Decadal scale variation of Decadal scale variation of copepod community structure in the Oyashio copepod community structure in the Oyashio

based on the Odate Collectionbased on the Odate Collection

PIC

ES 1

3PI

CES

13t

hthA

nnua

l Mee

ting

Ann

ual M

eetin

g

Sanae CHIBASanae CHIBA11, H. Sugisaki, H. Sugisaki22, T. Saino, T. Saino1,31,3

1Frontier Research Center for Global Change (FRCGC/JAMSTEC)2Tohoku National Fisheries Research Institute

3Nagoya University

chibas@jamstec.go.jpchibas@jamstec.go.jp

Regime shiftIn

trod

uctio

nIn

trod

uctio

nOscillation

correlations

Climate EcosystemHow link?

mechanisms

Advantage of Detailed Zooplankton Analysis Advantage of Detailed Zooplankton Analysis for Climatefor Climate--Ecosystem Change StudiesEcosystem Change Studies

Intr

oduc

tion

Intr

oduc

tion

There are some historical zooplankton collections waiting to be analyzed

Their community structure and biological states preserve a state of past events

Their body may tell us...“how was the ambient environmental condition”

“where are they from”

Zooplankton samples taken in water adjacent to Japan 1950s - present

Odate collection station map(total # > 20,000)

Oyashio

Kuroshio

Transition area

Wet weight data were analyzed by Odate (1994) and archived by Tohoku Fisheries Research Institute.

Oda

te C

olle

ctio

nO

date

Col

lect

ion

Process study on longProcess study on long--term variation of term variation of lower trophic level ecosystemlower trophic level ecosystemin the western North Pacificin the western North Pacific

The ODATE projectThe ODATE project20032003--2005 (6?) 2005 (6?) FYFY

Funded by the Japanese Ministry of EnvironmentFunded by the Japanese Ministry of Environment

11H. Sugisaki, H. Sugisaki, 11H. Saito, I. H. Saito, I. 22Yasuda, Yasuda, 33M. Noto,M. Noto,44S. Chiba, S. Chiba, 44T. Tadokoro, T. Tadokoro, 55T. KobariT. Kobari

11Tohoku Fisheries Research InstituteTohoku Fisheries Research Institute22Tokyo UniversityTokyo University33National Fisheries Research Institute National Fisheries Research Institute 44Frontier Research Center for Global Change/JAMSTECFrontier Research Center for Global Change/JAMSTEC55Kagoshima UniversityKagoshima University

To elucidate mechanisms of basin scale, multiTo elucidate mechanisms of basin scale, multi--decadal decadal change in marine ecosystemschange in marine ecosystems

Subject 1establish

Zooplankton database

*insemination of results

Microscopic analysis

Subject 4Variability of

plankton community structure

*modeling ocean circulation *construct climate-ocean data set

feedback

feedback

zooplankton composition data

Subject 3Physical environments

&primary productivity

Subject 2Climate - Ocean interaction

Com

pone

nts

of th

e O

date

Pro

ject

Com

pone

nts

of th

e O

date

Pro

ject

1. 1. Copepods community analysis Copepods community analysis 2. 2. Quantitative and phenological changes of Target speciesQuantitative and phenological changes of Target species3. 3. δδ1515N analysis of target species for basin scale comparisonN analysis of target species for basin scale comparison

(Takahashi et al. 2002, DSR II, 49)(∆pCO2)bio = (pCO2 at T mean) max - (pCO2 at T mean) min

2003

2003

-- 200

420

04FY

Tar

get:

Oya

shio

Dom

ain

FY T

arge

t: O

yash

io D

omai

n

Extensive spring bloomEfficient BCP function

Criteria for OyashioT< 5C at 100m depth

Sele

ctio

n of

Dat

aSe

lect

ion

of D

ata

Temporal dis tibution of Data

0

50

100

150

200

250

1970 1975 1980 1985 1990 1995 2000year

Julia

n D

ay

Mar.Apr.MayJun.Jul.Aug.

