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Current Fish Stock Management Procedure of Walleye Pollock in

Japanスケトウダラの資源管理

Takashi Matsuishi, Ph. D.Associate Prof. Hokkaido Univ.

北海道大学大学院水産科学研究院准教授松石 隆

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Takashi MATSUISHI (1964- )

MSc (Tokyo Univ.), PhD (Tokyo Univ.)

Major

Biometry (stock assessment / fisheries management)

Cetology (stranding / harbour porpoise)

Associate Prof.

Lab. Bioresource Science, Fac. Fisheries Sciences

Hokkaido Univ.

Reviewer of Stock Assessment

Fisheries Research Agency (Tohoku, Sea of Japan)

Hokkaido Local Government

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United Nations Convention on the Law of the Sea 国際海洋法条約

Since the ratification of the United Nations Convention on the Law of the Sea in 1996

The scientific assessments of fishery stocks have been increasingly important.

The Convention mandated the management of living resources in EEZ

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Management in the Convention

For the living resources in EEZ

Coastal nation should

determine allowable catch

maintain

through proper conservation and management measure

taking into account the best scientific evidence available

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Procedure of Coastal Stock Management in Japan

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Outline

Data collection by Prefectural Fishery Experimental Centres and Fisheries Research Agency (FRA)

Stock assessment by FRA and determine the Allowable Biological Catch (ABC)

Determine the Total Allowable Catch (TAC) by Fishery Agency(FA) of Japan, and distribute the quota to various fisheries

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Data CollectionTarget stocks

44 species 76 stocks (2010)

Only for coastal stocks (excluding international stocks such as salmon, tunas etc)

Fisheries Research Centrefisheries research centres in 46 prefectures

They collect catch statistics, lengthcomposition, age composition, sex ratio, maturity, etc.

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Stock assessment / FRAStock assessment sheet mentions as follows;

Basic biology and ecology of the stock

Current stock and fisheries status

Population EstimationVirtual Population Analysis

Acoustic Survey Analysis etc.

Prediction of the future population dynamics

Allowable Biological Catch ABC in the next year

Researchers in Universities join as reviewers for determining the ABC

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Total Allowable Catch / FATarget stocks: 8 species 19 stocks

Determined based on ABC taking into account the socio-economic considerations

TAC sometimes exceeds ABC

Yearly total catch of the species should be under TAC, and fishery will be stopped by orders of government when the total catch reaches to TAC.

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Species under TAC regulation

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TAC Regulated FishEnglish Name Scientific Name

Pacific saury Cololabis saira

Walleye Pollock Theragra chalcogramma

Horse mackerel Trachurus japonicus

Sardine Sardinops melanostictus

Mackerel / Southern mackerel

Scomber japonicus /

Scomber australasicus

Japanese common flying squid

Todarodes pacificus

Snow crab Chionoecetes opilio

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TAC and Catch in 2009

Species TAC Catch C/TAC

Saury 455,000 316,000 69%

Pollock 227,000 219,000 97%

Horse mackerel 208,000 150,000 72%

Sardine 61,000 49,000 80%

Mackerels 575,000 442,000 77%

Flying squid 333,000 191,000 57%

Snow crab 6,423 4,477 70%

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ABC and TAC in 2009

Species ABC TAC TAC/ABC

Saury 621,000 455,000 73%

Pollock 155,000 227,000 146%

Horse mackerel 200,000 208,000 104%

Sardine 52,000 61,000 117%

Mackerels 466,000 575,000 123%

Flying squid 421,000 333,000 79%

Snow crab 7,054 6,423 91%

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ABC and Catch in 2009

Species ABC Catch C/ABC

Saury 621,000 316,000 51%

Pollock 155,000 219,000 141%

Horse mackerel 200,000 150,000 75%

Sardine 52,000 49,000 94%

Mackerels 466,000 442,000 95%

Flying squid 421,000 191,000 45%

Snow crab 7,054 4,477 63%

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Walleye Pollock

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Walleye Pollock

“The largest remaining source of palatable fish in the world” (Clover

2004)

One of the most important fisheries resources in Japan

Mainly for Roe (egg) products and Fish Cake (Surimi)

Korean eat it as hot-pot food (Chige)

http://www.marusui.co.jp/shop/38_9.html

http://www.gyoren.or.jp/melma/041120mag_g.html

http://wpedia.search.goo.ne.jp/

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Stocks around Japan

Sea of

JapanCatch (2009)

15,000t

Nemuro

Catch (2009)

9,500t

Pacific

Catch (2009)

169,000t

Okhotsuku

Catch (2009)

26,000t

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TAC by Stocks

Stock TAC TAC/ABC C/TAC C/ABC

J 15,000 146% 100% 146%

N 13,000 140% 73% 102%

O 27,000 201% 96% 194%

P 169,000 139% 100% 139%

Total 227,000 146% 97% 142%

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Catch of Walleye Pollock (JS)C

atch

100

0ｔ

Korea

Main land

Hokkaido Gillnet

Hokkaido Trawl

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Reproduction RateR

ecru

it pe

r S

SB

(/kg

)

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Estimated Population Exploitation Ratio

E-ratio Popul.

Pop

ulat

ion

(100

0t)

Exp

loita

tion

Rat

io(%

)

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Procedure of TAC Decision

The procedure is not opened.

TAC sometimes does not based on ABC but other option

The socio-economic consideration is not quantified and unclear

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An proposed procedure of TAC decision

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Success Probability of sustainable management

Success of sustainable fisheries management

Biological success：Maintaining Spawning stock biomass and/or Stock Biomass

Economical Success：Maintaining Net Revenue

Both success is necessary

Suppress of Fishing Pressur

Increase Biological Success

Decrease Economical Success

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Stock with high biomass

Fishing Pressure

Success P

rob

. Proper rangeABC

TAC=

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Stock with low biomass

Fishing Pressure

Success P

rob

.

Econ. Suc. ProbBiol. Suc. Prob.

ABC TAC

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Stock with low demand

Fishing Pressure

Success P

rob

. Proper rangeABCTAC

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Estimating Proper Fishing Pressure

Estimate of Biological Success Probability

Already calculated

Precision should be increase

Estimation of Economic Success Prob.Unclear

Develop the method

Data collection

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Widen the proper area

Increase Biol. Suc. Prob.Care the spawning grounds

Avoid Ocean Pollution etc.

Increase the precision of the stock assessment

Increase Econ. Suc. Prob.Lower the costs

Increase Effectiveness

Find new markets

Added Value, Advertisement

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Stock with low biomass

Fishing Pressure

Success P

rob

.

Econ. Suc. ProbBiol. Suc. Prob.

ABC TAC

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Increasing Success Probability

Fishing Pressure

Success P

rob

.

ABC

TAC=

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ΔBiomass＝Recruitment+Growth

－Catch－Natural Mortality

Net Income＝Unit Price×Catch

－Costs

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Hints for the future research collaboration in fishery

managementin Southeast Asia

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Data Collection

Species Identification

Analysis of the Catch data

CPUE from sampled fishers

Mathematical Analysis

Simulation on Population Dynamics

Reproduction

Feedback control modeling

Presentation tool for stakeholders

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I am very happy if we make collaboration researches and help sustainable fishery in Southeast Asia.