Download Preliminarily analysis for target species of Japanese longline fishery

ISC/13/ALBWG/13
Preliminarily analysis for target species of Japanese longline
fishery operated in the North Pacific Ocean
Keisuke Satoh, Hirotaka Ijima, Hidetada Kiyofuji and Hiroaki Okamoto
National Research Institute of Far Sea Seas Fisheries
Fisheries Research Agency
5-7-1 Orido, Shimizu-ku, Shizuoka-shi
424-8633 Japan
Email: [email protected]
1
This working paper was submitted to the ISC Albacore Working Group Intercessional
Workshop, 19-26 March 2013, held at the College of Marine Sciences, Shanghai Ocean
University, Shanghai, China. Document not to be cited without author’s permission.
Preliminarily analysis for target species of Japanese longline fishery operated in the North
Pacific Ocean
Keisuke Satoh1, Hirotaka Ijima1, Hidetada Kiyofuji1 and Hiroaki Okamoto1
1 National Research Institute of Far Seas Fisheries, 5-7-1 Shimizu-ku, Shizuoka 424-8633, Japan.
SUMMALY
In order to understand the target species of Japanese longline fishery in the Pacific Ocean from 1993 to 2002,
we investigated historical changes of (1) species composition (albacore, bigeye and yellowfin) of the fishery,
(2) distribution of number of fish per set using operational logbook data and (3) market price in Japanese
fishing ports, and amount of import. Four pieces of evidence revealed the operation of targeting albacore of
Japanese longline fishery in the North Pacific Ocean increased in this period from 1993 to 2002. First, the
historical trend for species composition represented the proportion for albacore was high and the proportion for
bigeye was low in this period. Second, elongation of fishing season for albacore of the large vessel occurred
for the large vessel, which had been often observed before 1970 when the fishery mainly targeted albacore.
Third, the proportion of zero catch and more than 100 fish per set for albacore of the large vessel was lower
and very high, respectively. Such high proportion was also observed before 1970. The last one, the total
quantity demanded for albacore and bigeye increased and decreased, respectively.
1. INTRODUCTION
Standardized CPUE for albacore caught by Japanese longline fishery in the North Pacific Ocean increased and
decreased in 1990s (from 1992 to 2002), and the stock assessment model cannot explain this trend. Therefore
further exploration of Japanese longline CPUE was recommended in the last stock assessment (Anonymous
ISC 2011). To address the point, we focus on historical changes of target species of the fishery. If albacore had
been targeted in 1990s by Japanese longline, nominal CPUE could be high and then the standardized CPUE
might be biased without consideration for targeting effect.
Japanese fishermen of longline with large vessel (larger than 20 gross register tonnages (GRT)) had
generally targeted albacore until early 1970s, and then they changed their target species as bigeye in tandem
with the penetration of deep setting and nylon for material of main and branch line. After that the main target
species was not seen as not having largely changed. However consistent increasing of albacore catch by
Japanese longline fishery since 1990 in the Indian Ocean (Matsumoto 2012) and increasing trend with some
fluctuation since 1995 in the Atlantic Ocean (Anonymous ICCAT 2012a) indicate changing of target species of
the fishery after 1990s.
2
For small vessel (10-19 GRT), it is difficult to descript historical target species before 1993 due to
lack of logbook. However we try to review typical fishing schedule and target species. Application of deep
setting and nylon for line material seems to have smaller impact on changing target species rather than large
vessel. The small vessels have changed target species seasonally and opportunistically as albacore, yellowfin,
bigeye and bluefin. They target albacore in 1st quarter and then move to bluefin, and stop fishing from June to
August. They resume fishing in September to catch bigeye in eastern area of the North Pacific Ocean (35 to 40
N, from coast line of Japan to 160 E). The fishing season for bigeye continue to December or early January.
They also catch yellowfin in coastal area from late spring to summer. There should be many exemptions for
the typical schedule. For example, some vessels go to tropical area year-round and catch tropical tuna, and
smaller sized vessels tend to operate in coastal area and target albacore, and some vessels catch albacore in
southern part of the eastern area in 4th quarter in recent years.
In order to understand the target species of Japanese longline fishery in the Pacific Ocean from 1993
to 2002, we investigated historical changes of (1) species composition (albacore, bigeye and yellowfin) of the
fishery, (2) distribution of number of fish per set using operational logbook data and (3) market price in
Japanese fishing ports, and amount of import.
