Historical Trends of Salmon Fisheries and Stock Conditions in Japan
Osamu Hiroi
Research Division, National Salmon Resources Center
2-2 Nakanoshima, Toyohira-Ku, Sapporo 062, Japan
Hiroi, Osamu. 1998. Historical trends of salmon fisheries and stock conditions in Japan. N. Pac.
Anadr. Fish Comm. Bull. No.1: 23-27
Artificial salmon hatchery operation in Japan can be described from various aspects such as
salmon resources, resources management, economic effects, and future prospects. Almost all the
salmon resources in Japan have been supported by artificial propagation. Recent annual total salmon
catch increased to about 300 thousand tons, in which the coastal catch accounted for over 80 percent.
With regard to the species composition of commercial catch, the chum catch is the largest, about 230
thousand tons (about 80 percent). Resource management coupled with active propagation made the
set net fishery for chum and pink salmon stable. Economic returns from harvesting (about 50-80 billion
yen) in the coastal fishery vis-a-vis expenses (about 10-14 billion yen) for artificial propagation of
salmon is about 5-8 times.
INTRODUCTION
Almost all the salmon resources in Japan have
been supported by artificial propagation. Species
subject to artificial propagation programmes in Japan
are: chum salmon (Oncorhynchus keta), pink salmon
(0. gorbuscha), masu salmon (0. masou) and
kokanee salmon (0. nerka). Smolt cultured from the
lake-living kokanee, a land-locked sockeye salmon,
have been released on a pilot basis in natural rivers
with a view to developing sockeye resources. Only
a limited number of chinook salmon (0.
tschawytcha), coho salmon (0. kisutch) and sockeye
salmon (0. nerka) are caught in the coastal sea or the
North Pacific Ocean. Coho salmon are becoming
cultured in cages or in freshwater ponds. To promote
efficient artificial propagation of salmon, it is
important to make a model of some aspects of
behaviour in the life cycle of the fish, especially those
concerned with spawning migration, spawning,
breeding, development, smoltification, downstream
migration and feeding migration.
EFFECTS ON RESOURCES
Annual Catches of the Japanese Salmon Fisheries
Annual catches of the Japanese salmon fishery
are shown in Table 1. Total catches of salmon
fluctuated between 100-160 thousand tons from 1965
to 1982, and increased to over 170 thousand tons
since 1983, reaching about 303 thousand tons in 1995
in spite of a gradual decrease in the distant water
catches, from 120 to 12 thousand tons, following to
the cease of salmon fisheries among open areas of the
North Pacific Ocean since 1990. Almost all the
coastal catch comes from artificial propagation in
Japan. The percentage of coastal catch has increased
to over 60 percent since 1979 and over 80 percent
since 1986. Since 1981, the total annual commercial
catch has been 112-231 thousand tons (73-85 percent)
for chum, 12-35 thousand tons (5-16 percent) for
pink, 2.5-4.0 thousand tons (0.9-2.5 percent) for
masu, 0.5-7.8 thousand tons (0.2-3.3 percent) for
sockeye, 3.2-26.0 thousand tons (1.9-12.1 percent)
for coho and 0.3-1.4 thousand tons (0.1-0.9 percent)
for chinook. Recently, production of pen-cultured
coho salmon has increased to 25 thousand tons in
1991-2 (see Table 1).
Annual Adult Returns and Return Percentage jor
Salmon Released from Japan
Annual adult returns for chum released from
Hokkaido and Honshu Islands are shown in Table 2
and Figure 1. The numbers of chum fry released
from both Hokkaido and Honshu Islands, have
increased to 1900 from 470 million fish, from 1965
to 1981, and have stabilized at about 2000 million
fish since 1982. Adult returns to rivers and coastal
Table 1. Annual catches in the Jaeanese salmon fishe!1.
