最大持続生態系サービスと 順応的生態系管理 松田裕之（横浜国大）

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最大持続生態系サービスと順応的生態系管理

松田裕之（横浜国大）

H Matsuda & PA Abrams （トロント大）Ecol. Appl. 2006 　 16:225-237

牧野光琢（水産総研セ）・小谷浩示（国際大）5th World Fisheries Congress

http://risk.kan.ynu.ac.jp/matsuda/2008/080527NIE.ppt

2008/3/2 2

今日の話1. 最大持続漁獲量（ MSY) 理論批判2. 順応的生態系管理の限界3. 最大持続生態系サービスの提案

http://risk.kan.ynu.ac.jp/matsuda/2008/080527NIE.ppt

12/6/06 3

Requiem to Maximum Sustainable Yield Theory

• Ecosystems are uncertain, non-equilibrium and complex.

• MSY theory ignores all the three.• Myth #2 MSY theory

guarantees species persistence…

Stock abundance

surp

lus p

rodu

ctio

n

Species Replacement of Pelagic FishesC

atch

in J

apan

(10

00 m

t) AnchovyHorse mackerelsPacific sauryChub mackerelSardine

改定管理方式は順応的管理の先取りだった。 RMP is an AM

0

1

2

0 0.2 0.4 0.6 0.8 1

Relative Stock Size P t/P 0

Unusedresourcemanaged

resource

Protectedresource

Production

Catch quota

Fishing rate

MSY

limit stock level

MSY at 60%,0 catch at 54%

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Unconstrained MSY that maximizes the total yield from the community

(Matsuda & Abrams 2006)

• We choose fishing effort ei independently;

• 6-species systems including 2 prey• random matrix with 50% probabilities;• we seek r having a positive equilibrium;• price p is 0-1 for prey, 0-10 for predators• Unconstrained MSY that may result in

extinction;1 2

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Some resultant biological communities at MSY (Matsuda & Abrams 2006)

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(b)

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(a)

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(c)

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Solution maximizing total yield from community

MSY solution often reduces species and links;

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(d)

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2008/3/2 8

今日の話1. 最大持続漁獲量（ MSY) 理論批判2. 順応的生態系管理の限界3. 最大持続生態系サービスの提案

http://risk.kan.ynu.ac.jp/matsuda/2008/080527NIE.ppt

12/6/06 9

Feedback control in fishing effort is powerful...

Myth #4• Even though the MSY

level is unknown, the feedback control stabilizes a broad range of target stock level .

( )dN f N qENdt

*dE U N Ndt

Stock size N

f(N)

N*N* N*

Stock size Fishing effort

Harvest of prey(Matsuda & Abrams 2008 4th WFC Proceedings)

( )dE

U N Sdt

In the case of feedback control,

Catch of prey will decrease predator, rather than prey

dN/dt=0

dP/dt=0

(1 )1

dN r N P qENdt

fNNK hN

1bfNhN

dP d P Pdt

12/6/06 11

Fishing effort must be controlled by the predator density P

• dE/dt = U(P – Target predator density)• E = E(N, P), E/N > 0, E/P > 0

e.g. E = Etarget (1 + a log NP/NtargetPtarget)

• In this case, feedback control guarantees persistence of the target stock and its predators.

• Adaptive multi-species management is sometimes needed (seek simplicity, but distrust it).

Feedback control with community interactions also result in undesired

outcomes. (M & A unpublished)

r = (0.454,1.059,1.186,0.247,-0.006,-0.028,-0.059,-0.704,-0.308,-0.238)

ii ji j i i

j

dNr a N qe N

dt

A = (aji) =

e9 = 0.1, ei = 0

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42

5 6

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9 10

1. 0.74 0.19 0.31 0. 0. 0. 0. 0.7 0.460.74 1. 0.87 0.08 0.46 0.66 0.48 0.73 0.84 0.0.19 0.87 1. 0.96 0.08 0.14 0.83 0. 0. 0.680.31 0.08 0.96 1. 0. 0. 0. 0.28 0. 0.880. 0.46 0.08 0. 0.1 0. 0. 0.92 0.15 0.840. 0.66 0.14 0. 0. 0.1 0.01 0. 0.5 0.690. 0.48 0.83 0. 0. 0.01 0.1 0.56 0. 0.0. 0.73 0. 0.28 0.92 0. 0.56 0.1 0.28 0.0.7 0.84 0. 0. 0.15 0.5 0. 0.28 0.1 0.0.46 0. 0.68 0.88 0.84 0.69 0. 0. 0. 0.1

Feedback control may result in extinction of other species (sp. 6).

de9/dt = u(N9-N9*)ratio

2008/3/2 14

今日の話1. 最大持続漁獲量（ MSY) 理論批判2. 順応的生態系管理の限界3. 最大持続生態系サービスの提案

http://risk.kan.ynu.ac.jp/matsuda/2008/080527NIE.ppt

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生物多様性Biodiversity

生態系機能Ecosystem functions

地球環境変化 Gobal change

生態系サービス Ecosystem services

人間の福利 Human well-being

持続可能性＝次世代の人間が生態系サービスを享受できるよう、自然を守る( 米生態学会委報告 1996)(MA2005)(MA2005)

http://risk.kan.ynu.ac.jp/matsuda/2008/080223.ppt

文化的サービス

供給サービス

調整サービス

なぜ自然を守るのか ?

