Michael Melnychuk, Tim Essington, Olaf Jensen, Trevor Branch, Ana Parma, John Pope, Tony Smith,
Jason Link, Selina Heppell, Steve Martell
Can fisheries under catch shares
better track management targets ?
Pew Charitable Trusts WebinarNovember 3, 2011
0
25
50
75
100
125
150
175
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000N
umbe
r of c
atch
sha
re fi
sher
ies
Year of catch share implementation
0255075
100125150175 South America
South Africa
Europe
U.S. W coast/Alaska
U.S. E coast
Canada W coast
Canada E coast
Australia
New Zealand
0255075
100125150175
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
Year of catch share implementation
Year of fishery development
Catch shares → Allocation of quota to individuals such that competition among individuals is reduced
Ŷ Catch shares
Ŷ Partial catch shares
Ŷ Quota only
Ŷ Effort regulations
0 50 100 150
Benthic fishBethopelagic fish
Pelagic fishReef-associated fish
Invertebrates
Number of stocks in analyses
0
30
Alaska, U.S.
0
30
Australia
0
30
60New
Zealand
0
30
East coast Canada
0
30
West coast Canada
0
30
Europe
0
30
SouthAfrica
0
30
South America
0
30
Northeast & mid-Atlantic coast, U.S.
0
30
S. Atlantic coast & Gulf
of Mexico, U.S.
0
30
West coast U.S.
ŶC
atch
sha
res
ŶP
artia
l cat
ch s
hare
s
ŶQ
uota
onl
y
ŶE
ffort
regu
latio
ns
050
100
150
Ben
thic
fish
Bet
hope
lagi
c fis
hP
elag
ic fi
shR
eef-
asso
ciat
ed fi
shIn
verte
brat
es
Num
ber o
f sto
cks
in a
naly
ses
030
Ala
ska,
U
.S.
030
Aus
tralia
03060N
ew
Zeal
and
030
Eas
t coa
st
Can
ada
030
Wes
t coa
st
Can
ada
030
Eur
ope
030
Sou
thA
fric
a
030
Sou
th
Am
eric
a
030
Nor
thea
st &
m
id-A
tlant
ic
coas
t, U
.S.
030
S. A
tlant
ic
coas
t & G
ulf
of M
exic
o, U
.S.
030Wes
t coa
st
U.S
.
2000 – 2004
Do catch share fisheries better track management targets than fisheries not under catch shares ?
targets: annual quota (C/Q)exploitation rate target (F/Ftarget)
biomass target (B/Btarget)
Hypotheses:
Adherence to targets: catch shares > quota only > effort controls
Strength of response: C/Q > F/Ftarget > B/Btarget
0.02
0.03
0.04
0.05
0.06
0.07
1980 1985 1990 1995 2000 2005
0.5
0.75
1
1.25
1.5
1980 1985 1990 1995 2000 2005
Target F
F
FF
: Fta
rget
4 metrics:
Mean
SD(target)
Minor exceedance
Major exceedance
0 1 2 3 4 5 6 70
2040
6080
100
0 1 2 3 40
2040
6080
100
0 1 2 3 4 5 6 705
1015202530
0 1 2 3 405
1015202530
0 1 2 3 4 5 6 70
10
20
30
40
0 1 2 3 40
10
20
30
40
0 2 4 60
20406080
100
0 1 2 3 40
20406080
100
0 2 4 605
1015202530
0 1 2 3 405
1015202530
0 2 4 60
10
20
30
40
0 1 2 3 40
10
20
30
40
Summary of response variables
C/Q
n = 259 stocks
F/Ftarget
n = 172
B/Btarget
n = 205
Freq
uenc
y
0 2 4 60
20406080
100
0 1 2 3 40
20406080
100
0 2 4 605
