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This pa;:eer no t t.,,) be ci ted without pE-ior reference to the author.

International Council for the E~loration of the Sea

C.H ..

1971/E:J2

Pelagic Fish (Northern) Committe 11ef:

Deme';r.sal Fish(Uorthern) Cooni tte Hydrography Committee

Preliminary ~eport of the International O-group fish survey in tl~e Barents Sea fu"'1.d adJacent ;;-mt~~. in Aug~t-Septemb...?r--.J..2.2!.

INTI~ODUCTIOH

TI~is was the seventh in a series of international surveys to study the abundance and distribution of O-group fish in the Barents Sea

ru~d the Svalbard region.

The follow'iug vessels and scientists took part in the survey:

USSR:

Norway:

R/V "Akade::1ik Iillipovichff R/V t!Fritjof' lTansen"

n/v

IIG.O.Sarslt

R/V ItJohan Ejort"

England: R/V "Cirolana"

A.S. Seliverstov 1 V~V.Penin1

V.n.Schleini.k1 V.D.Tesler, A.I.Lysota

O.Dragesund, P.T.Eognestad,

o

^{.1Ji.lT ald:::.en}

A. Hylen, 0 ~:M. 3meds tact, R. Sa3tre,

B.~.Jon9s, J.H.llichols, J.G.Pope, T.C~Doddington,

Preliminary pla::.1.s for tI:e survey ,vere ::lade at a cleeting in Bergen in Hay

1971,

and final arra::':J;:;ements for coordi2."?ation were made in T-.comS0 and HU:L~::1ru1.sl:::. itnt::rediately before the co;::.::'.ence('1ent of the survey. TI'le ;::!ain part of ti2e survey ^"Jas carried out betvleen

2:;

August aJ.1.d

9

Septeaber, but nA~:ademE:. ~0."lipovicl}Y commenced on 20 August. The survey '(·,(<"ts follo1ile.d by ^El r;lOe ti~G i::.1. Troms0 a during

10-13

Septe8ber arranged for tlle exchaJ."lge an.d analysis of' data.

HATERIAL AND HETEODS

As in previous years the distribution ru~d density or the pelagic scattering layers ,"vere estimated froo the echo sounder paper records, and the orgfu"'lisms formi::.1.g the s ca ttering layers:were identifieS. by sar.lpling ^vli th s;nall meshed pelagic tra1>{ls.' Various depth metering devices on the travlls ~>{ere used for tne accurate control of the depth of' trawling. Echo Integrators .-.rere used in conjunction 1Jith t~J.e echo sounders on board H/V "G .. O.Sars",

R/V flJohan I-Ijort", R/V tlCirolana^lf and R/V "Fri tjoi' H~...J.sen".

- 2 -

I t was thougnt that the different trawls used on the various ships probably had different fishing characteristics ffi"1.d i t was recommended

t~at for the future surveys a standard net should be selected and used by all ships in order to make quantitative comparisons of the

catcnes more reliable.

Fig.1 S11.O",lS the area surveyed and the ships' tracks together vIi th the tra1'IT1 and hydrographic stations w·orked.

HESULTS

Eydrographic observations were conducted on the standard sections:

along the Kola meridian (33 0 30^fE), alor~ the 43 0 15^fE (north of the Cape Kanin) ¹ betv.reen Kolguyev Islm1.d and south-"tvest part of Novaya Zemlya, bet1'ITeen North Cape a...'1..d Bear Island and v.res t of Bear Island

(71.^to

30

^t

lJ)

and also on other hydrographic sections and at trawl stations, as shovITl in Fig. 1.

A pre1ininary analysis of data made i t possible to conclude the folL:nving (Figs. 2-8):

In early September the temperature of' the 0-200 m layer in the eastern branch of the Spi tsbergen Current in -the section west of' Bear Isla...""1.d .·las only 0.10 higher thru"1. the normal. Compared to the

temperature in 1970, i t was O.L;.o low·er. The temperature of' the 0-200 ^ill layer in the middle branc~ of the Spitsbergen Current in this section -Vlas found to be C1080 to the nor~1al$ but i t was 0.7 0 lmver th.an that of 1970 observed at the same pe:.~iod. The degree of' the surface .varming in. these :laters ","laS si\:1ilar to the long- term mean, but a l i t t l e lower than in 1970~

In early September 1971 the temperature of the 0-200 m layer in the North Cape ·::;-u.rront in the sect=_c:2 north Co..pe-Bear Island vvas found to be tl.1.e .::::.i::.:;hest during all t~"le O-group fish surveys; i t 11"aS 0.6 0 highe:;C' tllan the normal and 0.2 0 higher than that of 19700

At the end of August 1971 tl":w temperature of th.e 0-200 ill layer in the northern branch of the HortI."- Cape Curren.t i~"l the section east-

",ard of Bear Island 1'ITaS found to be close to the norr.lal, but vJaS

0.40 less than in 1970. At 33°JOtE and north of 76⁰ 00^lN the water temperature of this current w'as 0.3 0 be1m;., the normal and 0.7 0 below that of early September 1970.

