1970 1980 1990 2000

0.0

0.4

0.8

Scale

d a

bundance

COMPARATIVE STUDIES AMONGST SUB-ARCTIC SEAS

Ken Drinkwater (ken.drinkwater@imr.no)

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 InteractionsC. Morel

West Greenland: Wieland et al. Japanese Waters: Yamamura and Sakurai

1970 1975 1980 1985 1990 1995 2000 2005 2010

Ca

tch

('0

00

t)

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

19

81

19

83

19

85

19

87

19

89

19

91

19

93

19

95

19

97

19

99

20

01

20

03

20

05

20

07

Pin

k s

hri

mp

ca

tch

(t)

Co

d A

nn

ua

l C

atc

h (

t)

Cod

Pink shrimp

Co

d (

kg

/m

ile

)

Sh

rim

p (

tou

sa

nd

to

nn

es)

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

sto

ck

siz

e

Sh

rim

p s

tock

siz

e

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)

An

nu

al

pri

ma

ry p

rod

ucti

on

(g

C 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

To

tal

an

nu

al

PP

(g

Cm

-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

USAGB

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.

CP

UE

(kg/tra

p)

ln(r

ecru

its #

mill

ions)

ln(r

ecru

its index)

CP

UE

(kg/tra

p)

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