キューバ海域に生息するタイマイの順応的管理

An Adaptive Management for
Hawksbill Turtles
Shin-ichi EBINA & Hiroyuki MATSUDA
（Ocean Research Institute, Univ.Of Tokyo）
Thank to Grahame Webb (Australia) and
Mari Kobayashi (Japan), Elvira Carrillo
(Cuba)
10/1/2015
1
新プロ DOBIS
変動班
管理と保全の変動モデル
松田裕之・立川賢一・蝦名晋一・森光代
（海洋研・資源解析）
今年の研究：不確実な情報しかない「希
少」海産生物の管理手法
クロミンククジラの資源量推定に及ぼす観
察員経験年数の効果（ＩＷＣロンドン）
キューバのタイマイの順応的管理によるリ
スク評価（SeaStar2000タイシンポ）
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2
Hawksbill Turtles Harvest in Cuba
399/yr
4744/yr
Cuba CITES Proposal (2000)
Is 90% catch reduction enough for conservation?
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3
CITES Proposals by Cuba
Down-listing from Appendix I to II, and
permit export Hawksbill Turtles Products
once to Japan
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4
Controversy on CITES criteria
CITES Fauna & Flora Chairs: not
be included in Appendix I when the
risk of the listing … outweigh the
conservation benefit of the listing,
IUCN: Listing of Endangered
species in Appendix I is always
benefit for conservation.
See http://cod.ori.u-tokyo.ac.jp/~matsuda/2001/whale.html
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5
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1458000/1458234.stm
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Problems of Hawksbill Turtle
Mixture of other endangered stock
(haplotypes of Cuban HT is different from
that of other Caribbean HT, Koike’s group)
Bycatch ca700 juveniles and adults
Large uncertainty in life history,
absolute population size, and age
identification.
We need adaptive management
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What is Adaptive Management?
see also http://www.for.gov.bc.ca/hfp/amhome/AMDEFS.HTM
assess problems
To control management
policy adjusted to monitoring
data (adaptability),
Adjust
design
To include new knowledge
flexibly (accountability),
implement
Evaluate
To make consensus by
various stakeholders,
monitoring
To write falsifiable objects.
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RMP in Whales
(Revised Management Procedure)
To monitor stock size by research vessels
Pt+1 = Pt - Ct+1.4μPt[1 - (Pt/P0)2]
To decide catch limit Lt (> Ct) by
Lt = 3μ(Pobs,t/P0 - 0.54)Pobs,t
Pobs,t = bPt [1+N(0,s)]
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Feedback Management for sika
deer in Hokkaido, Japan
To avoid overabundance
and extinction risk,
To seek sustainable deer hunting,
To monitor population size
To catch females when %P>25%,
males when 5%<%P<25%
http://www.hokkaido-ies.go.jp/HIESintro/Natural/ShizenHP2/SIKA/DTdeerHP.htm
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The age of overabundance will finish!
Female hunting
Management Program started in 1998
95% CI
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1993
11
Merits of Adaptive Management
To clarify goals and objects,
To monitor population trends,
To change catch with recent stock
estimates,
Risk assessment based on a population
dynamic model with uncertainties,
To test interim assumptions and models
and to encourage further research.
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Proposal of Goal and Objects
for HT management
Sustainable use and population
conservation under uncertain scenarios,
Increase of catch quota if estimated
female adults are more than …,
No catch if nested female adults (>50cm
SCL) are fewer than 500,
Regulation of by-catch if …
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Data about Hawksbills in Cuba
■growth rate and maturing rate at each size-class
(from Ohtaishi(unpublished), Moncada et al.(1999) and Pilcher et al.(1999))
SCL
growth rate
(cmSCL/y)
maturing
rate(%)
420
2030
3040
4050
5155
5660
6165
6570
7175
7680
80-
9.4
6.1
5.0
4.3
3.9
3.7
3.5
3.4
3.2
3.1
2.9
mature→ 0.1
0.1
0.1
0.1
0.1
0.1
0.1
4
7
11
19
46
100
0
0
0
0
4
traditional harvesting
by-catch:A
10/1/2015
by-catch:B
14
Population Dynamic Model
(Determinate Growth)
FN (t ) I
G
N (t ) J
G
J
N
(
t
)
G
J
G
 J
G
J
 J
G
G
N (t ) J
G
J

