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Gulf of Alaska. Climate and Oceanography. Pacific Decadal Oscillation. positive phase negative phase. tao.atmos.washington.edu/pdo/. Winter PDO score (November – March). jisao.washington.edu/pdo/PDO.latest. Pacific Decadal Oscillation. Oceanographic correlates:

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Gulf of Alaska

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Gulf of alaska

Gulf of Alaska

Climate and Oceanography


Pacific decadal oscillation

Pacific Decadal Oscillation

positive phase negative phase

tao.atmos.washington.edu/pdo/

Winter PDO score

(November – March)

jisao.washington.edu/pdo/PDO.latest


Pacific decadal oscillation1

Pacific Decadal Oscillation

  • Oceanographic correlates:

  • Atmospheric pressure- Air / sea temperature

  • Freshwater input- Surface salinity

  • - Mixed layer depth- Upwelling / downwelling strength

  • Wind stress- Sea ice extent / time of thaw

  • Nutrient flux- Current strength / gyre circulation

  • Solar radiation absorption- Aerosol (dimethylsulfide) production

  • Primary productivity- Secondary productivity


Pacific decadal oscillation2

Pacific Decadal Oscillation

Effect on trophic level of Alaska’s commercial fishery landings 1964-2003


Pacific decadal oscillation3

Mantua et al. 1997,

Minobe 1997

Pacific Decadal Oscillation

PDO journal articles listed in Web of Science


Gulf of alaska

Principal component 2 - Victoria Pattern

2.0

1.0

0.0

Victoria Pattern score

-1.0

-2.0

(Bond et al. 2003. Geophys. Res. Let. 30:2183)

-3.0

1950

1960

1970

1980

1990

2000

jisao.washington.edu/pdo/PDO.latest


Gulf of alaska

P > 0.1

P < 0.0001

Community state

(NMDS axis1)

(Rodionov. 2004. Geophys. Res. Let. 31:L09204)

P < 0.0001

Catch composition of small-mesh trawls in three Alaska Peninsula Bays

July – October hauls; Chignik-Castle, Kuiukta, Pavlof Bays

More groundfish

More

capelin & shrimp


Gulf of alaska

Average North Pacific temperature

Average global temperature

Temperature anomaly

relative to 1961-1990 (ºC)

Temperature anomaly

relative to 1961-1990 (ºC)

East Anglia University, UK

www.cru.uea.ac.uk/cru/data/temperature/#datdow

East Anglia University, UK

www.cru.uea.ac.uk/cru/data/temperature/#datdow

Winter PDO score

(November – March)

jisao.washington.edu/pdo/PDO.latest


Gulf of alaska

Overview: GOA Climate and Oceanography Posters

GEM Biophysical Observations Aboard the Alaskan State Ferries, E. Cokelet et al.

Early Holocene / Late Pleistocene Shoreline North of the Present Ice Margin of the Bering Sea, A. Pasch & N. Foster

A Catalog of Marine Gap Winds for the Western and Northern Gulf of Alaska, J. Curtis & N. Bond

Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska, M. Janout et al.

Nutrient Dynamics in the Gulf of Alaska, C. Mordy et al.

Oceanographic Boundary Conditions to Cook Inlet, W. Pegau et al.

hour

day

month

year

decade

century

millennium

Time scale of data collection


Gulf of alaska

A Catalog of Marine Gap Winds for the Western and Northern Gulf of Alaska

Joel Curtis and Nicholas Bond


Gulf of alaska

Oceanographic Boundary Conditions to Cook Inlet

W. Scott Pegau, Edward Cokelet and Susan Saupe


Gulf of alaska

Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska

Markus Janout, S. Okkonen, T. Weingartner, D. Musgrave, and T. Royer

surface salinity

sea surface height

bathymetry


Gulf of alaska

Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska

Markus Janout, S. Okkonen, T. Weingartner, D. Musgrave, and T. Royer


Gulf of alaska

Yakutat Eddies and Shelf/Slope Exchange in the Coastal Gulf of Alaska

Markus Janout, S. Okkonen, T. Weingartner, D. Musgrave, and T. Royer


Gulf of alaska

GEM Biophysical Observations Aboard the Alaskan State Ferry Tustumena

Edward Cokelet, A. J. Jenkins, W. S. Pegau, C. W. Mordy, and M. Sullivan


Gulf of alaska

GEM Biophysical Observations Aboard the Alaskan State Ferry Tustumena

Edward Cokelet, A. J. Jenkins, W. S. Pegau, C. W. Mordy, and M. Sullivan


Gulf of alaska

Nutrient Dynamics in the Gulf of Alaska

Calvin Mordy, Peter Proctor, Sigrid Salo, Phyllis J. Stabeno, and David P. Wisegarver


Gulf of alaska

Invertebrate Evidence for an Early Holocene / Late Pleistocene Shoreline North of the Present Ice Margin of the Bering Glacier

Anne D. Pasch and Nora R. Foster


Gulf of alaska

Mike Litzow1 & Lorenzo Ciannelli2

1Alaska Fisheries Science Center, NOAA Fisheries

2Center for Ecological and Evolutionary Synthesis, University of Oslo

Has Climate Change Produced Oscillating Ecosystem Control in the Gulf of Alaska?


