purse seine (pp) purse seine (gam) · indian ocean bigeye tuna. example of application of pp and...
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Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 35
1975 1985 1995 2005 1975 1985 1995 2005
1975 1985 1995 2005 1975 1985 1995 2005
1975 1985 1995 2005 1975 1985 1995 2005
Purse seine (PP) Purse seine (GAM)
Longline (PP) Longline (GAM)
Total (PP) Total (GAM)
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
FIGURE 10Eastern Pacific bigeye tuna. Estimated trends in capacity utilization by gear type
and for all gears combined
Estimation of tuna fishing capacity from stock assessment-related information36
FIGURE 11Eastern Pacific bigeye tuna. Estimated trends of capacity output, excess capacity (EC) and
overcapacity (OC), with the PP and GAM methods. dOC: overcapacity estimated as the difference between capacity and “dynamic MSY” (dMSY)
1975 1980 1985 1990 1995 2000 2005
0
100
200
1975 1980 1985 1990 1995 2000 2005
0
100
1975 1980 1985 1990 1995 2000 2005
-100
0
100
Capacity
Excess capacity
Overcapacity
Thou
sand
s of
tonn
es
CatchPPGAMMSY
PPGAM
dMSY
OC (PP)OC (GAM)dOC (GAM)
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 37
FIGURE 12Eastern Pacific bigeye tuna. Relationship between estimated capacity output (Y axis) and fishing effort
(X axis), by fishery (number at the top of each panel)
0 2 4
0
1 000
2 000
1
0 1
0
10 000
2
0 1 2
0
10 000
20 000
3
0 1
0
1 000
4
0 1
0
4 000
8 000
5
0 2 4
0
10 000
6
0
0
2 000
4 000
7
0
8
0 300 600
10 000
20 000
9
0 1
0
400
800
10
0 1 2
0
1 000
11
0 1 2
0
200
40012
0 1
0
400
800
13
3 000
3 2
6 2 4 4 8 12
3
0
2 000
4 000
30 000
Tonn
es
Estimation of tuna fishing capacity from stock assessment-related information38
FIGURE 13Indian Ocean bigeye tuna. Example of application of PP and GAM methods to fishing mortality
of the purse-seine fishery
1950 1970 1990
0.00
0.05
0.10
0.15
0.20
PP
1950 1970 1990
GAM
0.00
0.05
0.10
0.15
0.20
The dark lines are the outputs from MULTIFAN-CL and the dashed line is the estimate of fishing capacity. Figure adapted from Arrizabalaga et al. (2009).
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 39
1950 1960 1970 1980 1990 2000 1950 1960 1970 1980 1990 2000
1950 1960 1970 1980 1990 2000 1950 1960 1970 1980 1990 2000
1950 1960 1970 1980 1990 2000 1950 1960 1970 1980 1990 2000
Purse seine (PP) Purse seine (GAM)
Longline (PP) Longline (GAM)
Total (PP) Total (GAM)
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
FIGURE 14Indian Ocean bigeye tuna. Estimated trends in capacity utilization by gear type and for
all gears combined
Estimation of tuna fishing capacity from stock assessment-related information40
FIGURE 15Indian Ocean bigeye tuna. Estimated trends of capacity output, excess capacity (EC) and overcapacity (OC),
with the PP and GAM methods
1950 1960 1970 1980 1990 2000
1950 1960 1970 1980 1990 2000
0
10
1950 1960 1970 1980 1990 2000
-100
0
20
0
10
Capacity
CatchPPGAMMSY
Excess capacity
Overcapacity
PPGAM
Thou
sand
s of
tonn
es
OC (PP)OC (GAM)
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 41
FIGURE 16Indian Ocean bigeye tuna. Relationship between estimated capacity output (Y axis) and fishing effort (X
axis) for the longline fishery
0 10 000 20 000 30 000
0
20 000
40 000
60 000
80 000
100 000
Tonn
es
Estimation of tuna fishing capacity from stock assessment-related information42
FIGURE 17Eastern Pacific yellowfin tuna. Example of application of PP and GAM methods to quarterly fishing
mortality of Fishery 10 (pole and line in Regions 1-13)
1975 1980 1985 1990 1995 2000 2005
0.0000
0.0010
1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
0.0000
0.0010
0.0000
0.0010
0.0000
0.0010
0.0000
0.0010
0.0000
0.0010
0.0000
0.0010
0.0000
0.0010
PP quarter 1 GAM quarter 1
PP quarter 2 GAM quarter 2
PP quarter 3 GAM quarter 3
PP quarter 4 GAM quarter 4
0.0020 0.0020
0.0020 0.0020
0.0020 0.0020
The dark lines are the outputs from MULTIFAN-CL and the dashed line is the estimate of fishing capacity.