In late August 1971 the temperatl,1.re of the 0-200 [;1 layer in the Murmansk Current in the section along the 33 0 30^tE was 0.1 0 below

the normal, but

Ot5°

below' that of 1970 observed in the same period. Surface temperature in this current was :foU1~d to be 1.9⁰

below that of' 1970, ,'lhich was characterized by considerable warming up.

- 3 -

At the end of August

1971

in the sec:bi.on north of Cape

Kanin

the temperature of the whole water column in the Hurmansk_Current was found to be close to the normal

and

i t s value in previous years, whereas the surface temperature was

0.7 0

below the normal and

2.60

below that of

1970.

The tomperaturefrom the surface to the bottom in the warm Kanin- 3:01guyev Current w'as aiso cl'idee to the normal ru""1.d i t s va1.ue observed in

1970,

but in the surface layers i t was found to be 1⁰ below

the normal ~~d 2⁰ below that of

1970.

Distribution and abU1~dru""1.ce 9f O-~oup :fish

The variation in tile total density o:f the scattering layers is shown

in Fig. 9.

Tb.e ocho .recordings i.Eclude, as "lell as O-group :fish, contributions :fro:::l fish of' older age-groups, notably capelin, polar cod and blue w22i ting, and also include a:i.'lY echos ~\fihich ;nay cone from invertebrate organisms. The total eCDo abundance has been e.n..'":pressed on a subjective scale :from O_L;-.

In

addition to the species listed below a ^-" JL GTtl 0 vl1.Gr ....

-

species 1-lOre

also recorded in t2~e catches as cnt:fisll₁ lumpsuclrer, .!go~, Leptagonus,

this year.

Percentage length cot:.1posi tioEs of.' the main species caught are given in Fig.

10.

Herring

Ho a-group

-

_{n e} 1.~JL"'l111.b

^.

t:J.is year 8..r..'!.d this is the seventh.

year in succes s ion or very low' n-~'-ll1.dance oX' the species.

Cod

O-group cod "'lOre dis tributed over a ,vide 2 .. :cea ill tl'le central narents Sea :frotTI ITor;;TogiCl.:n. coas t tJ T?o IT ~ "\;Ti t~'l an e::::tension from Bear Islal1.d

11) • Tho area

of' dis-trib-Lltioll vJ8..S S.J~10\·r~_12..t; 10;][3 '3:::tO:1.s"i.-vG tll.a:I:l i.::.1.

1970.

Al thoug:1.

abundru1.t ^Jel2G "1971 3TOCtJ..'" clUSG C2-:1 ~JC descJ.."'ibod ~s bGil1.g of' above average abunda:'1.ce aTlc1 :'loro ni.;l':··lOrous t~1.an Hore record.ed for the year clas s es

T-Iaddoc::.

The distribution of O-group haddocl: 'was similar to that of' cod being distributod over a ,·dde area in the cen.tral Barents Sea ~lith an.

( . 2\

exte:n .. sion l1.0rth1·lurds al.ong the 'west coast of Spitsbergen. F~g. 1 j .

The abunda.r..l.ce of haddock was about average for ti1.e years covered by the International. surveys, the

1971

year class being less abUl1.dm1.t than the

1969

ffi1.d

1970

year classes, but more abundant than the poor year classes of

1965-1968.

- 4 -

Redf'ish.

The O-group redf'ish had a more wGsterly distribution than cod ffiLd haddock an.d the aren. covered was very similar to that observed in

1970,

oovering tb.e vres tern part of' t~1.e Barents Sea Cl.nd extendi:n.g northvmrds along the west coast of' Spitsbergen to

G1

⁰lJ (Fig.

13).

TI1.e

1971

year class appeared to be less abundm1.t thm"l the year classes of'

1970

fu~d

1969.

Capelin

TI1.e abundace of' O-group capelin this year 1,,-as not so great as was observed in the years

1966-1969

t but 'was oore ab"L1.uda...'"1.t than in

1970

which vras reln.tively poor yO:l:;'~. I t should be noted however, that the

1970

year class seeELS to bo 80'.:1G-Vrl"lat stronger than indicated by the las t years O-group fish SU:::"~':'lY:;.r! probably due to a contribution from sumnler spa1·n.1.ed capeli.n.

11Tidespread than in

1970

m1.d more similar to th:t observed in earlier year.s

O-group long rough dn.b were distributed in an area aro~uLd Bear Islm1.d and vrest of Spitsbergen and 0.1:]0 in the eastern Barents Sen. (Fig.

15).