1015202530
0 1 2 3 405
1015202530
0 2 4 60
10
20
30
40
0 1 2 3 40
10
20
30
40
Mean C/Q Mean F/Ftarget Mean B/Btarget
Variables of interest
Catch control type
Other covariates accounted for:
Region
Taxonomic/habitat-
association
Year of fishery
development
Average catch
Lmax
Propensity for being under catch
shares
Responses Predictors
3 ratios with management targets:
Catch/quota
F/Ftarget
B/Btarget
4 metrics:
Mean
SD(target)
Minor exceedance
Major exceedance
X
-6 -4 -2 0-6 -4 -2 0-3 -2 -1 0-3 -2 -1 0
Catch sharesPartial catch shares
Quota only
Average catch
Development year
Lmax
Propensity score
Mean C/Q SD(target C/Q) Small overages (10%)
Large overages (25%)
Mean C/Q SD(target C/Q) Minor (10%) overages
Major (25%) overages
C/Q analysis
Catch sharesPartial catch shares
Quota only * *
-6 -4 -2 0-6 -4 -2 0-3 -2 -1 0-3 -2 -1 0
Catch sharesPartial catch shares
Quota only
Average catch
Development year
Lmax
Propensity score
Mean C/Q SD(target C/Q) Small overages (10%)
Large overages (25%)
Coefficient estimate
-3 -2 -1 0 1-3 -2 -1 0 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean F/F ref SD(target F/F ref)Minor overfishing
(10%)Major overfishing
(50%)
Catch sharesPartial catch shares
Quota onlyEffort regulations
Mean F/Ftarget SD(target F/Ftarget)Minor (10%)
over-exploitationMajor (50%)
over-exploitation
-5 -3 -1 1-5 -3 -1 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean F/F referenceSD(target F/F reference )
Minor overfishing (10%)
Major overfishing (50%)
*-3 -2 -1 0 1-3 -2 -1 0 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean F/F ref SD(target F/F ref)Minor overfishing
(10%)Major overfishing
(50%)
-3 -2 -1 0 1-3 -2 -1 0 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean F/F ref SD(target F/F ref)Minor overfishing
(10%)Major overfishing
(50%)
F/Ftarget analysis
Coefficient estimate
-3 -2 -1 0 1-3 -2 -1 0 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean B/B ref SD(target B/B ref)Minor depletion
(10%)Major depletion
(50%)
Catch sharesPartial catch shares
Quota onlyEffort regulations
Mean B/Btarget SD(target B/Btarget)Minor (10%)
depletionMajor (50%)
depletion
-3 -2 -1 0 1-3 -2 -1 0 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean B/B ref SD(target B/B ref)Minor depletion
(10%)Major depletion
(50%)
Coefficient estimate
B/Btarget analysis
Summary
• Compared to non-catch shares, catch share fisheries had:
• less variability in C/Q
• less frequent (major) overfishing
• Effects of both quota management and catch shares
• Catch shares are one of many possible tools that can be used to help meet
management objectives
• Next step: what particular aspects of catch share systems tend to lead
to the outcomes we’ve observed ?