2. MATERIALS AND METHODS
In this paper, two kinds of data were mainly used. One is the Annual Report of Catch Statistic on Fishery and
Aquaculture published by the Statistics and Information Department, Ministry of Agriculture, Forestry and
Fisheries (SID report). This report provides comprehensive statistic for Japanese fisheries including catch,
number of vessel, and market price by species. The amount of catch by species from 1970 and the market
prices from 1977 were used. The market price is based on information from large number of fishing port (155
ports in 2011). The other is logbook database which has been compiled at National Research Institute of Far
Seas Fisheries (NRIFSF) based on the logbook mandatory submitted by fishermen. The databases for LL
vessels larger than 20 GRT (large vessel) and for LL of 10-19 GRT (small vessel) are available for 1952-2011
and 1994-2011, respectively. The coverage rates of logbooks for large and small vessel were near 100% and
about 70%, respectively (Matsumoto et al. 2013). In this document, the catch in number and effort was not
raised for small vessel. For the species composition analysis the Japanese longline catch and effort statistics
from 1952 up to 2011 were used. The amounts of catch by species (albacore yellowfin and bigeye) in this
document are estimated by same procedure documented in Satoh et al (2012) using SID report and logbook
database. We used trade statistics of Japan Ministry of Finance for amount of import of frozen albacore,
yellowfin and bigeye from 1988 (http://www.customs.go.jp/toukei/info/). All statistics except for trade
statistics for 2011 and 2012 in this report were preliminary.
3. RESULTS AND DISCUSSIONS
3
3.1. Species composition
The number of large longline vessel and the number of hooks had decreased consistently since 1994 (Fig. 1).
On the other hand, the number of small vessel and the number of hooks had slightly increased since 1994. The
fishing ground for the large vessel distribute all over the world including the North Pacific Ocean, small
vessels operate in the vicinity of Japan (Appendices 1, 2). The proportion of effort for the large vessel by sea
area (the Atlantic Ocean, the Indian Ocean, North Pacific Ocean (10-40N) and other part of the Pacific Ocean)
indicated that the proportion for the North Pacific Ocean did not change from 1993 to 2002 (Fig. 2) and
shifting of effort from other area to the north Pacific was not clear. Therefore we should focus on the North
Pacific Ocean.
The amount of albacore was higher from 1993 to 2002 for the both vessel type (Fig. 3). The amount of
bigeye and yellowfin decreased in the same period for the both vessel type. The historical trend for species
composition for the both vessel type represented complementary relationship between albacore and bigeye
(Fig. 4). In this period with higher albacore CPUE, the proportion for albacore was high and the proportion for
bigeye was low.
In this period (from 1993 to 2002) the relatively large catch of albacore for the large vessel was
detected in 2nd and 3rd quarter, whereas catches for bigeye and yellowfin in the same season did not occur (Fig.
5). Such elongation of fishing season for albacore often occurred before 1970 when the fishery mainly targeted
albacore. For the small vessel, there was no large difference between the period from 1993 to 2002 and after
2003(Fig. 6), partially because the catch of albacore for the small vessel remained much higher since 1994
(Fig. 3).
3.2. Number of fish per set
The proportion of zero catch (zero fish per set) for albacore of large vessel from 1993 to 2002 was lower than
other years especially in 2nd and 3rd quarter (Fig. 7). The proportion of medium catch, more than one fish to
less than 20 fish per set, did not change between the period (1993 to 2002) and other years. The proportion for
large catch, more than 20 fish to less than 100 fish per set, increased in this period in all four quarters. The
proportion for more than 100 fish per set in this period drastically increased in main fishing season (1st and 4th
quarter). Such high proportion was also observed before 1970. For bigeye and yellowfin in this period (Figs. 8,
9), the proportions of zero catch per set increased and the proportion of medium catch (>=1 and <20 fish per
set) decreased. Same analysis was applied for the small vessel (Figs. 10-12), the proportion for more than 100
fish per set from 1994 to 2002 in 1st quarter was larger than after 2003, and the zero catch for yellowfin
increased and the proportion for medium catch (>=1 and <20 fish per set) decreased.
3.3. Market price and amount of import
Market prices (yen kg-1) for fresh and frozen albacore in this period from 1993 to 2002 showed stable, for fresh
albacore was from 331 yen kg-1 in 1993 to 278 yen kg-1 in 2002 (Fig. 13). The prices for fresh bigeye was
1,609 (yen kg-1) in 1993 and then decreased to 1,006 (yen kg-1) in 2002, which is about 40% discount. The
products of the market price and amount of catch are total value of albacore and bigeye, which is roughly
4
considered as total quantity demanded for these species. The main usages for albacore and bigeye are for
canning and sashimi, respectively, thus it is questionable that albacore can replace bigeye straightforward.
