classic msy theoryclassic msy theory requiem...
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Classic MSY theoryClassic MSY theory
400iv
ety
200
300
odu
cti
100
200
lus
pro
0
100
surp
l
0 500 1000
stock biomass
Requiem to MaximumRequiem to Maximum Sustainable Yield Theoryy
• Ecosystems are uncertain, non-equilibrium and complexand complex.
• MSY theory ignores all the three.• Does MSY theory
guarantee species 120
nguarantee species persistence?
No!! 6080
100生産力 ro
duct
ion
- No!!2040
力
urpl
uspr
200 400 600 800 1000
親魚量Stock abundance
su
The tragedy of the commons(Hardin 1960)
• Open access fisheries promotes overexploitationEEZ b UNCLOS (1996)• EEZ by UNCLOS (1996)
dR/dt = (K – E1 – E2 – R) RR k i E E fi hi ff f 2 fi hR:stock size; E1, E2 :fishing effort of 2 fishersEquilibrium R = K – E1 – E2
Catch F1=RE1=(K – E1 – E2)E1 F2=(K – E1 – E2)E2
Nash sol. ∂F1/∂E1= (K – 2E1 – E2) = 0, ∂F2/∂E2 = 0F1=F2=K2/9 at E1 = E2 = K/3, R = K/3 < RMSY
3
The tragedy of the commons④Try by yourself ④The tragedy of the
Equilibrium N 333 Equilibrium N 333Equilibrium N 333 Equilibrium N 333
e Catch e Catch
A 4 1,333.3 A 4 1,333
B 4 1,333.3 B 4 1,333
Total 8 2 667 Total 8 2 667Total 8 2,667 Total 8 2,667r= 12 K= 1000
1.Moderate e at MSY 2.Equal division for both profit 3.If A do cheating, B lose 5.If A do cheating more, both
ABC decision ruleABC decision rule
cien
t Fco
effic
ishi
ng
Estimate of stock biomass N
Fi
Estimate of stock biomass N
A simulation result of fisheries management
Nt
Ct
nt F
omas
s m
ount
oeffi
cein
ock
bio
atch
am
hing
co
Sto Ca
Fish
Year tYear t
Species replacement of plankton-feeding pelagic fish in Japanese waters
AnchovyJack mackerelPacific sauryon
s)
Pacific sauryChub mackerelJapanese sardine
1000
tond
ings
(La
n
Year
“Aging” of Japanesesardine during 1988 to 1991
Estimate of stock abundance of Japanese sardine in Kuroshio region( illi t ) 0 t 5
http://abchan.job.affrc.go.jp/digests15/details/1503.pdf
(million tonnes), age 0 to >5 yrs.
Japan Government agreed overfishingJapan Government agreed overfishingof sardine (TAC > ABC >> catch)( )
• Pacific saury Japanese sardine
サンマ イワシ
80
90
100
トン
)
サバ
60
70
80
トン
)
サンマ
70
80
ン)
マイワシ
000t
ons)
ン)
50
60
70
80
漁獲
量(万
40
50
60
漁獲
量(
万ト
40
50
60
漁獲
量(万
トン
catc
h(10
,0
獲量
(万
ト
20
30
40
AC
,A
BC
,漁
20
30
40
AC
,A
BC
,漁
20
30
40
TA
C,
AB
C,
漁
AC
,act
ual c
C,T
AC
,漁0
10
1997 1999 2001 2003
TA
0
10
1997 1998 1999 2000 2001 2002 2003
TA
0
10
1997 1998 1999 2000 2001 2002 2003
T
AB
C,T
A
AB
1997 1998 1999 2000 2001 2002 2003 1997 1998 1999 2000 2001 2002 2003
Recruitment of chub mackerelRecruitment of chub mackerel temporally fluctuated
=recruitment/spawning stock
Large year class appeared twicepp
Stock of Kuroshio Region
Overfishing of immature chub mackerelOverfishing of immature chub mackerel70年代 80年代 90年代 93年以降
尾数 65.0% 60.0% 87.0% 90.6%
4
lion)
0 1 2 3
4 5 6+
2
3
mbe
rs (b
ill 4 5 6+
1
2
ch i
n nu
m
d
0
1
Cat
c
01970 1975 1980 1985 1990 1995
If fishers conserve immatures like 1970 80s
120.0 10.00
s)
If fishers conserve immatures like 1970-80s
80.0
100.0
6 00
7.00
8.00
9.00
△(m
illio
nto
ns
mill
ion t
ons)
◆
40.0
60.0
3.00
4.00
5.00
6.00
Recru
itm
ent△
ng
biom
ass(
m0.0
20.0
0.00
1.00
2.00
1999 2004 2009 2014 2019 2024 2029
Cat
ch●
、
Spa
wni n
1999 2004 2009 2014 2019 2024 2029
Year
If fishers continue the overfishing of
immatures like 1990s
Risk assessment of stock recovery plan (“SMwE Operating Model”)
• Start age structure of the current stock; • Future RPS (αt) is randomly chosen fromFuture RPS (αt) is randomly chosen from