Monthly mean abundance for each year for each species

Number of copepod species observed: 120

Number of samples analyzed: 578 (of >1300)

Year/Season1972-2001March – August (of Feb-Dec from 1960s)

Target area37-43N, 142-147EBottom depth > 500 m

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Total copepod abundance (log(inds/1000m3+1)) Normalized monthly anomalymonth

productive season: short

Time series of total copepods abundance [log (inds.m-3 + 1)]

March-August, 1972-2001

Spring production: small

productive season: elongated

1988/89 regime sift

1976/77 regime sift

1998 regime sift?R

egim

e Sh

ift &

Oya

shio

Cop

epod

sR

egim

e Sh

ift &

Oya

shio

Cop

epod

s

960 61 62 63 64 65 66 967 68 69 70 971 72 73 74 75 76 77 978 79 80 81 982 83 84 85 86 87 88 89 90 91 92 993 94 95 96 997 98 99 00 01 02

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

-

-

-

-

-

0

0

1

1

2

2PDO

PDO

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Neocalanus fremingeri3 4 5 6 7 8

Pesuedocalanus minutus3 4 5 6 7 8

Scolecithricella minor3 4 5 6 7 8Neocalanus cristatus

3 4 5 6 7 8

Pseudocalanus newmani3 4 5 6 7 8

Metridia okhotensis3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Neocalanus plumchrus

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Eucalanus bungii

3 4 5 6 7 8

Oithona similis3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Oithona atlantica

3 4 5 6 7 8Metridia pacifica

3 4 5 6 7 8

Mesocalanus tenuicornis

Time series of abundance of dominant copepod species [inds. 1000 m-3)]

species

Acartia omorii Calanus pacificus s.l.Clausocalanus parapergens Corycaeus affinis Ctenocalanus vanus Eucalanus bungii Mesocalanus tenuicornis Metridia okhotensis Metridia pacifica Neocalanus cristatus Neocalanus flemingeri Neocalanus plumchrus Oithona atlantica Oithona similis Paracalanus parvus Pseudocalanus minutus Pseudocalanus newmani Scolecithricella minor

Abundance correction for DVM influence was made

Dominant species list Community classificationC

omm

unity

Ana

lysi

s: M

etho

dsC

omm

unity

Ana

lysi

s: M

etho

ds > 1% abundance at any month

Cluster Dendrogram

Com

mun

ity A

naly

sis:

Res

ults

Com

mun

ity A

naly

sis:

Res

ults

Subarctic speciesTemperate specieswidely distributed speciesby Chihara & Murano (1994)

-1

-0.5

0

0.5

1

1.5

-1 0 1 2

Ao

C p

ClP aCa

Cv

Eb

Mt Mo

Mp NcNf

Np

Oa

Os

Pp

P mP n

Sm

Gr o u p 1Gr o u p 3

Gr o u p 2

month of the peak abundance

AprilMayJuneJuly

R-m o d e 2 : y r -a n o m a ly (p e a k m o n t h a n a ly s is )

Group AGroup CGroup B

NMDS ordination plot of copepods cluster groups. C

omm

unity

Ana

lysi

s: R

esul

tsC

omm

unity

Ana

lysi

s: R

esul

ts SpringSummer

Group spp. code species

Group APm Pseudocalanus minutus Nc Neocalanus cristatus Nf Neocalanus flemingeri Os Oithona similis

Group BEb Eucalanus bungii Mo Metridia okhotensis Mp Metridia pacifica Pn Pseudocalanus newmani Np Neocalanus plumchrus

Group CCp Calanus pacificus s.l.Mt Mesocalanus tenuicornis Oa Oithona atlantica Pp Paracalanus parvus ClPa Clausocalanus parapergens Ca Corycaeus affinis Cv Ctenocalanus vanus Ao Acartia omorii