However in this period the total quantity demanded for albacore and bigeye increased and decreased,
respectively (Fig. 14). Japan had experienced long business depression in this period, therefore Japanese
consumer may tend to select more reasonable tuna under the tight economic times. Total catch for these tuna
species by Japanese fishery, including longline, purse seine, pole and-line, etc, revealed decreasing of amounts
of catch for bigeye and yellowfin. Total amount of import for frozen yellowfin showed downward trend from
1994 to 1999. In addition, unfortunately we cannot detect statistics of import for bigeye in this period (Fig. 15).
Therefore the decreasing of demand for bigeye could be derived from shortage in supply for bigeye, and the
shortage was not adequately filled with yellowfin, thus albacore should partially compensate the deficiency of
bigeye in this period.
The directivity for albacore could be induced by shortage of supply of bigeye around 1992, where
stock status of bigeye had become worse in many areas (Appendices 3-6, WCPO; Davies et al (2011), EPO;
Aires-da-Silva and Maunder (2012b), IDO; Nishida and Rademeyer (2011), ATL; Anonymous (ICCAT
2012b)). The first choice for the replacement may be yellowfin, however amount of catch for yellowfin of
Japanese fishery and amount of import did not increase in this period. Their stock status in early 1990 had
become worse or was stable (Appendices 7-10, WCPO; Langley et al (2011), EPO; Aires-da-Silva and
Maunder (2012a), IDO; Langley et al (2012), ATL; Anonymous (ICCAT 2011a)). Just at that time stock size
of the North Pacific albacore had start to increase, which leaded to high availability of albacore. The good
catch of albacore did not result in falling down of their market price due to weak supply of bigeye and
yellowfin. The stable market price of albacore is sufficient reason for Japanese fishermen to continue to target
albacore.
In summary, four pieces of evidence revealed the operation of targeting albacore of Japanese longline fishery
in the North Pacific Ocean increased in this period from 1993 to 2002. First, the historical trend for species
composition represented the proportion for albacore was high and the proportion for bigeye was low in this
period. Second, elongation of fishing season for albacore of the large vessel occurred for the large vessel,
which had been often observed before 1970 when the fishery mainly targeted albacore. Third, the proportion of
zero catch and more than 100 fish per set for albacore of the large vessel was lower and very high, respectively.
Such high proportion was also observed before 1970. The last one, the total quantity demanded for albacore
and bigeye increased and decreased, respectively.
4. REFERENCES
Anonymous (ICCAT). 2011a. Report of the 2011 ICCAT yellowfin tuna stock assessment session 113pp.
Anonymous (ICCAT). 2012a. Annual report of Japan. ANN-022/2012. 17pp.
Anonymous (ICCAT). 2012b. Report of the standing committee on research and statistics (SCRS). PLE-104 /
5
2012
Anonymous (ISC). 2011. Stock assessment of albacore tuna in the North Pacific Ocean in 2011. Report of the
albacore working group stock assessment workshop. International Scientific Committee for Tuna and
Tuna-like Species in the North Pacific Ocean. 4-11 June 2011 Shizuoka, Japan. 143pp.
Aires-da-Silva, A. and Maunder M.N. 2012a. Status of yellowfin tuna in the eastern Pacific Ocean in 2011 and
outlook for the future. SAC-03-05. 12pp.
Aires-da-Silva, A. and Maunder M.N. 2012b. Status of bigeye tuna in the eastern Pacific Ocean in 2011 and
outlook for the future. SAC-03-06. 12pp.
Davies, N., Hoyle, S., Harley S., Langley, A., Kleiber, P. and Hampton, J. 2011. Stock assessment of bigeye
tuna in the western and central Pacific Ocean. WCPFC-SC7-2011/SA-WP-02. 133pp.
Langley, A., Hoyle, S. and Hampton, J. 2011. Stock assessment of yellowfin tuna in the western and central
Pacific Ocean. WCPFC-SC7-2011/SA-WP-03. 135pp.
Langley, A., Herrera, M. and Million, J. 2012. Stock assessment of yellowfin tuna in the Indian Ocean using
MULTIFAN-CL. IOTC–2012–WPTT14–38 Rev_1. 72pp.