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 43
FIGURE 18Eastern Pacific yellowfin tuna. Estimated trends in capacity utilization by gear type and
for all gears combined
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
0.0
0.4
0.8
Purse seine (PP) Purse seine (GAM)
Longline (PP) Longline (GAM)
Other gears (GAM)
Total (PP) Total (GAM)
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
Other gears (PP)
Estimation of tuna fishing capacity from stock assessment-related information44
FIGURE 19Eastern Pacific yellowfin tuna. Estimated trends of capacity output, excess capacity (EC) and
overcapacity (OC), with the PP and GAM methods. dOC: overcapacity estimated as the difference between capacity and “dynamic MSY” (dMSY)
1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005
0
100
200
1975 1980 1985 1990 1995 2000 2005
0
200
400
-100
0
200
400
600 CatchPPGAMMSY
PPGAM
dMSY
OC (PP)OC (GAM)dOC (GAM)
Capacity
Excess capacity
Overcapacity
Thou
sand
s of
tonn
es
Figure adapted from Arrizabalaga et al. (2009).
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 45
FIGURE 20Eastern Pacific yellowfin tuna. Relationship between estimated capacity output (Y axis) and
fishing effort (X axis), by fishery (number at the top of each panel)
0 10
4 000
1
0 1 20
4 000
2
0
10 000
3
0
4
0 2 40
10 000
5
0
0
20 000
6
0
7
0
8
0 4 8 12 0
10 000
9
0 2 4 0
1 0002 000
10
0 10 20 0
1 000
11
0 100 200 0
10 000
12
0 10
200
40013
0 1 20
1 000
14
0 4 20
400
800
15
0 1 2
16
3 0 2 4 0 1 2 3
8 00012 000 8 000 20 000
4 000
8 000
2 4 2 1 2
20 000
30 000 40 000
0
20 000
40 000
020 000
40 00060 000
20 000
30 0003 000
30 300
3
1 200
30
400
800
Tonn
es
Estimation of tuna fishing capacity from stock assessment-related information46
1960 1970 1980 1990 2000
0.000
0.004
1960 1970 1980 1990 2000
1960 1970 1980 1990 2000
0.00
0.02
1960 1970 1980 1990 2000
1950 1960 1970 1980 1990 2000
0.000
1950 1960 1970 1980 1990 2000
1950 1960 1970 1980 1990 2000 1950 1960 1970 1980 1990 2000
PP quarter 1 GAM quarter 1
PP quarter 2 GAM quarter 2
PP quarter 3 GAM quarter 3
PP quarter 4 GAM quarter 4
0.000
0.004
0.00
0.02
0.000
0.010
0.020
0.000 0.000
0.010
0.010
0.020
0.010
0.04 0.04
0.008 0.008
0.012 0.012
FIGURE 21Western and Central Pacific yellowfin tuna. Example of application of PP and GAM methods to quarterly
fishing mortality of Fishery 10 (all longline except that of Australia in Region 5)
The dark lines are the outputs from MULTIFAN-CL and the dashed line is the estimate of fishing capacity.
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 47
FIGURE 22Western and Central Pacific yellowfin tuna. Estimated trends in capacity utilization by gear type and
for all gears combined
1950 1960 1970 1980 1990 2000 1950 1960 1970 1980 1990 2000
1970 1980 1990 2000 1970 1980 1990 2000
1970 1980 1990 2000 1970 1980 1990 2000
1950 1960 1970 1980 1990 2000 1950 1960 1970 1980 1990 2000
Purse seine (PP) Purse seine (GAM)
Longline (PP) Longline (GAM)
Other gears (GAM)
Total (PP) Total (GAM)
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
Other gears (PP)
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
Estimation of tuna fishing capacity from stock assessment-related information48
FIGURE 23Western and Central Pacific yellowfin tuna. Estimated trends of capacity output, excess capacity (EC) and
overcapacity (OC), with the PP and GAM methods. dOC: overcapacity estimated as the difference between capacity and “dynamic MSY” (dMSY)
1950 1960 1970 1980 1990 2000
1950 1960 1970 1980 1990 2000
0
100
1950 1960 1970 1980 1990 2000
0
40
0
-20
-60
200
Capacity
Excess capacity
Overcapacity
PPGAM
Thou
sand
s of
tonn
es
CatchPPGAMMSYdMSY
OC (PP)OC (GAM)dOC (GAM)
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 49
FIGURE 24Western and Central Pacific yellowfin tuna. Relationship between estimated capacity output (Y axis)
and fishing effort (X axis), by fishery (number at the top of each panel)
0 2000 40000
1 000
1
0 2000
400
800
2
0 20 400
100
200
3
0 200 600
10 000
20 0004
0 400 800
2 000
6 000
5
0 4 12
0
200
400
6
0 1000
0
10 000
7
0 40 80
0
1 000
8
0 20 400
200400
9
0 400 8000
2 000
10
0 10 200
1 000
11
0 400 8000
2 000
12
0 100 200 0
1 000
2 000
13
0 10 200
10 000
14
0 10
0
20 000
15
0 100
10 000
16
0 4 8
0
20 000
17
0 4 8
10 000
20 000
18
0 100 200
4 000
12 000
19
6000 400 60 400
2 000
8
10 000
60 30
6004 000
6 000
20 000 40 000
300
40 000
60 00030 000
8 000
16 000
Tonn
es
Figure adapted from Arrizabalaga et al. (2009).
