Shuyang Ma1, Jianchao Li1, Jiahua Cheng2, Yongjun Tian1* 1 Laboratory of Fishery Oceanography, Ocean University of China, Qingdao, China

2 East China Sea Fishery Research Institute, Chinese Academy of Fishery Sciences, Shanghai, China

*E-mail: yjtian@ouc.edu.cn

Session 1: Environmental control of spatio-temporal changes in population size, distribution and migration of small

pelagic fish in the ecosystem context

Variations in the catches of small pelagic fishes from China seas and its responses to

climatic regime shifts

Outline

I. SPF in the over-exploited China Seas

II. Catch variation trends and step changes in SPF

III. Climatic regime shifts in China Seas and the responses of SPF

IV. Summary

China seas as marginal seas, are largely influenced by West Boundary Current, and have significant environmental changes which will have important effects on SPF.

Components Bohai Sea, Yellow Sea, East China Sea, South China Sea Current system (except South China Sea) Warm: YSWC, TWC, KS Cold: YSCC, KCC, ZFCC

(Zheng et al, 2006)

YSCC: Yellow Sea Coastal Current YSWC: Yellow Sea Warm Current KCC: Korea Coastal Current TSWC: Tsushima Warm Current ZFCC: Zhejiang-Fujian Coastal Current TWC: Taiwan Warm Current KS: Kuroshio

China seas and currents

0

2

4

6

8

10

12

14

16

18

20

0

10

20

30

40

50

60

70

80

90

100

Chin

a ca

tch

(mill

ion

t)

Glo

bal c

atch

(mill

ion

t)

Variation trends of Global and Chinese Marine catch

Global

China

Chinese catch under over-exploitation

0

5

10

15

20

25

30

35

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

1950 1960 1970 1980 1990 2000 2010

Fish

ing

boat

s (te

n th

ousa

nd in

d)

CPU

E (t

/boa

t·yea

r)

Variation trends of CPUE and fishing boats in China

CPUE

Fishing boats

Data from Global Capture Production 1950-2014, FAO

Global: Increasing trend since 1950,

remain stable after 1990 18.2% was from China in 2014

China: Increasing rapidly since 1980 to

2000, then remained stable CPUE reduced sharply in the

1950s and kept low-level after 1980. Under the over-exploitation,

how about the SPF?

Data from Global Capture Production 1950-2014, FAO

0

200

400

600

800

1000

1200

1950 1960 1970 1980 1990 2000 2010

Catc

h/10

4 t

Catch of marine fish and SPF in China Marine fish SPF

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1950 1960 1970 1980 1990 2000 2010

SPF

cat

ch/1

04 t

SPF catch of global and China Global China

1996/97

SPF 39%

SPF 26%

SPF catch — From global to China

China marine fishes

Cods, hakes, haddocks

Tunas, bonitos billfishes

Coastal fishes

Demersal fishes

Small pelagic fishes

Others

Global marine fishes

Cods, hakes, haddocks

Tunas, bonitos billfishes

Coastal fishes

Demersal fishes

Small pelagic fishes

Others

SPF 39%

SPF 26%

FAO, 2014

Focus

Japanese sardine Sardinops melanostictus

Chub mackerel Scomber japonicas

Horse mackerel Trachurus japonicus

Japanese anchovy Engraulis japonicus

Japanese scad Decapterus maruadsi

Pacific herring Clupea pallasi

Clarify the trends of SPF in China seas Identify the responses of SPF to climate change

Catch Chinese Fishery Statistics 1950-2014 FAO Global Capture Production 1950-2014 Tsushima Stock Assessment Reports 2015

Sea Surface Temperature Grid data with resolution of 1°×1°

Climatic indices Pacific Decadal Oscillation (PDO) Southern Oscillation (SOI) Arctic Oscillation Index (AOI) North Pacific Index (NPI) Asian Monsoon Index (MOI)

Regime Shift Detection Cumulative Sum Get the variation trends and step changes of data

Principal Component Analysis Calculate the pc1 of SST in summer and winter then get the changing pattern

Correlation Analysis Explore the relationships between catch and environmental indicators