Taxa involved in pdo driven community reorganizations

Taxa involved in PDO-driven community reorganizations

SalmonShrimp

Zooplankton Gadids

Flatfishes

CapelinJellyfish

Seabird / pinniped diets

Sardines

Anchovies

Zooplankton

SalmonAnchovies

Zooplankton Sardines

MackerelHake

RockfishSablefish

Seabirds

Sardines

Anchoveta

Seabirds

Tuna

Tuna


Gulf of alaska

Estimated age 3+ biomass

76/77

regime shift

103 metric tons

Average of models 2 & 3,

2006 SAFE document

Proportion of occurrence in NMFS bottom trawls

Warm regime

1978 - 2005

Cold regime

1954 - 1975

Proportion of hauls with cod

Proportion of hauls with cod

PDO regime shift and Gulf of Alaska cod abundance


Gulf of alaska

Pavlof Bay small-mesh trawl data

CPUE (kg / km towed)

July – October, n = 593 hauls


Gulf of alaska

Cod-shrimp interactions

Cod exercise top-down control on shrimp populations in N. Atlantic

(Worm and Myers 2003. Ecology 84:162-173)

Cod regulation cascades to zooplankton, phytoplankton and nutrients

(Frank et al. 2005. Science 308:1621-1623)


Gulf of alaska

Climate effects on cod-shrimp interactions

N. Pacific biological time series show non-linear dynamics / alternate stable states

(Hsieh et al. 2005. Nature 435:336-340)

Alternate stable states predict different ecological controls under different climate regimes – i.e., oscillating control

(Scheffer et al. 2001. Nature 413:591-596)


Gulf of alaska

Oscillating control hypothesis:

1970s climate regime shift resulted in change between bottom-up and top-down control in Gulf of Alaska cod-shrimp system

Approach:

2) Non-additive modeling approach to test for different control under different climate regimes

(Cianelli et al. 2004. Ecology 85:3418-3427,

Cianelli et al. 2005. Proc. R. Soc B 272:1735-1743)

Approach:

1) Cod-shrimp abundance correlations

negative correlation = top down control

positive or weak correlation = bottom-up control

(Worm and Myers 2003. Ecology 84:162-173)

multi-modal distribution of controlling parameters

necessary condition of alternate states

(Scheffer et al. 2001. Nature 413:591-596)


Gulf of alaska

1) Correlation approach

1

Bottom-up control

94

82

89

95

74

86

87

85

96

88

97

02

84

81

83

00

03

98

75

01

Correlation strength

(running 5-yr Pearson’s r)

0

99

80

90

92

91

93

Top-down control

79

76

77

78

-1

0

1

-2

-1

Count

Temperature index (PC1 score)

Climate regulation of top-down and bottom-up ecosystem control

Temperature effects on running 5-yr correlation between cod and standardized prey abundance (capelin and 4 shrimp species)

Model R2 = 0.42, P(temperature) = 0.005


Non additive modeling approach

Non-additive modeling approach

Selects between competing models:

Generalized Additive Model (GAM): response variable estimated by adding effects of smoothing functions for each explanatory variable

Nonadditive model: constructs separate GAMs for data below and above threshold value in some environmental or biological parameter

Choice of additive or non-additive model, and selection of threshold value, made by minimizing # of parameters and maximizing model fit to data


Gulf of alaska

2) Non-additive modeling approach

Effect on cod abundance

P < 0.001

P = 0.03

P = 0.01

Log (cod CPUE) lag 1 yr

Temperature index (PC1 score)

Prey abundance index

Additive model of cod abundance

Model R2 = 0.74


Gulf of alaska

2) Non-additive modeling approach

More groundfish

Threshold

Community state

(NMDS axis 1)

More shrimp & capelin

Below threshold

Above threshold

P = 0.003

P = 0.08

Effect on pink shrimp abundance

Effect on pink shrimp abundance

Log (cod CPUE)

Temperature (PC1 score)

Non-additive factors affecting pink shrimp abundance

Model R2 = 0.85


Conclusions

Conclusions

1) Support for hypothesis that climate change has produced oscillating control in Gulf of Alaska – shifts between bottom-up and top-down control

- temperature regulation of top-down and bottom-up control of cod-shrimp interactions

- non-additive control of shrimp populations,

depending on community state

2) Results demonstrate limitations in using annual-scale variability to study decadal-scale patterns in climate-ecosystem interactions


Acknowledgements

Acknowledgements

Paul Anderson, Dave Jackson, Alisa Abookire, Franz Mueter

and everyone who helped collect small-mesh trawl data through the years…


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