Year
Far-seas catch
(thousand
tons)
126.8
110.1
128.3
102.2
122.1
95.8
102.3
92.6
97.2
88.5
92.8
84.4
64.3
42.7
43.5
43.4
43.2
43.6
43.3
36.4
35.5
20.9
20.5
15.5
18.4
11.9
16.5
23.4
26.1
23.8
33.0
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
Coastal Sea
catch
(thousand
tons)
Freshwater
catch
(thousand
tons)
18.8
16.5
20.1
11.6
19.2
22.1
37.0
27.0
38.8
44.0
66.5
41.7
52.2
60.1
87.5
79.1
106.6
92.7
117.8
120.9
167.6
146.5
140.2
151.8
173.7
211.3
198.2
155.9
204.0
216.1
251.0
3.6
2.2
3.0
1.4
2.0
1.9
2.6
2.0
3.0
2.9
7.0
3.9
3.7
4.1
6.5
9.4
8.9
9.3
9.0
9.0
11.4
10.0
8.6
10.8
13.3
15.9
13.4
10.2
14.4
21.1
19.3
Total
(thousand
tons)
Percentage of
coastal catch
149.2
128.8
151.4
115.2
143.3
119.8
141.9
121.6
139.0
135.4
166.3
130.0
120.2
106.9
137.5
131.9
158.7
145.6
170.1
166.3
214.5
177.4
169.3
178.1
205.4
239.1
228.1
189.5
244.5
261.0
303.3
12.6
12.8
13.3
10.1
13.4
18.4
26.1
22.2
27.9
32.5
40.0
32.1
43.4
56.2
63.6
60.0
67.2
63.7
69.3
72.7
78.1
82.6
82.8
85.2
84.6
88.4
86.9
82.3
83.4
82.8
82.8
Pen-culture
coho (thousand
tons)
0.1
0.4
1.9
1.2
2.1
2.8
5.0
7.0
7.5
12.2
16.5
19.8
23.6
25.7
25.5
21.1
22.8
15.0
Table 2. Annual chum salmon runs {thousandsl to Hokkaido and Honshu.
Hokkaido
Year
Coastal
Sea
Rivers
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
'1989
1990
1991
1992
3408
3908
1902
3595
4651
6806
6343
7724
9026
14217
8342
9466
12284
17751
13786
20296
18270
21235
19741
29461
26218
26560
32514
34973
41210
39071
26014
37220
46986
53793
396
592
236
578
627
845
614
597
601
1557
463
742
863
1151
1660
1630
1770
1778
1831
2413
1999
1567
2315
2903
3264
2390
1534
2789
4204
3899
1993
1994
1995
Honshu
Total
3804
4500
2138
4173
5278
7651
6957
8321
9627
15774
8805
10208
13147
18902
15446
21926
20040
23013
21572
31874
28217
28127
34829
37876
44474
41461
27548
40009
51190
57692
Coastal
Sea
Rivers
451
370
260
313
424
652
698
616
901
1463
1361
1873
2667
4518
5873
7251
7448
10052
15880
16559
19206
13937
15489
15722
22171
17346
17180
19407
16211
18395
187
142
115
134
149
245
229
238
224
362
271
374
394
608
1099
727
894
776
895
888
1201
837
968
991
1539
1353
1164
1357
1468
1690
Total
Total
638
512
375
447
573
897
927
854
1125
1825
1632
2247
3061
5126
6972
7978
8342
10828
16775
17447
20407
14774
16457
16713
23710
18699
18344
20764
17679
20085
Coastal
Sea
Rivers
Total
3859
4278
2162
3908
5075
7458
7041
8340
9927
15680
9703
11339
14951
22269
19659
27547
25718
31287
35621
46020
45424
40497
48003
50695
63381
56417
43194
56627
63197
72188
583
734
351
712
776
1090
843
835
825
1919
734
1116
1257
1759
2759
2357
2664
2554
2726
3301
3200
2404
3283
3894
4083
3743
2698
4146
5672
5589
4442
5012
2513
4620
5851
8548
7884
9175
10752
17599
10437
12455
16208
24028
22418
29904
28382
33841
38347
49321
48624
42901
51286
54589
68184
60160
45892
60773
68869
77777
Fig. 1
Annual changes in adult returns and released fry for chum salmon from Japan, 1965-1995.
80000 .......- - - - - - - - - - - - - - - -.....3000
[] ADULT RETURNS IN HONSHU
.-
•
C/)
"0
-oen
ADULT RETURNS IN HOKKAIDO
a; 60000
c
C/)
2000 ~
E
::l
o
-
-
.c
..,
C/)
c::
:10..
~
40000
"'C
::l
Cl)
Q)
1000 ~
:10..
