Thispaper not to be cited without prior reference to the author . International Council for
the Exploration of the Sea
"fi t Preliminary Report of the International 0-group fish survey in the Barents Sea and adjacent waters in August-September 1972 .
INTRODUCTION
This was the eighth in a series of international surveys to study the abundance of 0-group fish in the Barents Sea and the Svalbard region .
The following vessels and scientists took part in the survey : USSR R/V "Akademik Knipovich", V .N .Schlainik
R/V "Fritjof Nansen", V .N .Kusnets,ov
R/V "Poisk", A .S .Seliverstov, V .K .Nethaev Norway : "Johan Hjort", T .Monstad, R .Saetre, O .Smedstad
"G .O .Sars", L .Midttun, P .Hognestad, O .Nakken
R .Sarynina and O .Dragesund participated in the preparation of the report .
Preliminary plans for the survey were made at a meeting in Bergen i May 1972, and final arrangements for coordination were made in Kirkenes and Murmansk immediately before the
commencement of the survey . The main part of the survey were carried out between 27 August and 11 September but "Akademik Knipovich" commenced somewhat earlier . The survey was
followed by a meeting at sea on 13 September . Material was exchanged and a brief report worked out, based on a rather superficial analysis of the data . The final version of this report was agreed upon at a meeting in Moscow in November 1972 .
C . M .1973/H :15
Pelagic Fish (Northe. rn) Committee Ref : Hydrography and Demersal Fish (N) Committees .
MATERIAL AND METHODS
The distribution and density of the pelagic scattering layers was estimated from echo sounder paper records but also to
some extent from echo integrator measurements . The organisms forming the scattering layers were identified by sampling with small meshed pelagic trawls . Various depth metering devices on the trawl were used for the accurated control of the trawling depth . Since different trawl types were used by the different vessels, a direct quantitative comparison between catches
could not be made .
Fig . 1 shows the area surveyed and the ship's tracks together with trawl and hydrographic stations worked .
RESULTS
Hydrography
Hydrographic observations were carried out along the same
standard sections as in previous years . A preliminary analysis of the data made it possible to conclude the following
(Fig . 2-7) : In the summer of 1972 the heat content in the Barents Sea was extraordinarly high . At the end of August the mean temperature in the 0-50 m layer on the Kola section
reached 8 .7 ° C, which is the highest value observed during the last 27 years . Due to this high heat content in the upper 50 m, the mean temperature in the 0-200 m layer proved to be higher than ever measured before during the 8 years-period of
international 0-group surveys in the Barents Sea (Table 1) .
TABLE 1
Mean water temperature . i n the Murman Current, the Kola section at the end of August in the years 1965-1972 .
Year 1965 1966 1967 1968 1969 1970 1971 1972 Layer
0- 50m 6 .7 6 .7 7 .5 6 .4 6 .7 7 .8 7 .1 8 .7 50-200m 3 .8 2 .6 4 .1 3 .7 3 .1 3 .6 3 .2 4 .0 0-200m 4 .6 3 .6 4 .9 4 .4 4 .0 4 .7 4 .2 5 .2
3
The heat content in the 0-200 m layer in the North Cape Current, north of the North Cape, was also higher than in previous years
(Table 2) .
TABLE 2
In contrast to what was observed in the Murman and North Cape Currents, the temperature in the Norwegian Current, West of Bear Island, was lower than in 1971 . This was the case in both
the 0-50 m layer and in . the 0-200 m layer . Thus the waters of the North Cape and the Murman Currents were considerably warmer compared to previous years than the water masses of the
Norwegian and West-Spitsbergen Currents .
The main reason for the large heat content of the water masses in the North Cape and Murman Currents was the high solar
heating during the whole summer of 1972, and not an increased advection of warmer water masses into the Barents Sea .
Distribution and abundance of 0-group fish .
The distribution and density of the scattering layers is shown in Fig .8 and 9 . The echo records do not include other age group fish but there might be some contribution from inverte- brate organisms . The echo abundance is as usual expressed on a subjective scale from 0-4 (Fig .8) . However, this year a distribution chart based on echo integrator deflections was also prepared (Fig .9) . Integrator deflection is proportional to fish density . Length distribution based on all catches of the most important species is shown in fig .10 .
Mean_ water temperature in the North Cape Current, the North Cape - Bear Island section at the beginning of September
in
.the years 1965-1972 .
Year 1965 1966 1967 1968 1969 1970 1971 1972 Layer .
0-200 m 5 .1 5 .5 5 .6 5 .4 6 .0 6 .1 5 .7 6 .3
In the following we shall give short comments on the abundance of the different species observed (Fig .ll-17) . Filled symbols indicate catch .
Herring
No 0-group herring were recorded this year .
Cod
0-group cod were distributed over a rather wide area both in central and eastern parts of the Barents Sea and also along
the western and north-western Spitsbergen shelf,(Fig .ll) . The total area of distribution was hardly covered this year, since the cod had an unusual far easterly and northerly distribution within the circulation system . The abundance is considered
to be of the same magnitude as in 1971, i .e . somewhat above average .
Haddock
The haddock were found in the western Barents Sea and along the west coast of Spitsbergen (Fig .l2) . This year the abun- dance was estimated to be low compared with the years 1969-1971 .
Redfish
The distribution area of redfish was found to be similar to that in 1965 and 1971, being located in the western Barents Sea and northwards along the western Svalbard shelf (Fig .13) . The 1972 yearclass was considered to be somewhat stronger than the yearclasses of 1965 and 1971 but weaker than the rich 1969 yearclass .
