LONG LONG - - TERM VARIABILITY OF PELAGIC FISH SPECIES COMPOSITION TERM VARIABILITY OF PELAGIC FISH SPECIES COMPOSITION NEAR THE SAKHALIN (SEA of OKHOTSK): DISTRIBUTION, NEAR THE SAKHALIN (SEA of OKHOTSK): DISTRIBUTION, FLUCTUATIONS IN ABUNDANCE, FISHERY FLUCTUATIONS IN ABUNDANCE, FISHERY A. A. Ya Ya . Velikanov, SakhNIRO, Russia . Velikanov, SakhNIRO, Russia e e - - mail: velikanov@ mail: velikanov@ sakhniro.ru sakhniro.ru
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LONG-TERM VARIABILITY OF PELAGIC FISH SPECIES …€¦ · Sakhalin South-eastern Sakhalin Aniva Bay, La Perouse Strait South-western Sakhalin North western Species Sakhalin. Species
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LONGLONG--TERM VARIABILITY OF PELAGIC FISH SPECIES COMPOSITION TERM VARIABILITY OF PELAGIC FISH SPECIES COMPOSITION
NEAR THE SAKHALIN (SEA of OKHOTSK): DISTRIBUTION, NEAR THE SAKHALIN (SEA of OKHOTSK): DISTRIBUTION,
FLUCTUATIONS IN ABUNDANCE, FISHERYFLUCTUATIONS IN ABUNDANCE, FISHERY
A. A. YaYa. Velikanov, SakhNIRO, Russia. Velikanov, SakhNIRO, Russia ee--mail: velikanov@ mail: velikanov@ sakhniro.rusakhniro.ru
Sakhalin Island
56532Number of planktivorous species with biomass >100 000 t
787–865Number of planktivorous species with biomass >10 0000 t
Species composition (+, species present; –, species absent) of pelagic and demersal planktivorous fish in different areas off Sakhalin Island (adapted from Lindberg, 1959; Borets, 1997).
Species composition (+, species present; –, species absent) of pelagic and demersal planktivorous fish in different areas off Sakhalin Island
(adapted from Lindberg, 1959; Borets, 1997).
AnadromousPelagicDemersal
Б
AnadromousPelagicDemersal
В
AnadromousPelagicDemersal
Г
AnadromousPelagicDemersal
Д
A
B
D
E
C
Proportion of pelagic, anadromous and
demersal
species in the epipelagic fish
communities in different regions of eastern S a k h a l i n : 1947-1997 -
Distribution of herring along the eastern Sakhalin coast (from left to right: October 2002; July 2002; August 2003; September-October 2004)
Length-size composition of herring trawl catches near northeastern Sakhalin: Left –
July 2002 (A); October 2002 (B); right –
June 2007
A
B
1 4 3 1 4 4 1 4 5 1 4 64 8
4 9
5 0
5 1
5 2
5 3
5 4
1 0
5 0
1 0 0
5 0 0
1 0 0 0
5 0 0 0
142.5 143.0 143.5 144.0 144.5 145.0 145.546.00
46.50
47.00
47.50
48.00
48.50
49.00
49.50
1
5
10
50
100
200
142.0 142.5 143.0 143.5
45.40
45.90
46.40
46.90
0.5
1
5
10
20
143°00' 144°00' 145°00' 146°00'
49°00'
50°00'
51°00'
52°00'
53°00'
54°00'
0.01
0.1
1
10
100
350
т/кв.милю
143 144 145
47
48
49
50
51
52
53
0.1
0.5
1
5
10
15
20
21
Ðèñ.3.1 - Ðàñï ðåäåëåí èå ì èí òàÿ ó âî ñòî ÷í î ãî Ñàõàëèí à â ñåí òÿáðå-î êòÿáðå 2004 ã. (ò/êâ.ì èëþ )
1
100
1000
5000
10000
21000
êã/êâ.êì
143°00' 144°00' 145°00' 146°00'49°00'
50°00'
51°00'
52°00'
53°00'
54°00'
55°00'
.
Distribution of walleye pollock near the eastern Sakhalin coast in 2002 (from left to right: northeastern Sakhalin, September-October; southeastern Sakhalin and
Aniva Bay, August-September).
Distribution of walleye pollock near the northeastern Sakhalin coast (from left to right: August 2003, October 2004 and 2005)
X=3.12
02468
1012141618
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Ряд1
X=8.83
0
5
10
15
20
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Ряд1
X=15.63
0
5
10
15
20
25
30
35
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Ряд1
X=11.25
0
5
10
15
20
25
30
35
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Ряд1
D
Dynamics of abundance index of pink salmon in different regions of eastern Sakhalin in 1996-2005 (top-down: northeastern Sakhalin; Terpeniya Bay; southeastern Sakhalin;
Aniva Bay).