Matsumoto, T. 2012. Review of Japanese longline fishery and its albacore catch in the Indian Ocean.
IOTC/2012/WPTmT04/09. 23pp.
Matsumoto, T., Kiyofuji, H. and Okamoto, H. 2013. Suggestion of alternative estimation of albacore catch by
Japanese coastal longline fishery to apply to stock synthesis model. ISC/13/ALBWG/12. 12pp.
Nishida, T. and Rademeyer, R. 2011. Stock and risk assessments on bigeye tuna (Thunnus obesus) in the
Indian Ocean based on AD Model Builder implemented Age-Structured Production Model (ASPM).
IOTC-WPTT13-2010-42 (rev. 2). 23pp.
Satoh, K., Uosaki, K., Matsumoto, T. and Okamoto, H. 2012. A review of Japanese albacore fisheries in the
North Pacific as of June 2012. ISC/12/ALBWG-3/02. 15pp.
6
small vessel (10‐19 GRT)
large vessel (>=20 GRT)
Number of vessels
500
400
300
200
100
0
1995
2000
2005
small vessel (10‐19 GRT)
2010
large vessel (>=20 GRT)
Number of hooks (x 1000)
200,000
150,000
100,000
50,000
0
1981
1985
1990
1995
2000
2005
2010
Fig. 1 Historical changes of number of active vessel (upper) and number of hooks (lower) by vessel size of
1.0
the Atlantic Ocean
the Indian Ocean
0.8
other area of the Pacific Ocean
northwestern Pacific Ocean (10‐40N)
0.6
0.4
0.2
0.0
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
proportion of effort (number of hooks)
Japanese longline in the North Pacific Ocean. The period with higher CPUE represent blue shaded area.
Fig. 2 Historical changes of proportion of effort (number of hooks) by Ocean and area. The period with
higher CPUE represent blue shaded area.
7
North Pacific (large vessel)
catch by species
70000
ALB
BET
YFT
60000
50000
40000
30000
20000
10000
0
1970
1975
1980
1985
1990
1995
2000
2005
2010
2000
2005
2010
North Pacific (small vessel)
catch by species
30000
ALB
BET
YFT
25000
20000
15000
10000
5000
0
1970
1975
1980
1985
1990
1995
Fig. 3 Amount of catch (ton) by species of Japanese longline operated in the North Pacific Ocean. Upper
panel for large vessel (distant water + offshore water, >=20GRT), lower panel for small vessel (coastal water,
10-19 GRT). The period with higher CPUE represent blue shaded area.
proportion of catch by species
large vessel
0.8
ALB
BET
YFT
0.6
0.4
0.2
0.0
1970
1975
1980
1985
1990
1995
2000
2005
2010
1995
2000
2005
2010
proportion of catch by species
small vessel
0.8
ALB
BET
YFT
0.6
0.4
0.2
0.0
1970
1975
1980
1985
1990
Fig. 4 Proportion of amount of catch by species of Japanese longline operated in the North Pacific Ocean.
Upper panel for large vessel (distant water + offshore water; >=20GRT), lower panel for small vessel (coastal
water, 10-19 GRT). The period with higher CPUE represent blue shaded area.
8
(A)
large vessel, effort
No. of hooks (x 1000)
60000
Q1
Q2
Q3
Q4
40000
20000
(B)
2009
2006
2003
2000
1997
1994
1991
1988
1985
1982
1979
1976
1973
1970
1967
1964
large vessel, albacore
800
No. of fish (x 1000)
1961
1958
1955
1952
0
Q1
Q2
Q3
Q4
600
400
200
(C)
2009
2006
2003
2000
1997
1994
1991
1988
1985
1982
1979
1976
1973
1970
1967
1964
large vessel, bigeye
400
No. of fish (x 1000)
1961
1958
1955
1952
0
Q1
Q2
Q3
Q4
200
1988
1991
1994
1997
2000
2003
2006
2009
1991
1994
1997
2000
2003
2006
2009
1985
1982
1979
1976
1973
1970
1967
1964
1961
large vessel, yellowfin
200
No. of fish (x 1000)
1988
(D)
1958
1955
1952
0
Q1
Q2
Q3
Q4
100
1985
1982
1979
1976
1973
1970
1967
1964
1961
1958
1955
1952
0
Fig. 5 Historical changes of effort (A; number of hooks (x1000)), (B) albacore, (C) bigeye and (D) yellowfin
by quarter caught by Japanese large longline vessel in the North Pacific Ocean (10-40N). The period with
higher CPUE represent blue shaded area.