the past 10 years estimates of RPS. (include process errors)(include process errors)
• N0,t = SSBt αt/(1+β SSBt)0,t t t t
• Na+1,t+1 = Na,t exp[-M-Fa] (a=0,1,...5, “6+”)C N e M/2 F• Ca,t = Na,t e-M/2 Fa wa
12/6/06 13Kawai,…,Matsuda, Fish. Sci. 2002
Revised Management Procedurein International Whaling Commission
初期管理資源Initial stockquota
と生
産量
初期管理資源
持続的利用
Initial stock
Sustainable useCatc
h q
漁獲
圧と
保護対象
Sustainable useProtected stock
vit
y a
nd
0 1
漁
54%K KProducti
v
0 1相対資源量
Bayesian approach for measurement uncertainty
Relative stock size
KP
2006/5/22 14
Bayesian approach for measurement uncertainty
Yes it should have recoveredYes, it should have recovered. (Kawai et al 2002)
Actual stock abundance tons
)m
illio
n
stock if saving immature
mas
s (
ck b
iom
Sto
Probability that the stock recoversProbability that the stock recovers above 1 million tons (Kawai et al 2002)
百万トトン資源源回復確確率
We need another two decades for recovery
Management Strategy Evaluation(MSE)Simple version
0 61000
0 5
0.61000
t0.40.50.61000
ent
ass,
…
0.3
0.4
0.5
500 ffic
ient
ass,
har
vest
0.20.30.4
500
coeffic
ie
k bi
om
a
0.1
0.2
fish
ing
coe
stock
biom
00.1
00 50 sh
ing
c
stoc
year00
0 20 40 60
0 50 fisyear
year
A iti f l diAge composition of landings between Japan and north Atlantic
North Atlantic Fishery hasNorth Atlantic Fishery has IQ (individual quota)
Japan is still “Olympic” competition
ドーナツの内側から
North Atlantic2000-2004North Atlantic2000 2004
Japan 1970
Japan 1995
http://www.ices.dk/marineworld/fishmap/ices/pdf/mackerel.pdf
Ecosystem services V(N, C)
100120
ctio
n“Maximum Sustainable EcosystemServices” = maximizing V
V(N C) Y(C) + S(N) 406080
100生産力 s
prod
uMaximum Sustainable Yield= maximizing Y(C)
• V(N, C) = Y(C) + S(N) • N = K(1 – qE/r) 200 400 600 800 1000
2040
surp
lus
( q )• C = qEN
P i i l S i (Fi h i Yi ld) Y(C)
200 400 600 800 1000
親魚量Stock abundance
• Provisional Service (Fisheries Yield) … Y(C) • Utility of standing biomass… S(N)Utility of standing biomass… S(N) • C… catch; E… fishing effort; N… stock
bibiomass• K… Carrying capacity, r…Malthusian parameter, q…
t h bilit
Paradigm Shift from MSY to MSESParadigm Shift from MSY to MSES
M i S t i bl120
Maximum Sustainable Ecosystem Services
s
80
100 Maximum Sustainable Yield
serv
ices
vice
s
60
80
UnsustainableFi h i
stem
sYi
eld
ng S
erv
40No take zone
Fisheries e
cosy
sher
ies
egul
atin
20
Tota
l=
Fis
+ R
e
0
0 20 40 60 80 100 1202008/3/2 20Fishing effort
Catch and mean trophic level in Japan We can use >2 million tons of pelagic fi h t i bl i J EEZfishes sustainably in Japanese EEZ.
• But demand-supply mismatch: overfishing and underuse.pp y g
Source: Fisheries Research Agency, Japan
JC Castilla氏
Chile encourages artisanal fisheries
18009000
A1000
)
1000
) CHILE
○企業体漁業I
5 miles
1000
1200
1400
1600
5000
6000
7000
8000 AArtisan & Industrial (includes algae)IndustrialArtisan (includes algae)
FAL
c to
ns
1*
e ( U
S$
II
III
IVV
400
600
800
1000
2000
3000
4000
5000
ng (m
etric
ort
Valu
e
RMV
VIVII
VIIIIXX
1970 1975 1980 1985 1990 1995 2000 20050
200
0
1000
Land
in
Expo
XI
5 miles AEZ = Artisan Exclusive Zone (ca. 27.000 km2)
▼零細漁業XII
Territorial User Rights for Fishers (TURFs) are
ll t d t iti
•MEABRs = Management and E l it ti A f
23
allocated to communities with MEABRs.
Exploitation Areas for Benthic Resources
Super-Malthusian Increase of populationand per capita energy consumption
World Population (0.1 billion)
Energy Consumption (1000kcal/day/person)
1
Year (A.D.)
