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Aglen_Nakken_The effects of IUU fishing on stock assessments.pdf (182.0Kb)

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(1)

The effects of IUU fishing on stock assessments,

predictions and management advice

by

Asgeir Aglen and Odd Nakken

IMR Bergen, Norway

(2)

• Illegal

• Unregulated

• Unreported—assessment-prediction-advice

(3)

A g e Year 3 4 5 6 7 8 9 10 11 12 13+

2101 0 0 0 0 0 0 0 0 0 0 0

2102 0 0 0 0 0 0 0 0 0 0 0

2103 1 1 1 1 1 1 1 1 1 1 1

2104 1 2 2 2 2 2 2 2 2 2 2

2105 1 2 3 3 3 3 3 3 3 3 3

2106 1 2 3 4 4 4 4 4 4 4 4

2107 0 1 2 3 4 4 4 4 4 4 4

2108 0 0 1 2 3 4 4 4 4 4 4

2109 0 0 0 1 2 3 4 4 4 4 4

2110 0 0 0 0 1 2 3 4 4 4 4

2111 0 0 0 0 0 1 2 3 4 4 4

2112 0 0 0 0 0 0 1 2 3 4 4

2113 0 0 0 0 0 0 0 1 2 3 4

2114 0 0 0 0 0 0 0 0 1 2 4

2115 0 0 0 0 0 0 0 0 0 1 4

2116 0 0 0 0 0 0 0 0 0 0 4

2117 0 0 0 0 0 0 0 0 0 0 4

2118 0 0 0 0 0 0 0 0 0 0 4

(4)

A g e Catch SSB Year 3 4 5 6 7 8 9 10 11 12 13+ ‘000 T ‘000 T

2101 600 433 319 214 129 71 35.8 17.8 8.6 4.0 3.3 714 1337 2102 600 433 319 214 129 71 35.8 17.8 8.6 4.0 3.3 714 1337 2103 600 433 319 214 129 71 35.8 17.8 8.6 4.0 3.3 983 1337 2104 600 431 308 195 110 58 28.1 13.9 6.6 3.0 2.4 842 1098 2105 600 431 307 188 100 50 23.0 10.9 5.2 2.3 1.8 757 944 2106 600 431 307 187 97 45 19.8 8.9 4.1 1.8 1.4 710 853 2107 600 431 307 187 97 44 18.0 7.7 3.3 1.4 1.1 496 805 2108 600 433 317 206 113 53 22.1 8.9 3.7 1.6 1.1 560 937 2109 600 433 319 213 124 62 26.9 11.0 4.3 1.7 1.2 613 1062 2110 600 433 319 214 128 68 31.3 13.4 5.3 2.0 1.3 652 1163 2111 600 433 319 214 129 70 34.4 15.6 6.5 2.5 1.5 678 1236 2112 600 433 319 214 129 71 35.6 17.1 7.6 3.0 1.8 695 1282 2113 600 433 319 214 129 71 35.8 17.7 8.3 3.5 2.2 704 1310 2114 600 433 319 214 129 71 35.8 17.8 8.6 3.9 2.5 709 1324 2115 600 433 319 214 129 71 35.8 17.8 8.6 4.0 2.9 712 1331 2116 600 433 319 214 129 71 35.8 17.8 8.6 4.0 3.1 713 1334 2117 600 433 319 214 129 71 35.8 17.8 8.6 4.0 3.2 714 1337 2118 600 433 319 214 129 71 35.8 17.8 8.6 4.0 3.2 714 1337

Average 2103-2116 702 1144

(5)

Total stock biomass (tonnes)

0 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU78

Catch (tonnes)

0 200000 400000 600000 800000 1000000 1200000 1400000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU78

Spawning stock biomass (tonnes)

0 200000 400000 600000 800000 1000000 1200000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU78

Fishing mortality ages 5-10

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU78

Proportion reported

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

Const IUU78

Relative error: Estimated / True values

0 0.2 0.4 0.6 0.8 1 1.2 1.4

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

TSB SSB F

(6)

Total stock biomass (tonnes)

0 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU90

Catch (tonnes)

0 200000 400000 600000 800000 1000000 1200000 1400000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU90

Spawning stock biomass (tonnes)

0 200000 400000 600000 800000 1000000 1200000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU90

Fishing mortality ages 5-10

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Const IUU90

Proportion reported

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

Const IUU90

Relative error: Estimated / True values

0 0.2 0.4 0.6 0.8 1 1.2 1.4

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

TSB SSB F

(7)

Total stock biomass (tonnes)

0 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Dec IUU90

Catch (tonnes)

0 200000 400000 600000 800000 1000000 1200000 1400000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Dec IUU90

Spawning stock biomass (tonnes)

0 200000 400000 600000 800000 1000000 1200000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Dec IUU90

Fishing mortality ages 5-10

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Dec IUU90

Proportion reported

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

Dec IUU90

Relative error: Estimated / True values

0 0.2 0.4 0.6 0.8 1 1.2 1.4

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

TSB SSB F

(8)

Total stock biomass (tonnes)

0 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Inc IUU90

Catch (tonnes)

0 200000 400000 600000 800000 1000000 1200000 1400000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Inc IUU90

Spawning stock biomass (tonnes)

0 200000 400000 600000 800000 1000000 1200000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Inc IUU90

Fishing mortality ages 5-10

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Inc IUU90

Proportion reported

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

Inc IUU90

Relative error: Estimated / True values

0 0.2 0.4 0.6 0.8 1 1.2

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

TSB SSB F

(9)

Total stock biomass (tonnes)

0 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Var IUU

Catch (tonnes)

0 200000 400000 600000 800000 1000000 1200000 1400000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Var IUU

Spawning stock biomass (tonnes)

0 200000 400000 600000 800000 1000000 1200000

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

True catch Var IUU

Fishing mortality ages 5-10

0 0.2 0.4 0.6 0.8 1 1.2

1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003

True catch Var IUU

Proportion reported

0 0.2 0.4 0.6 0.8 1 1.2

1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003

Var IUU

Relative error: Estimated / True values

0 0.2 0.4 0.6 0.8 1 1.2 1.4

1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004

TSB SSB F

(10)

0 50000 100000 150000 200000 250000 300000 350000 400000

1990 1992 1994 1996 1998 2000 2002

(11)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

1990 1992 1994 1996 1998 2000 2002 2004

(12)

0 20000 40000 60000 80000 100000 120000 140000

1990 1992 1994 1996 1998 2000 2002 2004

(13)

0 0.2 0.4 0.6 0.8 1 1.2 1.4

1960 1970 1980 1990 2000 2010

(14)

0 50000 100000 150000 200000 250000 300000

1960 1970 1980 1990 2000 2010

(15)

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