.5 R 2 = 0.75 d(Recruitment)/dT 1 GB 0.5 0 -0.5 -1 -1.5 0 2 4 6 8 10 12 Bottom Temperature If BT < 5 ° and T warms stock recruitment generally increase If BT between 5 ° and 8.5 ° C little change in recruitment If BT >8.5 ° C recruitment generally decreases If BT 12 ° C we do not see any cod stocks

Effect on abundance of 1 ° C increase Increase No change Decrease Collapse ?

1 to 2 ° C Temperature Increase Increase No change Decrease Collapse ?