9
(A)
small vessel, effort
Q1
Q2
Q3
Q4
No. of hooks (x 1000)
30000
20000
10000
(B)
small vessel, albacore
Q1
Q2
Q3
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
0
Q4
No. of fish (x 1000)
800
600
400
200
(C)
small vessel, bigeye
Q1
Q2
Q3
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
0
Q4
No. of fish (x 1000)
100
80
60
40
20
(D)
small vessel, yellowfin
Q1
Q2
Q3
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
0
Q4
No. of fish (x 1000)
80
60
40
20
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
0
Fig. 6 Historical changes of effort (A; number of hooks (x1000)), (B) albacore, (C) bigeye and (D) yellowfin
by quarter caught by Japanese small longline vessel in the North Pacific Ocean (10-40N). The period with
higher CPUE represent blue shaded area.
10
large vessel, albacore, zero per set
(A)
1.0
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
(B)
large vessel, albacore, >=1 and < 20 fish per set
1.0
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
(C)
large vessel, albacore, >=20 and < 100 fish per set
0.6
proportion
Qt1
Qt2
Qt3
Qt4
0.4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
(D)
large vessel, albacore, >=100 fish per set
0.2
proportion
Qt1
Qt2
Qt3
Qt4
0.1
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
Fig. 7 Proportion of catch number per set of albacore by quarter caught by Japanese large longline vessel in
the North Pacific Ocean. (A) case for zero catch per set, (B) case for 1-19 fish per set, (C) case for 20-99
fish per set, (D) case for more than 100 fish per set. The period with higher CPUE represent blue shaded
area. For each quarter the sum of proportion from four panels is 1.
11
large vessel, bigeye, zero per set
(A)
0.8
Qt1
Qt2
Qt3
Qt4
proportion
0.6
0.4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
(B)
large vessel, bigeye, >=1 and < 20 fish per set
1.0
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
(C)
large vessel, bigeye, >=20 fish per set
0.4
proportion
Qt1
Qt2
Qt3
Qt4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
Fig. 8 Proportion of catch number per set of bigeye by quarter caught by Japanese large longline vessel in the
North Pacific Ocean. (A) case for zero catch per set, (B) case for 1-19 fish per set, (C) case for more than 20
fish per set. The period with higher CPUE represent blue shaded area. For each quarter the sum of
proportion from three panels is 1.
12
large vessel, yellowfin, zero per set
(A)
1.0
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
(B)
large vessel, yellowfin, >=1 and < 20 fish per set
1.0
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
(C)
large vessel, yellowfin, >=20 fish per set
0.4
proportion
Qt1
Qt2
Qt3
Qt4
0.2
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
0.0
Fig. 9 Proportion of catch number per set of yellowfin by quarter caught by Japanese large longline vessel in
the North Pacific Ocean. (A) case for zero catch per set, (B) case for 1-19 fish per set, (C) case for more than
20 fish per set. The period with higher CPUE represent blue shaded area. For each quarter the sum of
proportion from three panels is 1.
13
(A)
1.0
small vessel, albacore, zero per set
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
(B)
1.0
small vessel, albacore, >=1 and < 20 fish per set
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
(C)
1.0
small vessel, albacore, >=20 and < 100 fish per set
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
(D)
proportion
0.4
small vessel, albacore, >=100 fish per set
Qt1
Qt2
Qt3
Qt4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fig. 10 Proportion of catch number per set of albacore by quarter caught by Japanese small longline vessel
in the North Pacific Ocean. (A) case for zero catch per set, (B) case for 1-19 fish per set, (C) case for 20-99
fish per set, C) case for more than 100 fish per set. The period with higher CPUE represent blue shaded area.
For each quarter the sum of proportion from four panels is 1.
14
(A)
small vessel, bigeye, zero per set
Qt1
1.0
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
(B)
small vessel, bigeye, >=1 and < 20 fish per set
1.0
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
(C)
small vessel, bigeye, >=20 fish per set
0.2
Qt2
Qt3
Qt4
proportion
Qt1
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fig. 11 Proportion of catch number per set of bigeye by quarter caught by Japanese small longline vessel in
the North Pacific Ocean. (A) case for zero catch per set, (B) case for 1-19 fish per set, (C) case for more than
20 fish per set. The period with higher CPUE represent blue shaded area. For each quarter the sum of
proportion from three panels is 1.