142.00 143.00 144.00 145.00 146.00 147.0045.00
46.00
47.00
48.00
49.00
50.00
51.00
52.00
53.00
54.00
55.00
- улова нет- 0.01-5.0 кг/час траления
- 5.1-10.0 кг/час траления
- 10.1-50.0 кг/час траления
- 50.1-110.0 кг/час траления
142 143 144 145 146 147 148 14944
45
46
47
48
49
50
51
52
53
54
55
нет1-5051-100101-10001001-50005001-20000
Улов, шт/траление
143 144 145
47
48
49
50
51
52
53
0.005
0.01
0.05
0.1
0.2
0.3
0.4
0.41
Ðèñ.3.4 - Ðàñï ðåäåëåí èå ì î éâû ó âî ñòî ÷í î ãî Ñàõàëèí à â ñåí òÿáðå-î êòÿáðå 2004 ã. (ò/êâ.ì èëþ )
Distribution of capelin near the eastern Sakhalin coast (from left to right: pelagic trawl survey -
Distribution of sand-lance near the northeastern Sakhalin coast in September-October 2002 (bottom trawl survey)Photo of sand –lance from pelagic trawl catches near
the
northeastern Sakhalin coast in
July 2002
Distribution of sand-lance in Aniva Bay and La Perouse Strait in June 2004 (left fig.) and 2006 (bottom trawl survey)
Distribution of sand-lance inshelf waters of Sakhalin Island
Distribution of juvenile sand-lance in Aniva Bay and adjacent waters in June-July 2002-2004 and
in July 2008 (top-down)
Occurrence and pelagic trawl catches of juvenilesand-lance in Aniva Bay and adjacent waters in June-July 2002-2008
Length composition of the bottom trawl catches
of sand–lance in the La Perouse Strait in June
2004 and 2006 (top) and in June-August 1976, 1982 and
1985 (bottom)
Year Aniva Bay South-Eastern Sakhalin
Egg concentration (х106
egg/m2)Spawning area (х106 m2)
Egg concentration (х106
egg/m2)Spawning area (х106 m2)
1979 3,14 –
15,90 0.60
1985 0.51-3.66
1986 0.26 –
0.67
1987 0.05-
1.28 0.50 0.08 -0,17 0.51
1988 0.01 –
2.10 0.71 0,01 –
8.77 0.89
1989 0.01 –
3.18 0.64
1985-1989 0.01 –
3.66 0.5-0.71 0.01 -
8,77 0.51-0.89
2000 0.004 –
0.145 0,30 –
0.70 0.50
2001 0.002 –
0.110 0,05 –
0,40 0.40
2002 0.049-
2.025 0.20 0.10 –
1,01 0.60
2003 0.009-
1.452 0.09 0.05 –
0.20
2004 0.007 –
0.196 0.15 0,01 –
0,19
2000-2004 0.002 –
2.025 0.09-0.20 0,01 –
1,01 0.40-0.60
Data of capelin spawning area and eggs concentration in Aniva Bay and near southeastern Sakhalin in different years
0
50
100
150
200
250
300
350
400
1950
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
Х 1000 тонн
0
20
40
60
80
100
120
1951
1955
1959
1963
1967
1971
1975
1979
1983
1987
1991
1995
1999
2003
2007
X100
0 to
ns
0
20
40
60
80
100
120
140
160
180
200
1952 1957 1962 1967 1972 1977 1982 1987 1992 1997
Года
Улов, тыс
.тонн
0
5
10
15
20
25
1940
1950
1960
1970
1980
x 10
000 t
Ряд1
0
50000
100000
150000
200000
250000
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
Tons
0
50
100
150
200
250
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
X10
tons
Pink salmon
Sand-lance
Arabesque greenling
Walleye pollock
Pacific sardine
Herring
Dynamics of different pelagic fish catches in the southwestern part
of the Sea of Okhotsk in the second half of the 20th century
Abundance and Fishery
In the 20th century total maximal annual catches of herring, Pacific sardine, sand-lance, walleye pollock and pink salmon reached 1,0 million tons near the eastern Sakhalin. Long-term abundance fluctuations of northern and southern boreal species were characterized by comparatively smooth changes, which had been observed during 50-60 years. The time periods when high abundant subtropical species appeared in the investigation area were shorter, not more than 10-20 years.
Summary
•
Essential changes in species composition, distribution, abundance and annual catches of pelagic fishes took place in the Sea of Okhotsk near the Sakhalin Island during 1950 –
2008.•
At present, walleye pollock, herring and sand-lance are mostly abundant in the northern part of the study area (49 -
54°
N), whereas pink salmon, capelin, arabesque greenling and Japanese anchovy –
in the southern part (46 -
49°
N).•
The productivity of the southern spawning grounds for herring, walleye pollock, sand-
lance and capelin declined significantly during the last 30 years, whereas the productivity of pink salmon spawning grounds in Sakhalin southern rivers increased.
•
In 1990-2008 reproduction of Japanese anchovy and arabesque greenling was at the high level. Annually these species form feeding aggregations near the southeastern Sakhalin, but their spawning grounds are located far south of Sakhalin Island.
•
In the 20th century total maximal annual catches of herring, Pacific sardine, sand-
lance, walleye pollock and pink salmon reached 1,0 million tons near the eastern and southern Sakhalin.
•
Long-term abundance and catches fluctuations of boreal and subtropical pelagic fishes have essential difference in the Sea of Okhotsk near Sakhalin Island. Boreal species were characterized by comparatively smooth changes, which had been observed during 50-60 years. The time period when high abundant subtropical species appeared in the investigation area was shorter, not more
than 10-20 years•
A new wave of south-latitude fish migrations took place near the Eastern Sakhalin in
2000-2008; there were recorded almost 10 various species, including white shark, which was caught for the first time in Aniva Bay in 2007.
•
All above-mentioned changes in the epipelagic fish communities are related
with long-term changes in climate and oceanological regime.