Data and analyses

Variation trends in SPF catch

0

20

40

60

80Chub mackerel

0

5

10

15

20Pacific herring

0

40

80

120

160Japanese anchovy

0

5

10

15

20

25

1950 1960 1970 1980 1990 2000 2010

Japanese sardine 0

20

40

60

80Japanese scad

0

10

20

30

1950 1960 1970 1980 1990 2000 2010

Horse mackerel

Catc

h/10

4 t Ca

tch/

104 t

Catc

h/10

4 t

-60

-50

-40

-30

-20

-10

0

10

-15

-10

-5

0

5

10

15

1950 1960 1970 1980 1990 2000 2010

Anom

alie

s/10

4 t Japanese sardine

0

10

20

30

40

50

-10

-5

0

5

10

15

20

1950 1960 1970 1980 1990 2000 2010

Cusu

m/1

04 t

Horse mackerel

Anomalies

Mean

Cusum

-100

-80

-60

-40

-20

0

-40

-30

-20

-10

0

10

20

Cusu

m/1

04 t

Japanese scad

Step changes in SPF catch

-600

-500

-400

-300

-200

-100

0

100

-30

-20

-10

0

10

20

30

40

Anom

alie

s/10

4 t Chub mackerel

1995/96 1976/77

2007/08

1983/84

-15-10-5051015202530

-5

0

5

10

15

20

Cusu

m/1

04 t

Pacific herring

1983/84

-400

-300

-200

-100

0

100

-100-80-60-40-20

020406080

Anom

alie

s/10

4 t Japanese anchovy

2000/01

1996/97

2006/07

1996/97

2007/08

2001/02

-20

-15

-10

-5

0

5

-3

-2

-1

0

1

2

3

Cusu

m

Win

ter P

DO A

nom

alie

s Winter PDO

-6

-4

-2

0

2

4

6

8

10

-4

-3

-2

-1

0

1

2

3

4

Cusu

m

Annu

al S

OI A

nom

alie

s Annual SOI

-14-12-10-8-6-4-2024

-4

-3

-2

-1

0

1

2

3

4

Cusu

m

Win

ter A

O A

nom

alie

s Winter AO

-5

0

5

10

15

20

25

30

35

-8

-6

-4

-2

0

2

4

6

8

Cusu

m

Win

ter N

PI A

nom

alie

s Winter NPI

-10

-5

0

5

10

15

20

25

30

-10-8-6-4-202468

1950 1960 1970 1980 1990 2000 2010

Cusu

m

Win

ter M

OI A

nom

alie

s Winter MOI 1977: PDO

1989: PDO

2015: PDO

1989: AO

1977: NPI 2016: NPI

1987: MOI

2005: MOI

-0.6-0.4-0.2

00.20.40.60.8

11.21.4

1950 1960 1970 1980 1990 2000 2010

RSI

Regime Shift Index (RSI)

1976/77 1988/89 1976/77 1988/89

Variation pattern in Climatic indices

-5

-4

-3

-2

-1

0

1

2

3

Yellow Sea

-8

-6

-4

-2

0

2

PC1

Scor

es

Bohai Sea -4

-3

-2

-1

0

1

2

3

Bohai Sea

-5

-4

-3

-2

-1

0

1

2PC

1 Sc

ores

Yellow Sea

-3

-2

-1

0

1

2

3

1950 1960 1970 1980 1990 2000 2010

PC1

Scor

es

East China Sea -2.5

-2-1.5

-1-0.5

00.5

11.5

22.5

1950 1960 1970 1980 1990 2000 2010

East China Sea

1995/96 1986/87

Summer

China

Variation pattern in SST In China Seas Winter

1977: PDO

1989: PDO

2015: PDO

1989: AO

1977: NPI 2016: NPI

1987: MOI

2005: MOI

-1

-0.5

0

0.5

1

1.5

RSI

Climatic indices

[类别名称]: 1

1996: 1

[类别名称]: 1

[类别名称]: 2

[类别名称]: 2

[类别名称]: 3

[类别名称]: 3, 4

2002: 5

[类别名称]: 6 -1.5

-1-0.5

00.5

11.5

2

RSI

Catch, China

1: Chub mackerel 2: Pacific herring 3: Japanese anchovy 4: Japanese sardine 5: Japanese scad 6: Horse mackerel

2007: 1

1988: 4

1983: 5 1994: 3, 5

1961: 6 1978: 6

1987: 6 1997: 1, 6

2011: 6

-1

-0.5

0

0.5

1

1950 1960 1970 1980 1990 2000 2010

RSI

SST pc1s

Numbers 1-6 represent SST pc1 of different seas.

Catch step changes 1976/77 1996/97 2007/08

Climatic regime shifts 1976/77 1988/89 1995/96 (step change in SST)

Response of SPF to climate change

Chinese SPF catch responded well to the climatic regime shifts in 1976/77 and 1995/96, but no response to the shift in 1988/89.

Variation in SPF catches are driven by climatic regime shifts, particularly the thermal regime shifts.

Table 1 Correlation analysis between climatic indices, SST pc1s and SPF catch anomalies in China.

Asterisks denote significance at the following alpha levels: * 0.05>p>0.01, ** 0.01>p

Climate indices and SST pc1s Chub mackerel

Pacific herring

Japanese anchovy

Japanese sardine

Japanese scad

Horse mackerel

PDO 0.45** -0.3* 0.42* SOI AO -0.45* NPI -0.3* -0.43* MOI

Bohai Summer PC1 0.56* Bohai Winter PC1

Yellow Sea Summer PC1 0.44* Yellow Sea Winter PC1 0.3*

East China Sea Summer PC1 0.57** 0.64** 0.48** 0.5* East China Sea Winter PC1 0.62** 0.61** 0.47**

Impact of environmental indices on SPF

0

10

20

30

40

50

60

70

1980 1985 1990 1995 2000

Catc

h/10

4t

Japanese scad

Cold Winter

Cold Summer

Warm Winter

Cold Summer

Warm Winter

Warm Summer

1986/87

1995/96

Responses of SPF to SST variation pattern

Rising trend with time lag between winter and summer.

Catch trends responded well to the SST variation pattern.

0

20

40

60

80

100

120

140

160

Catc

h/10

4t

Japanese anchovy 0

10

20

30

40

50

60

Catc

h/10

4t

Chub mackerel

Increasing Decreasing Collapse

Responses of Tsushima catch to the changing SST

China

Japan

Summary

I. SPF catch in China showed decadal variations with step changes around 1976/77, 1996/97 and 2007/08.

II. SPF catch in China responded well to the climatic regime shifts, particularly the thermal regime shifts, occurred in 1976/77 and 1995/96, but no significant response to the shift in 1988/89.

III. SST variation pattern with regime shift occurred in winter in 1986/87 and in summer in 1995/96 had important effects on SPF catch.

Future works

Cold Winter

Cold Summer

Warm Winter

Cold Summer

Warm Winter

Warm Summer

1986/87

1995/96

Based on data collection such as life history traits by species, to verify the effects of the SST variation pattern on SPF.