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Longline CPUE standardization: IATTC 2006. Simon Hoyle and Mark Maunder. Introduction. Longline fisheries Indices of abundance Statistical methods Results & discussion Model selection Diagnostics CPUE indices Compare with last year Parameter estimates. Longline fisheries. Northern. - PowerPoint PPT Presentation
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Longline CPUE standardization: IATTC 2006
Simon Hoyle and Mark Maunder
Introduction
• Longline fisheries• Indices of abundance• Statistical methods• Results & discussion
– Model selection– Diagnostics– CPUE indices– Compare with last year– Parameter estimates
Longline fisheries
10
40
30
20
10
0
10
20
30
40
150 140 130 120 110 100 90 80 70
11
12
6
5
1, 13
2, 143, 15
4, 16 7
9
8
Baitboat Unassociated Longline
DolphinFloating Objects
Northern
Southern
Indices of abundance
• Standardized CPUE assumed proportional to abundance
• Japanese longline data, 1975 – 2004– Provided by SPC
• Catch in numbers, effort in hooks• Methods
– 2005 – delta gamma GLM– 2003-2004 – neural networks– 1999-2002 – regression trees
Statistical methods
• Strata defined as 5º square / HBF category– Only strata with at least 5 non-zero catches are
included• Delta lognormal model
• w = g(Year.qtr, Lat.Long, HBF, effort)• f(y) = h(Year.qtr, Lat.Long, HBF)
, 0,Pr( )
(1 ) ( ) otherwisew y
Y yw f y
Change from last year
• In 2005– Used delta gamma model– Didn’t include effort in delta component of
GLM• Delta lognormal fit the data better (AIC)• Change makes very little difference to
results
Catch and effort (northern)
Northern fishery
0
5
10
15
20
25
30
35
1975 1980 1985 1990 1995 2000 2005Year
Cat
ch (t
hous
ands
)
0
20
40
60
80
100
120
140
Effo
rt (th
ousa
nds
of h
ooks
)
Yellowfin catchBigeye catchEffort (hooks)
Catch and effort (southern)
Southern fishery
0
50
100
150
200
250
300
1975 1980 1985 1990 1995 2000 2005Year
Cat
ch (t
hous
ands
)
0
100
200
300
400
500
600
Effo
rt (th
ousa
nds
of h
ooks
)
YellowfinBigeyeEffort (hooks)
Un-standardized data – proportion zero & nonzero CPUE
Yellowfin northern
0
0.2
0.4
0.6
0.8
1
1975 1980 1985 1990 1995 2000 2005
Year
Prop
ortio
n no
n-ze
ro
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
Non-
zero
cat
ch p
er u
nit e
ffor
tProportion nonzero Nonzero CPUE
Yellowfin southern
0.75
0.8
0.85
0.9
0.95
1
1975 1980 1985 1990 1995 2000 2005
Year
Prop
ortio
n no
n-ze
ro
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Non
-zer
o ca
tch
per u
nit e
ffor
t
Proportion nonzero Non-zero CPUE
Bigeye northern
0
0.2
0.4
0.6
0.8
1
1975 1980 1985 1990 1995 2000 2005
Year
Prop
ortio
n no
n-ze
ro
0
0.5
1
1.5
2
2.5
3
Non
-zer
o ca
tch
per u
nit e
ffor
t
Proportion nonzero Nonzero CPUE
Bigeye southern
0.75
0.8
0.85
0.9
0.95
1
1975 1980 1985 1990 1995 2000 2005
Year
Prop
ortio
n no
n-ze
ro
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Non
-zer
o ca
tch
per u
nit e
ffor
t
Proportion nonzero Nonzero CPUE
Model selectionFishery Model Δ AICBET N yrqtr.latlong.hbf / lognormal 0
- hbf 118- latlong 6,080
BET S yrqtr.latlong.hbf / lognormal 0- hbf 817- latlong 13,575gamma 94,592
YFT N yrqtr.latlong.hbf / lognormal 0- hbf 30- latlong 1,237gamma 18,745
YFT S yrqtr.latlong.hbf / lognormal 0- hbf 336- latlong 32,936gamma 136,784
Residuals for non-zero component through time
1975 1980 1985 1990 1995 2000
-150
-100
-50
050
100
Northern bigeye
Time
Res
idua
ls
1975 1980 1985 1990 1995 2000 2005
-150
-100
-50
050
100
Northern yellowfin
Time
Res
idua
ls
1975 1980 1985 1990 1995 2000 2005
-200
-100
010
0
Southern bigeye
Time
Res
idua
ls
1975 1980 1985 1990 1995 2000 2005
-200
020
040
0
Southern yellowfin
Time
Res
idua
ls
Residuals for non-zero component
Southern bigeye
Residuals
Den
sity
-40 -20 0 20 40
0.00
0.02
0.04
0.06
0.08
Southern yellowfin
Residuals
Den
sity
-50 0 50
0.00
00.