TI:w abundal1.ce lilaS grOQ tOl~ t~1.C:':;':" "in tb.e previous two years, but possibly

not as abundant as in. 196j<-"1967",

There "!ere tvTO are8.:J of dis-tributiol.:" of O-group Polar cod, one in the eastern Barents C,"J?l and the o~::le~~' i:.'l G.:l1. area e:;cJcending froCl Hope Island t

TILe

1971

year class

Greenl~nd halibu~

O-group Gro(m.1Cind 1-:'2libut ",Tore rcc::>:rci.oc~ f'ro,~l eigr_t trawl hauls iIldi- cated in ?ig.

17.

Adul t blue vll:.i ting ";'lere 11ide:"~~ diG t,ri.bu teci O'/Ol~ t~f.O 1'JGS torn part of' the survey area a...1!.d oxtonded e2.S t1rard. to tho regia:;:.]. betlileen Sou t~l Cape Bear Island- Fugle;y.

Additional ~bse~ations

During the COUl-SO of the survoy tl'lore were indications that the small trn.,rl used by llCirolana" .. ,as not catching representative catchos of t!J.e larger O-group :fish, particuln:ry cod mA-d haddocl:. iBarlier this year this net had proved to be very satisfactory :for gadoid fish, but

- 5 -.

during this survey i t "JaS suspected that th0~~adoids, having reachc.d

'--. -

a ~arger siz0, vlGre able to escape capture to sonw--de.gre.o.<-_·-'I'.bis

suspicion was confirmed ,'Vi th comparative hauls vIi th an Engels travll.

During a period of 24 hours fishing by R/V 1!Cirolana !t and R/V !tJohan Ejort" in the ^S2lX:1G position considerable haul,~to haul variation 1,iraS

observed in species composition and the qum~tities of fish caught.

Some evindance was obtained that for redf'ish tue larger fish have a deeper distribution than the smaller ones,

_.'

80'r-~--"G~~;-~Y\---;---~

79'

78'

77'

76'

75'

74'

73'

72'

71' 70' 69'

68 67

5' 10'

Figure 1.

/ /

/

20' 25' 30'

SURVEY ROUTE AND GRID OF STATIONS 20 AUG. - 11 SEP 1971.

35'

o HYDROGRAPHY

• BATHY THERMOGRAPH

" PELAG1C TRAWL o BOTTOM TPAWL

40' 45' 50'

Survey routes and grid of stations.

80'T---~~c_--~----_,r_---~

79' tOe OM

t;, ~

78'

77'

, /

I

76'

75'

6

74'

~7

73'

/8

72'

71'

~

70'

69'

0

68'

,

61'

5' 10' 15' 20' 25' 30' 35' 40' 45' 50'

Figure 2 .. Isotherms at ⁰ m,

Figure

3.

Isotherms at

50

m.

tOe lOOM

4

5" 15" 25" 30" 35"

Figure

4.

Isother ms at 100 m.

..

IJI W 0:: I- W ::E

~ :r l -

w n.

0

80··r---~~~~~---~----~--~---~

100

200

300

400

500

74'30' N 05'14' E

Figure

6.

BEAR ISLAND

3

~

^t'e

Temperature section Bear Island-west.

3-9

September 1971.

."

w 0::

~ w :l:

:!:

:r ~ Q.

W 0

."

W 0::

~ w :l:

:!:

:r ~ Q.

W 0

BEAR ISLAND

200

300

400

500

Figure 7.

100

ZOO

69°30' N 33°30' E

NORTH CAPE

t·e

Temperature section Bear Island-North Cape.

1-3 September 1971.

76°45' N 33°30' E

Figure 8. Temperature in the section along the Kola meridian,

J3030'E. 20 August - 6 September 1971.

80··,---~~----~_r~~---

79'

78'

77'

76'

75'

74'

73'

n'

71'

70' 69'

68'

67"

5' 10'

Figure

9.

,.

2.

,.

2.

'.

2.

,.

2.

,.

2.

,.

2.

,.

20

/\

2. 40

••

Figure 10.

25'

ECHO RECORDINGS 20 AUG. - 11 SE PT. 1971

~ VERY SCATTERED : : : : :: SCATTERED +H+l+It-DEN SE - - - VERY DENSE

.p;j2C'-!\'----=+,--- - - . - - - ... --... .

30' 35' 40' 45'

Courses and echo recordings.

8.

, ..

REDFISH N" 5061

CAPEUN N .. 3026

HADDOCK N·m4

coo

N "4655

POLAR COD N.ZEMlYA AREA N -1652

POLAR COD SPITSBERGEN AREA N"968

LONG ROUGH DAB N-1300

12. aD MM

Length distribution of O-group fish.