2008/3/2

支持サービス

生態系サービスと人間の福利（ MA 2005 より）

安全保障•個人の安全•資源利用の保障•災害からの保障

人間の福利の構成要素

生存権の基盤•適切な生活条件•十分な栄養ある食料•住居•生活用品の提供

健康•活力•快適さ•きれいな空気と水の提供

よい社会関係•社会の連帯感•互恵•扶助の能力

選択と行動の自由

•

一人一人がやりたいこと、大切にし

たいことを達成する能力

供給サービス•食料•淡水•木材と繊維•燃料 その他

•

支持サー

ビス　

栄養素の循環、

土

壌形成、

一次生産、その他

調整サービス•気候調節•洪水制御•疾病制御•水質浄化 その他

文化的サービス•審美的•精神的•教育的•娯楽的 その他

生態系サービス

低い中間高い

弱い中間強い

矢印の色社会経済的認知度

矢印の太さ繋がりの強さ　　　　

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生態系サービスの価値

• 生物資源　生物資源　農林水産物 農林水産物 約 140 兆円 / 年

• 生態系生態系 service service 物質循環 物質循環 約 1700 兆円 / 年

• 資源価値＜＜生態系サービス• 漁場の自然価値＞漁業補償

2008/3/2

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Risk of human lives by climate change

Parry et al., (2001) IPCC 報告書

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Effect on ecosystems by climate chage

Hare, W. L. (2003). Assessment of Knowledge on Impacts of Climate Change – Contribution to the 　 Specification of Art. 2 of the UNFCCC.

http://www.wbgu.de/wbgu_sn2003_ex01.pdf.

Global mean temperature increase above pre-industrial

Ecosystem services V(N, C)

• V(N, C) = Y(C) – cE + S(N)

• Provisional Service (Fisheries Yield) … Y(C) • Fishing Cost… cE• Utility of standing biomass… S(N) • C… catch; E… fishing effort; N… stock biomass

2008/3/2 20(Matsuda, Makino, Kotani, in press)

Stock abundance N

Regulating services S(N)= SN2/(B2+N2)

(S, B) = (100,10)

(S, B) = (50,50)

2008/3/2 21(Matsuda, Makino, Kotani, in press)

Mathematics

• Stock dynamics … dN/dt = (r – aN)N – C,• Catch and yield … C = qEN, Y(C) = pqEN,• Regulating service … S(N) = SN2/(B2+N2),• Equilibrium … N*(E) = (r – qE)/a• Service at N* … V*(E) = pqEN* – cE + S(N*)• Optimal effort Eopt satisfies that V*/E = 0

• Maximum Sustainable Ecosystem Service Eopt = (pqr – ac)/2pq2

2008/3/2 22(Matsuda, Makino, Kotani, in press)

Fishing effort E

Maximum Sustainable Ecosystem Service

(S, B) = (100,10)

(S, B) = (50,50)

(S, B) = (0,-)

2008/3/2 23(Matsuda, Makino, Kotani, in press)

Control rules

Constant catch

ABC rule

Constant escapement

MSY vs MSES with uncertainties(Y*,V*) = (77.6 ,165.7) (Y*,V*) = (43.3, 216.4)

2008/3/2 25

fishing effort stock abundance Catch

(Matsuda, Makino, Kotani, in press)

MSES from food webs

• Community dynamics …dNi/dt = (ri + ajiNj – qiEi)Ni

• Yield from foodweb… Y(E) = Ei(piqiNi – ci)

• Total ecosystem services...V(E) = Y(E) + Si(Ni)

• Si(Ni) = SiNi

2/(Bi2+Ni

2)

• We obtained EMSES ↑ Y(E) and EMSY ↑V(E)

2008/3/2 26(Matsuda, Makino, Kotani, in press)

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(h)(g)(f)

2008/3/2 27(Matsuda, Makino, Kotani, in press)

Resultant food webs and fishing efforts from 1000 randomly constructed six species systems.

No. of species

No. of extant species using MSY policy

No. of exploited species using MSY policy

No of extant species using MSES policy

No of exploited species using MSES policy

0 0 0 0 9

1 0 204 0 96

2 206 792 13 318

3 531 4 43 337

4 236 0 31 201

5 25 0 8 35

6 2 0 905 4

(Matsuda, Makino, Kotani, in press)

MSES saves fishing efforts

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Ban-on-Fishing

(Matsuda, Makino, Kotani, in press)

Conclusion

• Responsible fisheries may play roles of umbrella species that use a small part of healthy ecosystem services, and give many data of utilized resources…

• Fishing efforts that maximizes the total ecosystem services are usually much smaller than those for maximum sustainable yield.

2008/3/2 30(Matsuda, Makino, Kotani, in press)