COMPARATIVE STUDIES AMONGST
Transcript of COMPARATIVE STUDIES AMONGST
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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 InteractionsC. Morel
West Greenland: Wieland et al. Japanese Waters: Yamamura and Sakurai
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Eastern Bering Sea: Mueter Northern Iceland: Astthorsson
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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
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Annual mean SST (°C)
An
nu
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pri
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ry p
rod
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(g
C m
-2)
BS
(P = 0.093)
NS
(n.s.)
EBS
(P = 0.039)
GOM/GB
(P < 0.001)
GOA(n.s.)
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To
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an
nu
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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