Thank you:
Data collection: Kate Stanton, Rachel Finley, Jordan Watson
Funding: Lenfest Ocean Program
RAM Legacy database: Dan Ricard and all contributors
Interviews: U.S. – Alaska: J. DiCosimo, J. Heltzel, M. Fina, S. Hare, S. Kelley, J. Regnart; U.S. – W Coast: J. DeVore, M. Burner, C. Niles, I. Stewart; U.S. – NE/Mid-Atl. Coast: C. Legault, T. Chute, D. Hart, J. Idoine, G. Shepherd, B. Beal, N. Meserve, K. Taylor, B. Spear, D. Boelke, T. Hoff, K. West, J. McNamee; U.S. – SE Coast/G. Mexico: J. McGovern, P. Hood, A. Strelcheck, S. Gerhart, J. Kimmel, J. Smith; Canada – W Coast: A. Keizer, B. Ackerman, W. Li Ou, P. Ridings, J. Rogers, J. Schweigert, E. Wylie, M. James; Canada – E Coast: P. Cahill, V. Docherty, J. Hansen, D. Coffin, M. Baker, D. Ball, H. Bishop, J. Buie, S. Campana, G. Chouinard, J. Conlin, P. Couillard, A. Frechet, J. Gaudette, C. Hendry, P. Koeller, M. LeCouffre, L. Legere, D. Lemelin, B. Lester, C. MacDonald, B. Morin, M. Moriyasu, D. Pezzack, D. Roddick, A. Rumbolt, T. Siferd, J. Simon, S. Smith, G. Stevens, H. Stone, C. Waters, R. Federizon; Europe: J. Sigurjónsson, J. Horwood, B. Deas, A. LeGarrec, C. Olesen, M. Anderson, M. Welvaert, G. van Balsfoort, P. Breckling, N. Holdsworth; Australia: C. Dichmont, N. Klaer, G. Tuck, S. Wayte, S. Auld, S. Gaddes, S. Koh, S. Weekes, B. Taylor, K. Crosthwaite, T. Ward, C. Gardner; New Zealand: D. Foster, D. Sykes, G. Clement; Argentina: J. Hansen, A. Giussi, M. Renzi; South Africa: A. Brandao, D. Butterworth, S. Halloway, S. Johnston, C. de Moor, R. Rademeyer, G. Maharaj, R. Bross, A. Badenhorst.
0.0 0.5 1.0 1.5 2.0
0
10
20
30
40
0
1
2
3Catch shares
0.0 0.5 1.0 1.5 2.0
0
10
20
30
40
0
1
2
3Partial catch shares
0.0 0.5 1.0 1.5 2.0
0
10
20
30
40
0
1
2
3Quota only
0 1 2 3
0
10
20
30
40
0
2
4
6
8Catch shares
0 1 2 3
0
10
20
30
40
0
2
4
6
8Partial catch shares
0 1 2 3
0
10
20
30
40
0
2
4
6
8Quota only
▬ Alaska, U.S.
▬ West coast, U.S.
▬ West coast, Canada
▬ East coast, Canada
▬ Europe
▬ Australia
▬ New Zealand
▬ Other
Probability density
Mean C/Q SD(target C/Q)
Catch/quota ratios
n = 130
n = 41
n = 88
▬ F
requ
ency
0 1 2 3 4 5 6 70
5
10
15
0.0
0.5
1.0
1.5Catch shares
0 1 2 3 4 5 6 70
5
10
15
0.0
0.5
1.0
1.5Partial catch shares
0 1 2 3 4 5 6 70
5
10
15
0.0
0.5
1.0
1.5Quota only
0 1 2 3 4 5 6 70
5
10
15
0.0
0.5
1.0
1.5Effort control
0 1 2 3 40
5
10
15
0.00.51.0
1.52.02.5Catch shares
0 1 2 3 40
5
10
15
0.00.51.0
1.52.02.5Partial catch shares
0 1 2 3 40
5
10
15
0.00.51.0
1.52.02.5Quota only
0 1 2 3 40
5
10
15
0.00.51.0
1.52.02.5Effort control
▬ Alaska, U.S.
▬ West coast, U.S.
▬ NE & mid-Atl., U.S
▬ Europe
▬ New Zealand
▬ Other
Probability density
Mean F/Ftarget SD(target F/Ftarget)
0 2 4 6024681012
0. 00. 51. 0
1. 5Cat ch s hare s
0 2 4 6024681012
0. 00. 5
1. 01. 5Par tial catch sh ares
0 2 4 6024681012
0. 00. 5
1. 0
1. 5Quo ta o nly
0 2 4 6024681012
0. 0
0. 51. 0
1. 5Effor t co ntrol
0 1 2 3 40510
15
0.00.51.0
1.5Cat ch share s
0 1 2 3 405
1015
0.00.5
1.01.5Pa rtial catch sh ares
0 1 2 3 405
1015
0.00.5
1.0
1.5Qu ota o nly
0 1 2 3 40
51015
0.0
0.51.0
1.5Effor t co ntrol
F/Ftarget ratiosn = 54
n = 24
n = 67
n = 27
▬ F
requ
ency
▬ Alaska, U.S.