OutlierSm Scolecithricella minor

Species list for each cluster group

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Group 3Group 1 Group 2

2.5

2.0

1.5

1.0

0.5

0.0

0.5

1.0

1.5

2.0

2.5

Spring Community

Time series of normalized anomaly of average copepods abundance [log(inds m-3)] for each cluster group (average = 0, SD = 1)　

Com

mun

ity A

naly

sis:

Res

ults

Com

mun

ity A

naly

sis:

Res

ults Early Summer

CommunitySummer

Community

Timing of peak abundance

Com

mun

ity A

naly

sis:

Res

ults

Com

mun

ity A

naly

sis:

Res

ults

Spring Community

Early Summer Community

Summer Community

1971-1976

Mean monthly abundance of community groups

1977-1988

Productive seasonstart LATE, end EARLY

-3

-2

-1

0

1

2

3

Mar Apr May June July Aug

-3

-2

-1

0

1

2

3

Mar Apr May June July Aug

-3

-2

-1

0

1

2

3

Mar Apr May June July Aug

P<0.1, Man-Whitney U

Cold winter& light limited systemDeep wintertime mixing delayed spring bloom?

Com

mun

ity A

naly

sis:

Res

ults

Com

mun

ity A

naly

sis:

Res

ults

Spring Community

Early Summer Community

Summer Community

1971-1976

Mean monthly abundance of community groups

1977-19881989-1999

Sporadic abundance increase in summer

-3

-2

-1

0

1

2

3

Mar Apr May June July Aug

-3

-2

-1

1

2

3

Mar Apr May June July Aug

-3

-2

-1

0

1

2

3

Mar Apr May June July AugP<0.1, Man-Whitney U

Spring abundance:small

Sum

mar

ySu

mm

ary

Copepods community in the Oyashio varied in decadal scale, both in abundance and phonology. Regime shifts related?

But..community structure differed between the early 1970s and 1990s.- Variation was “one-way” (not oscillation)

Decadal scale variation pattern differed among the 3 seasonal communities.

- Changes in the late 1970s were obvious only in the Spring Community and Early Summer Community: delayed and short productive season.

- Changes in the late 1980s - early 1990s) were obvious only in the Early Summer Community and Summer Community: low spring production, sporadic abundance increase in summer

Environmental variation from Winter to Spring was responsible for the changes in the late 1970s

Spring to Summer the late 1980s

Different mechanisms work for decadal scale variation of the lower trophic levels in Winter

and Summer

To be To be continuedcontinued

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5PDO

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5AO (Winter)

~1976 1976/77~1988/89 1988/89~1998?

Winter

Summer

ＰＤＯ

AＯ

Decadal scale variation: winter vs. summer　

AL weak AL strong AL strong

ＯＨ strong ＯＨ strongＯＨ weak

Wind strong

WindstrongWind weak

７.　補足資料 仮説

冬の十年スケール変動と夏の十年スケール変動をもたらす気候変化とそれに伴うメカニズムは異なるものである

(Batcheder & Powell, 2000, Prog. Oceanog. 53: 105-114)

Ctenocalanus vanes

3 4 5 6 7 83 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Clausocalanus parapergens

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Paracalanus parvis

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Acartia omorii

Corychaeus afiinis

3 4 5 6 7 8

Calanus pacificus

3 4 5 6 7 8

Time series of abundance of dominant copepod species [inds. 1000 m-3)]

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

3 4 5 6 7 8

1975

1980

1985

1990

1995

2000

Group 1 Group 2 Group 3

R-mode cluster group map (2) interannual variation of the month of peak abundance

Group A Group CGroup B

4月5月に個体群密度のピークが来る

仲間＝春群集5月6月に個体群密度のピークが来る

仲間＝初夏群集6～8月に個体群密度のピークが来る

仲間＝夏群集

Variation in timing of peak abundance for each cluster group

Fig. 10　各カイアシ類群集の月毎に正規化したLog平均密度, 年ごとに3-8月の平均＝０標準偏差が１とした）の時系列（オレンジが正偏差、緑が負偏差）

注）30年間の生物量のピーク時期のずれのみを示している。

high

low

密度のピーク