Capelin
The 0-group capelin were distributed over the total Barents Sea south of latitude 77°N and within a ; smaller area west of Spits- bergen (Fig .14) . The exact northern limit of distribution
was not fully described by this years field coverage . The 4
1
density varied much and the highest concentrations were found west of Novaya Zemlia and near the Bear- and Hope Islands . The abundance of young capelin . (0- and .1-group) can be con-
sidered as being high . A part of the recorded capelin origi- nated from the spawning in 1971 . This is indicated by the
length distribution in Fig .10 . The 1971 yearclass must be classified as rich, and is probably comparable to the 1967 and 1969 yearclasses . Judging from the large area of distribution
(Fig .14) the 1972 yearclass also seems to be rich . Long rough dab
The 0-group long rough dab were . found within three separate areas as seen from Fig .15 . The abundance this year was appearently low .
Polar cod
According to observations from R/V "Akademik Knipovich" the polar cod was found to be abundant in the Novaya Zemlia area, but in the other parts of the area covered, the abundance was
low (Fig .16) . However, as a conclusion, the 1972 yearclass is considered to be strong, probably of the same order as the 1969 . It should also be noted that the distribution in the southern Barents Sea was more south-easterly than in previous years .
Other species
Fig .l7 indicate observations of three other species, viz . : Greenland halibut, mackerel and saithe . These species were
found only in small quantities . Smaller quantities of sea
.scorpions-, . squids and lumpsucker were also observed . The abun- dance of sea scorpions was probably somewhat higher this year
than in 1971 . Adult fish
5
The observations of adult fish during the 0-group survey have not been reported in this paper, but will be dealt with in national reports .
0
4-
2
0
8
Z-Z-az-za--
A 0
Z-Z
A A A Ax\
AX A \
Z--*Z b
A z
X-X
7
z x AZ X
:
AX X
I.
I A . x410
.
AX A A .
~X-X XAx
Z-dz-AZ-z-
A A
A A
x A
Z x
Q
X A
A
x
x I. .
AX / . :
I +~
AX-xx . f
X6--&x / A AX X
X 0/
XQ p (-X G X
XxX~X~
y6
~ o
.
31(
i x
t
s AAX AX AX
A A
,;
~w
0
26 AUG .- 10 SEP. 1972 o HYDROGRAPHY
x BATHY THERMOGRAPH z STD-SONDE
a PELAGIC TRAWL o BOTTOM TRAWL
10° 20° 30° 40°
Fig . 1 . Survey routes and grid of stations .
50 ° 60 °
. -
a°
0°
01
4 5
4
234
o 1 2
0
4l
t°C 100M
0 -1
.`
't A, 1
3
t°C 200M
~D b4ob
6 6
Fig . 4 . Isotherms at 100 m .
Fig . . Temperature section Bear Island - North Cape .
Fig . 7 . Temperature section Bear Island .- West .
8'
°
.I llllgi[: : "
G
. .. .. .. .. . .. .. .. ..
p lv'
ECHO RECORDINGS .""""' VERY SCATTEREDSCATTERED
111131r DENSE
> c VERY DENSE 0
1
OD 00
0.
6°
8°
10°
Fig . 8 .
20° 300 400
Total echo recordings of 0-group fish .
0 105
0 10 25
5 10 25
10°
5
100
25 10
50 25
TOTAL INTEGRATOR VALUES (MM DEFLECTION) OF 0-GROUP FISH
5 10 105
0 25
, - f
Fig . 9 . Total integrator \7a l 11PG (mm - .- ; - .-
50 ° 60 °
a 40
20
40
20
40
w 20
0a zw
0 a U 40
20
40
20
40
20
40
20
20 40 60 80 100 120 140 M M
Fig . 10 . Length distribution of 0-group fish .
I I
1
I
COD . N = 2121
I
1I II
I . I II I .
HADDOCK N=221
I
1 i
REOFISH N = 4554
I
, I
I I I
CAPELIN N=10850 . .
i
I 1
I I
LONG ROUGH DAB N=323
I I
I I
POLAR COD SVALBARD
N = 309
I
I I
; , i i i
POLAR COD NOVAJA ZEMLJA N = 3043
Fig . 11 . Distribution of 0-group cod .
10 ° 20° 30 ° 40 ° 50 ° 60 °
Fig . 12 . Distribution of 0-group haddock .
8
60•
20
0°
/ /
16
0-GROUP REDFISH
A PELAGIC TRAWL o BOTTOM TRAWL
A A
Am A AA G' A A A A A A A A AA A A A 0A
A
A A
A A A A A A A
4 A A
A A A
A A A A
A A AA
A A A A A A
A A
p a AA A A A A A A A AA A A A A A A
AA A
A AA
AA A A
Fig . 13 . Distribution of 0-group redfish .
80°
a
4.
Fig . 15 . Distribution of 0-group long rough dab .
a name
0-GROUP LONG ROUGH DA PELAGIC TRAWL
o BCTTOM TRAWL
0-GROUP POLAR COD a PELAGIC TRAWL
BOTTOM TRAWL
0
8
D
Q ooc
DO
A//
® 0-GROUP SAITHE O 0-GROUP MACKEREL
•
0-GROUP GREENLAND HALIBUT
0
PELAGIC TRAWL o BOTTOM TRAWL
Fig . 17 . Distribution of 0-group saithe, mackerel and Greenland halibut .
0