Cl)
320000
Q)
ex:
"0
«
o
1965
1970
1975
1980
1985
1990
o
1995
Year
seas totalled over 10 million fish 1974, over 20
million fish since 1979, over 30 million fish since
1983, over 40 million fish since 1985, over 50
million fish since 1988 and over 60 million fish
since 1990 (except 1992). The largest return,
about 78 million fish, was seen in 1995. Over 70
million fish are also expected in 1996. Annual
chum fry to adult return rate by brood year for
chum released from Hokkaido and Honshu Islands
are shown in Table 3. The adult return rate has
stabilized at over 2 percent since 1968, over 3
percent since 1984 and over 4 percent since 1987
except 1988 in Hokkaido, and between 1.6-2.5
percent since 1975 in Honshu. Recently, the
largest return rate in Japan has been estimated at
about 3.8 percent in 1991. In one local stock of
Hokkaido, a return rate over 13 percent was
recorded. The recent rapid increase in adult
returns and return rates are due not only to an
increase in the number of fry released by expansion
and improvement of hatchery facilities, but also to
effective use of spring waters and full protection of
river fish from coastal fishing, and prolonged
feeding periods (two to five months) prior to
release.
Annual changes in adult returns and the return
rates of pink salmon from Hokkaido are shown in
Table 4 and Figure 2. The numbers of released
pink fry have fluctuated between 16 to 150 million
fish from 1969 to 1986, and have been regulated at
120-150 million fish since 1987. The adult returns
to rivers and coastal seas fluctuated between 0.42.7 million fish with a clear trend of increasing in
odd years and of decreasing in even years from
1969 to 1986. Without a difference in odd years
and even years, they increased to over 3.8 million
fish since 1987 except 1990 and over 8 million fish
since 1991. The largest return, about 17 million
fish, was seen in 1994. In 1996, they expect over
19 million fish. The adult return rate for pink fry
released from Hokkaido has stabilized at over 5
percent since 1989. The largest return rate, about
12 percent, was seen in the 1992 brood.
For the masu salmon in Hokkaido, since 1986,
3. 1-8.0 million fry or smolts have been liberated
and 264-869 thousand adults have been caught in
the coastal seas near the home stream,
corresponding to a return rate of 8-28 percent.
For the sockeye salmon, since 1982, 31-2015
thousand fry or smolts have been liberated and 0.48.2 thousand adults have been caught in the coastal
seas near the home stream, corresponding to a
roughly return rate of 0.1-2.5 percent.
RESOURCE MANAGEMENT
To promote an effective use and adequate
control of salmon resources maintained by artificial
production, it is necessary to keep an appropriate
Table 3. Annual chum fry to adult return rates by brood year. Figures in brackets indicate number or rate of adult returns
after four lears.
Hokkaido
Honshu
Year
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
19n
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
Liberated Fry
(thousands)
Adult
Returns
(thousands)
Liberated
Fry
(thousands)
1,08
1,83
0,63
0.47
2.18
1.87
2.35
2.42
2.29
2,24
2.50
2,03
2.34
2.66
2.50
3.01
3.07
2.15
2.34
2.96
2.47
2.47
3.09
3.70
3.72
4.10
2.89
4.14
(4.61)
(5.45)
3025
4983
2119
2572
5943
8110
4881
8737
10110
12913
11909
9036
11342
21322
13092
20872
23917
18809
26810
31919
28326
28330
35154
41855
39864
43283
31753
46438
(50705)
(57277)
280743
272106
334463
549278
272036
434729
207438
361571
442101
575986
475805
445510
484849
801991
523221
693222
779269
873489
1146346
1079708
1145880
1146763
1139496
1131739
1072605
1054616
1097165
1122345
1100957
1051520
1008750
1083954
1053813
Return
Rates (%)
138267
116476
139575
109836
196469
161240
121193
139536
144673
222516
224946
271223
271708
343988
287133
412625
433177
589905
750113
738055
864601
885534
895018
910476
927853
937447
972496
945954
993257
989287
950878
968786
955940
Adult
Returns
(thousands)
(718)
(572)
(415)
(497)
(653)
(987)
(1017)
(1004)
(1275)
1351
1898
2588
2414
5546
6889
7422
8341
10174
(17085)
(17693)
(20393)
(14769)
(16448)
(16709)
(23247)
(19044)
(18646)
(20652)
(18164)
(20501)
Return
Rates (%)
(0.52)
(0.49)
(0.30)
(0.45)
(0.33)
(0.61)
(0.84)
(0.72)
(0.88)
0.61
0.84
0.95
0.89
1.61
2.40
1.80
1.93
1.72
(2.28)
(2.40)
(2.36)
(1.67)
(1.84)
(1.84)
(2.51)
(2.03)
(1.92)
(2.18)
(1.83)
(2.07)
Table 4. Annual adult returns and the return rates for pink salmon from Hokkaido. Figure in bracket indicates a number
reE!orted en route.