▬ West coast, U.S.
▬ West coast, Canada
▬ NE & mid-Atl., U.S.
▬ Europe
▬ Australia
▬ New Zealand
▬ Other
▬ F
requ
ency
Probability density
Mean B/Btarget SD(target B/Btarget)
B/Btarget ratios
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Partial catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Quota only
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Effort control
0 1 2 30
5
10
15
20
0
1
2Catch shares
0 1 2 30
5
10
15
20
0
1
2Partial catch shares
0 1 2 30
5
10
15
20
0
1
2Quota only
0 1 2 30
5
10
15
20
0
1
2Effort control
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Partial catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Quota only
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Effort control
0 1 2 30
5
10
15
20
0
1
2Catch shares
0 1 2 30
5
10
15
20
0
1
2Partial catch shares
0 1 2 30
5
10
15
20
0
1
2Quota only
0 1 2 30
5
10
15
20
0
1
2Effort control
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Partial catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Quota only
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Effort control
0 1 2 30
5
10
15
20
0
1
2Catch shares
0 1 2 30
5
10
15
20
0
1
2Partial catch shares
0 1 2 30
5
10
15
20
0
1
2Quota only
0 1 2 30
5
10
15
20
0
1
2Effort control
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Partial catch shares
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Quota only
0 1 2 3 402468
1012
0.0
0.5
1.0
1.5Effort control
0 1 2 30
5
10
15
20
0
1
2Catch shares
0 1 2 30
5
10
15
20
0
1
2Partial catch shares
0 1 2 30
5
10
15
20
0
1
2Quota only
0 1 2 30
5
10
15
20
0
1
2Effort control
n = 67
n = 28
n = 82
n = 28
Catch share propensity scores
• Controls for non-random application of catch share “treatments”
• Logistic regression:
CS ~ Region + Habitat + avCatch + devYear + Lmax
• Use estimated coefficients to predict probability of each fishery
being under full catch shares during 2000–2004
• Use propensity scores as covariates in subsequent analyses
0 0.25 0.5 0.75 1
Canada-West coastAustralia
New ZealandSouth Africa
Canada-East coastSouth America
EuropeU.S.-Alaska
U.S.-NE/mid-Atl. U.S.-West coast
U.S.-S. Atl. /G. Mex
0 0.25 0.5 0.75 1
Benthopelagic fishInvertebrates
Benthic fishPelagic fish
Reef-associated fish
0 0.25 0.5 0.75 1
Catch sharesPartial catch shares
Quota onlyEffort control
Catch share propensity scores
Average propensity score
Region
Habitat
Catch control
0
0.2
0.4
0.6
0.8
1
0 5 10 15
Pro
pens
ity s
core
ln(average catch during 2000-2004)
Alaska
US W coast
Can W coast
Can E coast
US NE coast
US SE /GoMex
Europe
S. Africa
S. America
Australia
New Zealand
Propensity score matching
0
0.2
0.4
0.6
0.8
1
0 5 10 15
Pro
pens
ity s
core
ln(average catch during 2000-2004)
Can W coast
Australia
New Zealand
S Africa
Can E coast
S America
Europe
Alaska
US NE coast
US W coast
US SE /GoMex
● Actual full CS
X Actual non-CS
-1 -0.5 0 0.5
Propensity score matching
Mean C/QSD(target C/Q)
Minor (10%) overagesMajor (25%) overages
Mean F/Ftarget
SD(target F/Ftarget)Minor (10%) overfishingMajor (50%) overfishing
Mean B/Btarget
SD(target B/Btarget)Minor (10%) depletionMajor (50%) depletion
-1 0 1
Mean C/QSD(target C/Q)
P(C/Q > 1.1)P(C/Q > 1.25)
Mean F/FMSYSD(target F/FMSY)
P(F/FMSY > 1.1)P(F/FMSY > 1.5)
Mean B/BMSYSD(target B/BMSY)
P(B/BMSY > 1.1)P(B/BMSY > 1.5)
2.5th %ile 97.5th %ile
Grand mean of:
ResponseCS – ResponseNon-CS
Mean difference of response variable
0
0.2
0.4
0.6
0.8
1
1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2
0
0.2
0.4
0.6
0.8
1
1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2
0
0.2
0.4
0.6
0.8
1
0.10.20.30.40.50.60.70.80.91
Proportion of stocks in some undesirable state
Pro
babi
lity
of e
xcee
danc
e
C/Q
F/Ftarget
B/Btarget
(OK) (Bad)
Ŷ Catch shares
Ŷ Partial catch shares
Ŷ Quota only
Ŷ Effort regulations
0 50 100 150
Benthic fishBethopelagic fish
Pelagic fishReef-associated fish
Invertebrates
Number of stocks in analyses
0
30
Alaska, U.S.
