CM_1980_G53.pdf (891.6Kb)

Thispapernot tobecitedwithoutpriorreferencetotheauthors International Council for CM 1980/G :53

the Exploration of the Sea Demersal Fish Committee Ref : Pelagic Fish and Hydrographic Committees

Preliminary report of the International 0-group fish survey in the Barents Sea and _adjacent_waters in

-Auqust___September_1980 The sixteenth annual International 0-group fish survey was made

during the period 16 August - 8 September 1980 in the Barents Sea and adjacent waters . The following research vessels partici- pated in the survey :

State Name of vessel Survey time Research Institute Norway "Johan Hjort" 16 August 7 September Institute of Marine

Research, Bergen Norway "G .O . Sars" 16 August 7 September ^{if It} "

Norway "Michael Sars" 16 August 8 September ^{if If} "

USSR "Poisk" 22 August 8 September The Polar Research Institute of Marine Fisheries and Oceano- graphy, Murmansk

USSR "Achil" 2 S pt mb r 4 S pt mb r 11 "

Nam o sci ntists and t chnicians who took part on th di r nt v ss ls ar giv n in th App ndix .

Th surv y data was analys d th 8-9 S pt mb r in Hamm r st . Obs rvations conc rning th g ographical distribution o 0-

group ish and th ir abundanc ar giv n in this r port tog th r with a bri discription o th t mp ratur condition in th

ar a .

MATERIAL AND METHODS

Th g ographical distributions o 0-group ish hav in arli r surv ys b n stimat d by ishing with a small m sh d midwat r trawl at th d pth o h avi st trac s o 0-group ish on th

chosound r, mainly b tw n 0-50 m . At stations with no r cordings o 0-group ish th trawl was tow d in th sur ac or 1 nautical

2

mil . Wh n som 0-group was r cord d th trawl was tow d in two st ps, in th sur ac and at a d pth o 25 m, 0 .5 nautical mil in ach d pth . A high r standardiz d trawling proc dur would b pr rabl . How v r, th trawling t chnic has mad this di icult .

For ishing in th n ar sur ac lay r, loats hav to b us d on th h adlin o th trawl . By trawling d p r than 20 m a d pth m t ring d vic has to b us d or accurat control o th d pth o trawling . Som trawling xp rim nts in th b gin- ning o th surv y show d that it is possibl to control th trawling d pth with both loats and a d pth m t ring d vic on th trawl . This mak it possibl to cov r th wat r column rom 0-80 m in on haul . Th Norw gian v ss ls which us trawls with a 20 m v rtical op ning cov r this wat r column by trawling with th h adlin in 0, 20, 40 and 60 m in succ ssion .

An xamination o cho r cordings rom arli r surv ys indicat s that 0-group ish is obs rv d only a w tim s d p r than 40- 50 m . It would th r or b su ici nt to mak only on haul at

ach station with th Norw gian typ o midwat r trawl to cov r th 0-group ish lay r .

A t r th 28 August th d scrib d trawling proc dur was ollow d by th Norw gian v ss ls on most o th ir trawl stations, and th trawling distanc was 0 .5 nautical mil at ach o th

d pth ; 0, 20 and 40 m . Th USSR v ss l which us d a trawl with a 6 m v rtical and 10 m horizontal op ning op rat d th trawl according to th old proc dur . Each v ss l mad on trawl haul about v ry 30 nautical mil sail d .

Th participants in th Hamm r st m ting discuss d th n d or a urth r standardization o trawl g ars and trawling proc dur . Th y agr d to r comm nd that :

1 . all v ss ls participating in th 0-group surv y should us th sam typ o midwat r trawl as th Norw gian v ss ls and it should b rigg d as n ar as possibl in th sam way .

- 3 -

2 . at ach station th trawl should b tow d 0 .5 nautical mil at ach o th d pth ; 0, 20 and 40 m, i n c ssary also at 60 m .

Surv y tracks and hydrographical stations ar giv n in Fig . 1 . Trawl stations with and without catch ar giv n on th distri- bution charts in Figs . 10-17, as ill d and op n symbols r sp c- tiv ly . Th d nsity grading is bas d on catch in numb r p r 1 .0 nautical mil trawling .