005
0.01
00.
015
0.02
00.
025
0.03
0
Northern bigeye
Residuals
Den
sity
-40 -20 0 20 40
0.00
0.01
0.02
0.03
0.04
0.05
Northern yellowfin
Residuals
Den
sity
-60 -40 -20 0 20 40 60
0.00
0.01
0.02
0.03
Standardized CPUE - bigeye
Bigeye tuna
0
0.5
1
1.5
2
2.5
3
1975 1980 1985 1990 1995 2000 2005
Year
CP
UE
inde
x
Northern
Southern
Yellowfin tuna
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
1975 1980 1985 1990 1995 2000 2005
Year
CP
UE
inde
x
Northern
Southern
Standardized CPUE - yellowfin
Raw vs standardized CPUE
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1975 1980 1985 1990 1995 2000 20050
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
BET S raw
standardized
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
1975 1980 1985 1990 1995 2000 20050
0.5
1
1.5
2
2.5
3
3.5
YFT S raw
Standardized
Southern bigeye
y = -0.0051x + 11.126
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1975 1980 1985 1990 1995 2000 2005
Year
All f
acto
rs C
PUE
/ tim
e on
ly C
PUE
Standardized CPUE / CPUE standardized by time only
slope= -0.0051 ± 0.0006
Standardized CPUE / CPUE standardized by time only
Southern yellowfin
y = -0.0073x + 15.629
0
0.5
1
1.5
2
2.5
3
1975 1980 1985 1990 1995 2000 2005Year
All f
acto
rs C
PUE
/ tim
e on
ly C
PUE
slope = -0.007 ± 003
Average HBF through time
0
2
4
6
8
10
12
14
16
18
1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003
Year
Ave
rage
hoo
ks b
etw
een
float
s by
stra
tum
N
S
HBF parametersNorthern bigeye
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 2 4 6 8 10 12 14 16 18 20
Hooks between floats
Southern bigeye
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 2 4 6 8 10 12 14 16 18 20
Hooks between floats
Northern yellowfin
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 5 10 15 20 25
Hooks between floats
Southern yellowfin
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 5 10 15 20 25
Hooks between floats
Bigeye south12.5
7.5
2.5
-2.5
-7.5
-12.5
-17.5
-22.5
-27.5
-32.5
-37.5147.5 142.5 137.5 132.5 127.5 122.5 117.5 112.5 107.5 102.5 97.5 92.5 87.5 82.5 77.5 72.5
Lat
Long
2.25-2.5
2-2.25
1.75-2
1.5-1.75
1.25-1.5
1-1.25
0.75-1
0.5-0.75
0.25-0.5
0-0.25
Yellowfin south12.5
7.5
2.5
-2.5
-7.5
-12.5
-17.5
-22.5
-27.5
-32.5147.5 142.5 137.5 132.5 127.5 122.5 117.5 112.5 107.5 102.5 97.5 92.5 87.5 82.5 77.5 72.5
Lat
Long
3.5-4
3-3.5
2.5-3
2-2.5
1.5-2
1-1.5
0.5-1
0-0.5