0
30
Australia
0
30
60New
Zealand
0
30
East coast Canada
0
30
West coast Canada
0
30
Europe
0
30
SouthAfrica
0
30
South America
0
30
Northeast & mid-Atlantic coast, U.S.
0
30
S. Atlantic coast & Gulf
of Mexico, U.S.
0
30
West coast U.S.
0
0.2
0.4
0.6
0.8
1
1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2
Pro
babi
lity
of e
xcee
danc
e
'OK' 'Bad'F/Freference
-6 -4 -2 0-6 -4 -2 0-3 -2 -1 0-3 -2 -1 0
Catch sharesPartial catch shares
Quota only
Average catch
Development year
Lmax
Propensity score
Mean C/Q SD(target C/Q) Small overages (10%)
Large overages (25%)Mean C/Q SD(target C/Q)
Minor (10%) overages
Major (25%) overages
Fixed effect
coefficients(full model)
C/Q
Catch sharesPartial catch shares
Quota only
Average catchDevelopment year
Lmax
Propensity score
-3 -2 -1 0 1 2-3 -2 -1 0 1 2-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Alaska, U.S.West coast U.S.
West coast CanadaEast coast Canada
EuropeSouth Africa
AustraliaNew Zealand
Other
Benthic fishBenthopelagic fish
Pelagic fishReef-associated fish
Invertebrates
-3 -2 -1 0 1 2-3 -2 -1 0 1 2-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Alaska, U.S.West coast U.S.
West coast CanadaEast coast Canada
EuropeSouth Africa
AustraliaNew Zealand
Other
Benthic fishBenthopelagic fish
Pelagic fishReef-associated fish
Invertebrates
Random effect
conditional modes
* *
-3 -2 -1 0 1 2-3 -2 -1 0 1 2-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Alaska, U.S.West coast U.S.
West coast CanadaNE & mid-Atl., U.S.
EuropeNew Zealand
Other
Benthic fishBenthopelagic fish
Pelagic fishReef-associated fish
Invertebrates
-3 -2 -1 0 1 2-3 -2 -1 0 1 2-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Alaska, U.S.West coast U.S.
West coast CanadaNE & mid-Atl., U.S.