Data: Earl Cook (1971) and Joel E. Cohen (1995)
Decreasing Ecological footprint,Increasing biological capacity with
WWF 2002
Increasing biological capacity with..ha
)Biodiversity conservation
rint (
gh Biodiversity conservation
Built-up landEnergyfo
otpr
gyFisheriesForestryGrasslandog
ical
GrasslandAgriculture
Ecol
o
Biologicalcarrying capacitycapacity
Ranking of per capita EFRanking of per capita EF
WWF Living Planet Report 2004
Global Ecological Footprinthttp://www.ecofoot.jp/
Our life step upon the size of 2 4 the Earth we have to goal2.4 the Earth, we have to goal
to size of one that.
WWF 2004
Measuring natural valueg(Costanza et al 1997)
•• ProvisioningProvisioning == agricultural fisheryagricultural fisheryProvisioningProvisioning = = agricultural, fishery agricultural, fishery and forestry products ca. 14 billion and forestry products ca. 14 billion
//yen/yearyen/year
•• RegulatingRegulating == material circulation camaterial circulation caRegulatingRegulating material circulation ca. material circulation ca. 170 billion yen/year170 billion yen/year
• Provisioning service << Regulating serviceservice
• Natural value of fishing ground > f f
28
compensation for fishers
biomePrice(US$/h )
area (km2)vaues(MUS$/ )
biome$/ha)
area (km2)(MUS$/year)
desert 0 215900 0tundra 0 43300 0I /R k 0 164000 0Ice/Rock 0 164000 0Open ocean 491 3320000 163,012marine shelf 2,222 266000 59,105
/ l d 2 871 441800 126 841grass/rangelands 2,871 441800 126,841
temperate/boreal forest 3,013 300300 90,480
lakes/rivers 4,267 20000 8,534a es/ ve s , 6 0000 8,53tropical forest 5,264 125800 66,221cropland 5,567 167200 93,080urban 6,661 35200 23,447, ,
swamps/flood plain 25,682 6000 15,409
tidal marsh/mangroves 193,845 12800 248,122
l f 352 249 2800 98 630
R. Costanza et al. / Global Environmental Change 26 (2014) 152–158
coral reefs 352,249 2800 98,630
Capture fisheries production in marine areasCapture fisheries production in marine areas(FAO, SOFIA2006)
• Landing is decreasing in Northwest Atlantic, but...
• It is increasing in Western Central Pacific!
• SOFIA 2014
Changes in the Marine Trophic Index
GBO2Pauly D., Watson R. Phil. Trans. R. Soc. B;2005;360:415-423
Difference in fish consumption b t t i
Total Fish Consumption (Metric Tons) Low Value Food Fish as a Share of Total FishConsumption
After Doug Beardbetween countries
120000
140000Consumption
80
90
80000
100000
Con
sum
ed
50
60
70
Developing World
40000
60000
ric T
ons
C
30
40
50
Perc
ent
Developed World
World
20000
40000
Met
r
10
20
30 World
01960 1980 2000 2020 2040
Year
01970 1980 1990 2000 2010 2020 2030
Year
From Delgado et. al. 2002, Fish to 2020, Table E.14
From Delgado et. al. 2002, Fish to 2020, Table 3.3
国際的に批判され始めた海洋栄養段階
Bi di it i di t id it l i d th t t f th l t
12月速報
Biodiversity indicators provide a vital window on the state of the planet, guiding policy development and management1,2. The most widely adopted marine indicator is mean trophic level (MTL) from catches, intended to detect shifts from high-trophic-level predators to low-trophic-intended to detect shifts from high trophic level predators to low trophiclevel invertebrates and plankton-feeders3–5. This indicator underpins reported trends in human impacts, declining when predators collapse (‘‘fishing down marine food webs’’)3 and when low-trophic-level fisheries
d (‘‘fi hi th h i f d b ’’)6 Th ti i th texpand (‘‘fishing through marine food webs’’)6. The assumption is that catch MTL measures changes in ecosystem MTL and biodiversity2,5. Here we combine model predictions with global assessments of MTL from catches trawl surveys and fisheries stock assessments7 and find thatcatches, trawl surveys and fisheries stock assessments7 and find that catch MTL does not reliably predict changes in marine ecosystems. Instead, catch MTL trends often diverge from ecosystem MTL trends obtained from surveys and assessments. In contrast to previous findings f id d li i t h MTL3 b t i i t hof rapid declines in catch MTL3, we observe recent increases in catch,
survey and assessment MTL. However, catches from most trophic levels are rising, which can intensify fishery collapses even when MTL trends are stable or increasing To detect fishing impacts on marine biodiversityare stable or increasing. To detect fishing impacts on marine biodiversity, we recommend greater efforts to measure true abundance trends for marine species, especially those most vulnerable to fishing. Adoption of an ecosystem approach to fisheries