G
N (t ) J
G
J
N
(
t
)
G
J
G
N (t ) J
G
J

G
J
G
 J
G
J
N
(
t
)
H K
1,1
1, 2
1, 3
1,11
2 ,1
2 ,2
2 ,3
2 ,11
10/1/2015
F0.38
G
0.52
G
G
G
G
G
G
G
G
0
G
G
G
G
G
G
G
H
0
0
0.33
0
 0.27 0.59
0
1, 3
O

O
016
.
0.29
0
1,11
0
O
0
O
0

0

O
1,1
1, 2
O
0.56 0.43
I FN (t  1) I
JJ GN (t  1) J
J
JJ G
N
(
t

1
)
G
J
G
J

JJ G J

G
JJ GN (t  1)JJ
G
J
JJ GN (t  1) J
G
J
N
(
t

1
)
JJ G J
G
N (t  1) J
JJ G  J
G
J
JJ G  J
G
J
0.83KH
N (t  1)K
0 0  0.59 0.59
O
0.83
2 ,2
2 ,3

0.38
2 ,1
0.83
2 ,11
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Life History Parameters for
Hawksbills in Cuba
Mortality Rate
○After 1 year of age：0.1
●Harvesting rate：depending on catch data
○Hatchling to 1-year-old：99.0% (Webb et al., in comm.)
Fertility
●hatchling rate：0.69 (Moncada et al.,1999)
●proportion sex ratio：0.768 (Carrillo et al.,1999)
●nesting interval：2.42(yr) (Hoyle and Richardson,1993 etc.)
●clutches/season：2.0 (Moncada et al.,1999)
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Simulation
Initial population size is 50,000-110,000
Including uncertainty to each parameter
Assume facing bad environment every
ten years on average
Changing annual survival rates
Hatchling rate：0.69 to 0.6
Hatchling to 1-year-old：0.01 to less than 0.01
We repeated calculation 300? times
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Simulations under constant
500 catch
8000
300
6000
(thousands)
number of females
10000
4000
2000
200
year
2000
2020
2040
2060
2080
2100
100
year
2000 2020 2040 2060 2080 2100
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Simulations under adaptive
management
12000
10000
300
8000
(thousands)
number of females
14000
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6000
4000
2000
200
year
2000
2020
2040
2060
2080
2100
100
year
2000 2020 2040 2060 2080 2100
19
Risk of exploitation bans under
the adaptive management
>?% with the next 1 century
No extinction over 300 simulated
runs
Under the pessimistic assumptions
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Summary
Adaptive management is robust,
Monitoring is indispensable
To examine detail biological data
To get the trend of population size
Consistent method and effort! Or
Record survey efforts and methods!
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来年度の課題
個体群管理から生態系管理へ
勝川俊雄・木村紀雄
Ecosimで得た時系列と順応的管理
Ecosimの改良（群集・進化生態学の知見）
特に、vulnerabilityとMixed Trophic Impact
水圏群集生態学の新たな展開
松田裕之・中嶋美冬
魚の左右性の群集動態と進化機構の解明
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What Remains To Be Done
Confronting model to the data we have
already gotten from literatures
Running some simulation under some
other scenarios
slower/faster-growing assumptions
fewer/-more initial population size
more rapidly/slowly maturing assumptions
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Thank you!!
Welcome to ORI!
Especially for those who
like to apply adaptive
management to stocks in
your country.
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Does Sustainability Require
No-catch? (IWC/SC London 2001)
Even under constant 150 annual catch,
Southern Hemisphere minke whale might
go extinct within the next 1000 years.
If 0 catch at lower stock level than 10,000
whales, the mean extinction time is far
too long (1045 years)
Extinction risk assessment is still
important for conservation.
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