Estimation of tuna fishing capacity from stock assessment-related information50
FIGURE 25Western and Central Pacific skipjack tuna. Example of application of PP and GAM methods to quarterly
fishing mortality of Fishery 10 (Japanese distant-water pole-and-line fishery in Region 5)
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005
0.000
0.010
1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 1975 1980 1985 1990 1995
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
PP quarter 1 GAM quarter 1
PP quarter 2 GAM quarter 2
PP quarter 3 GAM quarter 3
PP quarter 4 GAM quarter 4
0.00
0.02
0.00
0.02
0.000
0.010
0.000
0.010
0.000
0.010
0.000
0.010
0.000
0.010
0.020 0.020
The dark lines are the outputs from MULTIFAN-CL and the dashed line is the estimate of fishing capacity.
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 51
FIGURE 26Western and Central Pacific skipjack tuna. Estimated trends in capacity utilization by gear type and
for all gears combined
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005
Purse seine (PP) Purse seine (GAM)
Longline (PP) Longline (GAM)
Other gears (GAM)
Total (PP) Total (GAM)
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
Other gears (PP)
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
0.0
0.4
0.8
Estimation of tuna fishing capacity from stock assessment-related information52
FIGURE 27Western and Central Pacific skipjack tuna. Estimated trends of capacity output, excess capacity (EC) and
overcapacity (OC), with the PP and GAM methods
1975 1980 1985 1990 1995 2000 2005
1975 1980 1985 1990 1995 2000 2005
0
400
1975 1980 1985 1990 1995 2000 2005
0
-1 000
0
1 000
800
1 200
2 000
CatchPPGAMMSY
PPGAM
OC (PP)OC (GAM)
Capacity
Excess capacity
Overcapacity
Thou
sand
s of
tonn
es
Sensitivity tests and application to Pacific, Atlantic and Indian Ocean tuna stocks 53
FIGURE 28Western and Central Pacific skipjack tuna. Relationship between estimated capacity output (Y axis)
and fishing effort (X axis), by fishery (number at the top of each panel)
0 100 3000
10 000
1
0 500 1500
0
400
8002
0 10000
30 000
3
0 300 600
0
10 000
4
0 2 40
30 000
5
0 100 2000
10 000
6
0 1000
15 000
7
0 200
0
15 000
8
0 400
0
30 000
10
0 1 20
10 000
11
0 10 200
10 000
12
0 40 800
100 000
13
0 100
0
20 000
14
0 1 2
0
100 000
15
0 2000
20 000
19
0 400 800
0
1 000
20
0 2 4
0
20 000
21
0 20
0
40 000
22
0 4 80
100 000
23
3006
60 000
3
2 000
3 00040 00040 000
200
40 000
60 000 80 000
Tonn
es
1616FAO FISHERIES AND AQUACULTURE PROCEEDINGS
ISSN 2070-6103
14–16 May 2007La Jolla, California, United States of America
FAOFISHERIES ANDAQUACULTUREPROCEEDINGS
Estimation of tuna fishing capacity from stock assessment-related informationWorkshop to Further Develop, Test and Apply a Method for the Estimation of Tuna Fishing Capacity from Stock Assessment-Related Information
Estimation of tuna fishing capacity from stock assessment-related informationWorkshop to Further Develop, Test and Apply a Method for the Estimation of Tuna Fishing Capacity from Stock Assessment-Related Information
14–16 May 2007
La Jolla, California, United States of America
These Proceedings include (i) the Report of and (ii) the paper
presented at the Workshop to Further Develop, Test and Apply
a Method for the Estimation of Tuna Fishing Capacity from Stock
Assessment-Related Information. The Workshop was hosted by
the Inter-American Tropical Tuna Commission (IATTC) in La Jolla,
California, United States of America, from 14 to16 May 2007. It
was organized by the Japan-funded Project on the “Management
of Tuna Fishing Capacity: Conservation and Socio-Economics” of
the Food and Agriculture Organization of the United Nations (FAO)
in collaboration with and with in-kind support of several
international and national fisheries institutions involved in tuna
fisheries research and management. The Report outlines the
discussions carried out at the Workshop, some proposals
for further work, recommendations and conclusions of
the Workshop.
9 7 8 9 2 5 1 0 6 4 3 4 4
I1212E/1/10.09/860
ISBN 978-92-5-106434-4 ISSN 2070-6103