Fluxes of Atlantic and Polar waters and their

impact on fish, examples from Iceland

Steingrímur Jónsson1,2

Héðinn Valdimarsson1

1Marine Research Institute and 2University of Akureyri

NIIC

NIIC

NIJ

EIC

Two primary water masses:

Atlantic Water: T>5°C; S>35

Polar Water: T<0°C; S<34,4

August-September

August-September

NISE database

T – 50m

Spring 1995

S = 35.0

S = 35.0

4°C

4°C

S – 50m

Spring 1995

S – 50m

Spring 2003

T – 50m

Spring 2003

Sea ice on

March 15th 2005

The outflow from the

Arctic Ocean

passes close to Iceland

NIIC

NIIC

NIJ

EIC

Timeline for the measurementsADCP

The E-W component of the current 2013-2014

-10 -5 0 5 10 15 20 25 30 35 40 45

nautical miles

500

400

300

200

100

0

De

pth

(m

)

E-W component of the current measured with a vessel mounted ADCPat Hornbanki section in november averaged for the years 2001-2004 in cm/s

H1

H3H2

CTD station

MooringH

orn

ban

ki

H4

50 m depth

80 m depth

150 m depth

Monthly mean transport of AW and the associated heat transport

Annual average of temperature over the depth interval between

50 and 150 m at the stations, SI2-4 shown as red thick line.

Lagged correlation between the daily AW transport and the north-south

component of the wind at 67.5°N and 22.5°W for the period 1999-2010.

Maximum

correlation at 1

day lag

AW transport and N-S wind for the period

September 1999 – August 2000

Higher

temperature

and salinity

After 1995Before 1995

Hátún et al. 2005

Why is the NIIC important?

• It carries with it nutrients and creates

conditions favorable for phytoplankton

growth

• It is the drift route for the larvae of many

of the most commercially important fish

stocks in Icelandic waters

• It is a source of heat to the area that

affects climate on land as well as in the

sea

Temperature and Salinity at bottom for all months

NISE dataset (2007)

L. Zhai et al. (2012)

Primary production through water column for the period March - October

Begg and Marteinsdóttir 2000

Mean (1970-1998) spatial distribution of relative abundance

(number/nm) of pelagic juvenile cod

T – 50m

Spring 1995

S = 35.0

S = 35.0

4°C

4°C

S – 50m

Spring 1995

S – 50m

Spring 2003

T – 50m

Spring 2003

Haddock 1995Distribution of 0-

group haddock

in August 1995

and 2003

MRI (1995)

MRI (2004)

Landings in numbers by age (millions) in the years 1979–2012.

Year 2 3 4 5 6 7 89+

2005 2.405 9.45 6.929 25.421 13.778 4.584 0.809 0.488

2006 0.241 10.038 21.246 6.646 18.84 7.6 2.18 0.525

2007 0.782 3.884 42.224 22.239 3.354 9.952 2.74 0.7

2008 2.316 4.508 9.706 53.022 11.014 1.717 3.033 1.007

2009 1.066 3.185 4.886 8.892 35.011 5.733 0.726 1.89

2010 0.121 6.032 7.061 4.806 6.766 17.503 1.874 0.882

2011 0.253 1.584 11.797 5.08 2.853 3.983 6.22 0.677

2012 0.196 1.322 3.421 13.107 2.223 1.231 2.48 3.032

Weight at age from commercial catches (g) in the years 1979–2013.

Year 2 3 4 5 6 7 8 9

2005 339 886 1265 1506 1916 2323 3028 3055

2006 402 749 1093 1495 1758 2163 2555 3260

2007 510 748 988 1346 1840 2062 2350 2685

2008 383 636 857 1125 1575 2149 2417 2764

2009 452 841 960 1131 1352 1757 2364 2652

2010 447 756 1092 1294 1448 1685 2188 2534

2011 588 905 1122 1455 1688 1914 2094 2599

2012 668 978 1222 1492 1903 2164 2366 2704

Value of increased haddock stock

• Average catch from 1971-2000 was 50,769 tons

• The catch from the 2003 year class was 149,906

tons

• There was a surplus catch of 99,137 tons

• The export value of the surplus catch was 269

million USD

ICES (2012)

Temperature anomaly

Salinity anomaly

Greater variability in the north than in the south west

Weight of 3 year old capelin and salinity deviation at Siglunes north of Iceland

Weight of 6 year old cod and the capelin biomass

ATLANTIC WATER DOMINATING POLAR WATER DOMINATING

INCREASED PRIMARY PRODUCTION REDUCED PRIMARY PRODUCTION

HIGH STOCK OF ZOOPLANKTON LOW STOCK OF ZOOPLANKTON

HIGH CAPELIN BIOMASS LOW CAPELIN BIOMASS

INCREASED COD GROWTH AND YIELD REDUCED COD GROWTH AND YIELD

Astthorsson and Vilhjálmsson (2002)

Conceptual model of the ecosystem in Icelandic waters

The path of the “Great Salinity Anomaly” in the North Atlantic

Dickson et al. (1988)

1968

1969-70

1971-72

1976

The size of the anomaly was about 10.000 km3 of extra freshwater over 5 years, Curry and Mauritzen (2005)

Freshwater thickness in the Beaufort Sea

Krishfield, R. A. et al. (2013)

Giles, K. A. et al. (2012)

Freshwater in the Beaufort Sea has increased by

10.000 km3 during the last decade

•The research leading to these results has received

funding from the European Union 7th Framework

Programme (FP7 2007-2013), under grant agreement

n.308299

•NACLIM www.naclim.eu