Adult returns (thousands)
Return rate
Liberated Fry
Year
(thousands)
(%)
Rivers
Total
Coastal Sea
1969
1970
1971
1972
1973
1974
1975
1976
19n
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
64556
15873
139687
20390
89091
52460
65864
37558
50390
23398
69433
27918
102703
57277
152790
100290
135414
127998
142085
140968
148953
134598
140824
137847
139821
117920
858
329
2535
470
2048
1115
1484
1054
710
719
597
796
1370
762
1051
1110
2116
1499
2987
3320
3386
2222
7041
8469
7543
15481
9035
(17004)
103
43
274
51
202
122
147
88
116
47
153
68
193
120
378
266
590
396
841
544
600
375
1174
950
387
1907
820
(2143)
961
372
2809
521
2250
1237
1631
1142
826
766
750
864
1563
882
1429
1376
2706
1895
3828
3864
3986
2597
8215
9419
7930
17388
9855
(19147)
4.35
3.28
1.61
6.07
1.83
2.18
1.25
2.04
1.49
3.69
2.25
3.16
1.39
2.40
1.n
1.89
2.83
3.02
2.81
1.84
5.52
7.00
5.63
12,61
7.05
(16,24)
Fig. 2
-
Annual changes in adult returns and released fry for pink salmon from Japan, 1969-1996.
20000~--------------------------------~200
[] ADULT RETURNS
-
( f)
-
"C
RELEASED FRY
( f)
150 o
c::
.-
; 15000
(f)
:::::J
-o
E
.s::
( f)
c::
20-
-
100 ~
10000
"C
CD
:::::J
Q)
(f)
ca
20-
5000
50
CD
Q)
0::
O~~~~~~~~~.u~~u.~~~~.u~LO
1970
1975
1980
1985
1990
1995
Year
management of coastal commercial catches to
ensure that the adequate stock size returns to
rivers. Coastal maturing salmon migrating near
home streams are caught by several kinds of
fishery, set net and drift net, etc. Recently, the
share of set net fishery is the largest of those in
coastal commercial catches. Set net fishery for
chum and/or pink has increased both in number
of licenses issued and in earnings, coupled with
the rapid increase of resources. In Hokkaido,
to accomplish the adequate size of salmon runs
to secure the proper production capacity of the
resources, the Government has stipulated
various regulation such as fishery-term and
distance from shore for the chum and pink set
net fishery for each of the respective districts.
These regulations are subjected to review every
five years. In each year, moreover, temporary
removals of set net during the fishery season
have been required in cases where the level of
spawning run has been considered to be
inadequate. The adequate levels are estimated
for respective districts by resources analyses, on
the basis of the presumed number of adult
returns to both rivers and coastal seas. Thus,
the set net fishery for chum and pink, recently,
became stable thanks to resource management
with active propagations.
ECONOMIC EFFECTS
Expenses for the artificial propagation of
migrating salmon in Japan are Y 10-14 billion,
while harvests from the coastal catch of the
adult return are worth Y 50-90 billion, more
than five times the expense since 1985.
FUTURE EFFECTS
With regard to chum and pink salmon,
resources have reached a stable level by
artificial propagation, efforts to select adults
with a long freshwater life during anadromous
migration are now being paid for. These fish
take premium prices because of the silvery body
colour observed in coastal seas near home
streams. On the other hand, further efforts are
needed to increase resources for the districts or
prefectures with low level production and to
secure higher return rates.
With regard to masu and sockeye which are
among the most valuable species in the salmon
family, it is important to accomplish most
rapidly the artificial propagation technique by
using the smolt-release methods, to increase
resources, and to raise return rates.