15
(A)
small vessel, yellowfin, zero per set
Qt1
1.0
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
(B)
small vessel, yellowfin, >=1 and < 20 fish per set
1.0
Qt1
Qt2
Qt3
Qt4
proportion
0.8
0.6
0.4
0.2
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
(C)
small vessel, yellowfin, >=20 fish per set
0.2
Qt2
Qt3
Qt4
proportion
Qt1
0.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Fig. 12 Proportion of catch number per set of yellowfin by quarter caught by Japanese small longline vessel
in the North Pacific Ocean. (A) case for zero catch per set, (B) case for 1-19 fish per set, (C) case for more
than 20 fish per set. The period with higher CPUE represent blue shaded area. For each quarter the sum of
proportion from three panels is 1.
16
0
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
0
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
price (yen / kg)
price (yen / kg)
market price albacore
fresh
fresh
panel) in Japanese fishing ports (155 ports in 2011).
17
flozen
600
400
200
market price bigeye
flozen
2000
1500
1000
500
Fig. 13 Historical changes of market price of frozen and fresh for albacore (upper panel) and bigeye (lower
catch*price (frozen)
120000
catch (total)
2011
2009
2007
2005
2003
2001
1999
1997
1995
1993
1991
0
1989
30000
1987
10000
1985
60000
1983
20000
1981
90000
1979
30000
amount of catch (ton)
40000
1977
amount of catch*price (x 1000)
albacore
0
catch (total)
200000
2011
2009
2007
2005
2003
2001
1999
1997
1995
1993
1991
0
1989
50000
1987
50000
1985
100000
1983
100000
1981
150000
1979
150000
amount of catch (ton)
catch*price (frozen)
200000
1977
amount of catch*price (x 1000)
bigeye
0
Fig. 14 Historical changes of products of market price of frozen and total catch for albacore (upper panel)
and bigeye (lower panel). The amounts of catch are total yield caught by Japanese fishing vessel of any
fisheries in the North Pacific Ocean (north of equatorial).
18
total catch
ALB
150,000
amount of catch (ton)
BET
YFT
100,000
50,000
2004
2006
2008
2010
2012
2004
2006
2008
2010
2012
2002
2000
1998
1996
1994
1992
1990
1988
0
total amount of import
amount of import (ton)
150,000
100,000
50,000
2002
2000
1998
1996
1994
1992
1990
1988
0
Fig. 15 Recent trends of total catch of Japanese fishery (upper panel), total amount of import by species of
Japan (lower panel).
19
Appendix 1 Geographical distribution of effort (x 1000 number of hooks; upper panel) and
number of albacore (x 1000 fish; lower panel) of large vessel (>20 GRT) four periods (before
1974, 1975 to 1992, 1993 to 2002 and after 2003).
20
Appendix 2 Geographical distribution of effort (x 1000 number of hooks; upper panel) and
number of albacore (x 1000 fish; lower panel) of small vessel (10-20 GRT) four periods (1994
to 2002 and after 2003).
21
Appendix 3 Annual average biomass of bigeye by region of western central Pacific Ocean (from figure 36
of Davies et al (2011)). The region 1 is vicinity of Japan. The regions 3 and 4 are tropical area, main fishing
ground for bigeye.
22
Appendix 4 Annual spawning biomass of bigeye of eastern Pacific Ocean (from figure 5 of Aires-da-Silva
and Maunder (2012a)). The black solid line indicates spawning biomass with fishing.
Appendix 5 Annual spawning biomass of bigeye of the Indian Ocean (from figure 11 of Nishida and
Rafemeyear (2011)).
Appendix 6 Annual changes of relative abundance of bigeye of the Atlantic Ocean (from BET-figure 5 of
Anonymous ICCAT (2012b)).
23
Appendix 7 Annual average biomass of yellowfin by region of western central Pacific Ocean (from figure
46 of Langley et al (2011)).
Appendix 8 Annual spawning biomass of yellowfin of eastern Pacific Ocean (from figure 5 of Aires-daSilva and Maunder (2012b)). The black solid line indicates spawning biomass with fishing.
Appendix 9 Annual spawning biomass of yellowfin of the Indian Ocean (from figure 31 of Langley et al
(2012)).
24
Appendix 10 Annual changes of relative abundance of yellowfin of the Atlantic Ocean (from figure 17 of
Anonymous ICCAT (2011)).
25