50'

80· ~ Cl

" "

"

79·

"

O-GROUP COD

JP:,. " PELAGIC TRAWL

" ^{~ o} BOTTOM TRAWL

78·

"

0>

""

0 ⁶

- "

^M

"

"

⁰

77· ^A

"

"

I ^A

i ^A

"

^{A 0}

"

^{A 1:>0}

"

76· " A

"

_"

"

75· M A

A

"

^~

C- A A A

"

" "

74· " _" " "

"

"

" _"

" "

^{A 8 A}

73· " _{" @} ^A

"

^{4 4}

" ^A

"A

" " ^{A A}

n· " ^{4 A} " ^A

" ^{A A}

71· " ^A

A A

70·

"

_" ^{A A}

A A

69·

68·

67

·5· 10· 15· 20· 25· 30· 35· 40· 45· 50·

Figure 11. Distribution

of

O-group cod.

0

80· ~ ^C7

A

79· _A O-GROUP HADDOCK

JP:,. ^A PELAGIC TRAWL

~

^{~ o} BOTTOM TRAWL

0>

7S· u.

0 AA

A 0

77·

" _I AA

"

A ^A A 0

"

^{A AD. '"}

<- ^A A

"

76·

A

" 0 tAA "

A A

75· _r, ^{A 4 AA 4}

" ~

" ^{c- t.} " " "

74· ^c- A"

" ⁴

" ^~ "

"

" ⁸

" "

"

^{4 " 4 4}

73·

"

⁴

"

" ^{6 4}

"

^{l, 4 l,}

66 f\ ₄ ⁴ <- " 4

'"

n· ⁶

6 6

71· " "

"

70·

t> 4

69· "

68

.

67·

S' 10' 15' 20' 2S' 30' 35' 40' 4S' 50'

Figure 12~ Distribution of' O-group haddock.

79~ a-GROUP REDFISH

Pv ^0. PELAGIC TRAWL

~ o BOTTOM TRAWL

78' a.

""

0 ^t.

""

0. 0

77' .

0. 6

IYJ. 6

" ⁰

"

^" , , 0 0.

6

76' " " 6 6

"

" '" "

75' ^7~' _" 6 " " ^l> 6. t:.Cl. " " " " " "" t:. _'" ⁶ " " " "" ,," _'" " " " '" ^,,6 "" '" 6 " 6 " ⁶ " '" " ^z;

"

6

6 6

'" ⁶ '" "

"

" e "

"

73' " " "

"

^0. " " "

"

" ^c.

"" " " ^£\ " " ^0. " "

72' _0.

"

A ^{0. A} _{" "}

0. " " ^l>

71' ⁶

l>

" ^A

70'

A

69' 68 ,

67' .

5' la' IS' 20' 25' 30' 35' 40' ~5' 50'

Figure

13.

Distribution of O-group redfish.

---,.----

0 ~ ⁰

60'

80' "

"

" " "

" "

79' o - GROUP CAPELlN

" Pv " PELAGIC TRAWL

<- ~ a BOTTOM TRAWL

a.

78' ^A " ^M

0

""

A 0

77'

I ^IYJ. " _" " " ^{0 6 6 0}

"

6 6 6 <-

76'

~ ⁶

751 ^A

"

" ⁶

"~

^{l> 6 A}

73' ⁶

"

l>l> l>

72'

71'

l>

70'

69' 68'

~

67'

5- ID' IS' 20' 25" 3D' 3 S' 40' ~5' 50'

Figure

14.

Distribution of' O-group capeline

80'

79'

'"

78'

77'

75'

75'

74' ^A A

"

73' ^A

l>

AA A

72'

7"

A

70'

69' , 68

r

57'

5' 10'

Figure

15.

80'

A

79' _A

A

78'

77'

A

76'

75'

"

74' ^A A

A

73' ^A

A

A", A

72'

71'

70

1

^h

59'~

68~ ~ 1 1

67~r' I ,

5' 10'

Figure

16.

l>

" " ^{A l>}

" ^{A M}

A £ l>

A

..

^A

A A

i<

AA

A A A

..

A

A ^{A A} A " A A

l> AA

--.-.-r-I I I ^{I I} I ^I

15' 20' 25' 30' 35'

Distribution of' O-group

A

A

""

A

lA", _A

'"

a-GROUP LONG ROUGH DAB

A PELAGIC TRAWL

D BOTTOM TRAWL

"""

D 6

00 D

A D '" ^{A AD}

A A ^M A

" ^A

A

i<

A

A

"

A

<-

"

"

45' 50'

long rough dab.

Cl

A A

A

'"

a-GROUP POLAR COD '" PELAGIC TRAWL

D BOTTOM TRAWL

D

o

Distribution of O-group polar cod.

er.

A

A A

elnqlt-eq

plnque9.I~

dno.x~-o

JO uOllnql.IlS1U eLl.

e.xn~lJI

.os

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.oz

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I

r

9

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69

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