EuropeNew Zealand
Other
Benthic fishBenthopelagic fish
Pelagic fishReef-associated fish
Invertebrates
-3 -2 -1 0 1-3 -2 -1 0 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean F/F ref SD(target F/F ref)Minor overfishing
(10%)Major overfishing
(50%)F/Ftarget
Catch sharesPartial catch shares
Quota onlyEffort regulations
Average catchDevelopment year
Lmax
Propensity score
Mean F/Ftarget SD(target F/Ftarget)Minor (10%)
over-exploitationMajor (50%)
over-exploitation
Fixed effect
coefficients(full model)
Random effect
conditional modes
-5 -3 -1 1-5 -3 -1 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean F/F referenceSD(target F/F reference )
Minor overfishing (10%)
Major overfishing (50%)
-3 -2 -1 0 1-3 -2 -1 0 1-1.5 -1 -0.5 0 0.5-1.5 -1 -0.5 0 0.5
Catch sharesPartial catch shares
Quota onlyEffort control
Average catch
Development year
Lmax
Propensity score
Mean B/B ref SD(target B/B ref)Minor depletion
(10%)Major depletion
(50%)B/Btarget
Catch sharesPartial catch shares
Quota onlyEffort regulations
Average catchDevelopment year
Lmax
Propensity score
-3 -2 -1 0 1 2-3 -2 -1 0 1 2-1.5 -1 -0.5 0 0.5
Alaska, U.S.West coast U.S.
West coast CanadaEast coast CanadaNE & mid-Atl., U.S.
EuropeAustralia
New ZealandOther
Benthic fishBenthopelagic fish
Pelagic fishReef-associated fish
Invertebrates
-1.5 -1 -0.5 0 0.5 -3 -2 -1 0 1 2-3 -2 -1 0 1 2-1.5 -1 -0.5 0 0.5
Alaska, U.S.West coast U.S.
West coast CanadaEast coast CanadaNE & mid-Atl., U.S.
EuropeAustralia
New ZealandOther
Benthic fishBenthopelagic fish
Pelagic fishReef-associated fish
Invertebrates
-1.5 -1 -0.5 0 0.5
Mean B/Btarget SD(target B/Btarget)Minor (10%)
depletionMajor (50%)
depletion
Fixed effect
coefficients(full model)
Random effect
conditional modes
Filters applied
• Excluded oceanic sharks/tunas
• Excluded rarely targeted stocks
• Excluded stocks with catch shares or TACs established during 2000-2004
• Excluded stocks with missing time series data or reference points
• Excluded stocks whose assessments were not trustworthy (F, B only)
• Excluded stocks with >50% landings in recreational sector
• Excluded fisheries under moratorium 2000-2004 (C/Q, F only)
Sensitivity tests
• Removed propensity score covariate
• Excluded stocks whose Ftarget or Btarget reference points were estimated with Schaefer model
• Excluded ICES/NAFO-managed stocks
• Excluded stocks with C/Q < 0.5
• Excluded stocks under moratorium (biomass analyses)
• Considered only full catch share and quota-only categories
big reduction in sample
size
C/Q F/Ftarget B/Btarget
Catch shares 130 54 67
Partial catch shares 41 24 28
Quota only 88 67 82
Effort regulations ─ 27 28
Total 259 172 205
Number of stocks included in analyses after filtering
Mixed-effects model analysis
Y ~ (CControl + PS) + avCatch + devYear + Lmax + Region + Habitat
Y ~ (CControl + PS) + devYear + Lmax + Region + Habitat
Y ~ (CControl + PS) + avCatch + devYear + Region + Habitat
Y ~ (CControl + PS) + avCatch + Lmax + Region + Habitat
Y ~ (CControl + PS) + Region + Habitat
Y ~ Intercept + avCatch + devYear + Lmax + Region + Habitat
Y ~ Intercept + devYear + Lmax + Region + Habitat
Y ~ Intercept + avCatch + devYear + Region + Habitat
Y ~ Intercept + avCatch + Lmax + Region + Habitat
Y ~ Intercept + Region + Habitat
Catch control
included
Catch control
not included
Type of response variable :
Metric for each response variable :
Current catch to current quota
(C/Q)
Current exploitation rate to target
exploitation rate(F/Ftarget)
Current biomass to target biomass
(B/Btarget)
5-year meane.g. mean C/Q
Standard deviation around targete.g. SD(target C/Q)
Exceedance of minor undesirable thresholde.g. P(C/Q > 1.1)
Exceedance of major undesirable thresholde.g. P(C/Q > 1.25)