RESULTS

Hydrography (Figs . 2-9, Tabl s 1-4)

Hydrographic obs rvations w r mad along all th surv y tracks, normally a t r ach 30 nautical mil sail d . Horizontal t mp ra- tur distributions ar shown or 0, 50, 100 and 200 m d pth

(Figs . 2-5) . Figs . 6-9 show th t mp ratur conditions at our standard s ctions, and th m an t mp ratur o th s s ctions ar giv n in Tabl s 1-4 . Som g n ral comm nts ar giv n b low : 1) Kola s ction

During th last two y ars th m an t mp ratur in this s ction has b n low, but th 1980 valu s ar now clos to th av rag or 1965-80 in all thr lay rs .

2) Cap Kanin - North s ction

Th m an t mp ratur in this s ction was in 1980 high r than in th pr vious y ars 1978 and 1979, but it is still b low th av rag valu or 1965-80 . Th anomali s ar -0 .3 ° C in th north rn part and -0 .8 ° C in th south rn part o

th s ction .

3) North Cap - B ar Island s ction

Th m an t mp ratur in th s ction has gradually incr as d sinc 1977, th cold st y ar at th p riod 1965-80 . Th

1980 valu is 0 .1 ° C abov th av rag 1965-80 .

4

4) B ar Island - W st s ction

Th m an t mp ratur o th 0 - 200 m lay r was this y ar 0 .6 ° C abov th av rag valu or th p riod 1965-80 . Th 1980 is th r or r gard d as a rath r varm y ar and similar to th conditions ound during 1973 and 1976-77 . In g n ral, th 1980-t mp ratur s o th w st rn Bar nts S a ar about normal, wh r as th ast rn part o th s a is still som what cold r than th av rag 1965-80 . Th t mp ratur

conditions w st o th B ar Island indicat a rath r strong transport in th Spitsb rg n curr nt .

DISTRIBUTION AND ABUNDANCE OF 0-GROUP FISH

G ographical distribution o 0-group ish ar shown by shad d ar as in Figs . 10-17. . Doubl shading indicat s d ns conc ntra- tions . Crit ria us d to discriminat b tw n scatt r d and

d ns cons ntrations ar th sam as us d in arli r r ports (Ann .biol . 1978) .

Abundanc indic s stimat d as th ar a o distribution, ar as o high d nsiti s w ight d by 10, ar giv n in Tabl 5 . L ngth

r qu ncy distributions o th main sp ci s ar giv n in Fig . 18 .

H rring (Fig . 10)

0-group h rring was ound in w numb rs and only on 14 trawl stations, mainly o th East Finnmark coast . Th abundanc o th 0-group h rring is still low in th ar a cov r d by th surv y .

Cap lin (Fig . 11)

Th distribution o 0-group cap lin in 1980 is similar to that ound in 1979 . Th high st conc ntrations w r ound o th Finnmark and th Murman coast .

Contrary to th oth r sp ci s d scrib d in th pr s nt r port, 0-group cap lin is mostly ound ntangl d in th m sh s in th

middl part o th trawl . This mak s it di icult to sampl 0- group cap lin unbias d rom y ar to y ar particulary b caus o variabl w ath r conditions . An abundanc ind x or cap lin ?s th r or assum d to b o littl valu . How v r, Fig . 11 giv s th impr ssion that th 1980 y ar class is an abundant on .

Cod (Fig . 12)

0-group cod was ound in two main ar as o th coast o Finnmark and w st o Spitsb rg n . It is th ourth y ar in succ ssion a w st rly distribution o 0-group cod has b n obs rv d .

Th ar a o distribution was ound to b rath r small, and no d ns cons ntrations w r obs rv d . Th stimat d abundanc

ind x o th 1980 y arclass is about hal o that or 1979, and is only 21% o th av rag 0-group ind x or th pr vious 10 y ars .

Haddock (Fig . 13)

0-group haddock has in 1980 a w st rly distribution, and is similar to that ound in 1978 . No high conc ntrations w r

ound . Th abundanc ind x is only about hal o th av rag abundanc ind x in th pr vious 10 y ars .

Saith

Only a w numb rs o 0-group saith w r caught . As in pr vious y ars no abundanc ind x o any signi icans can b stimat d on th basis o th surv y data .

Polar cod (Fig . 14)

Th distribution o 0-group polar cod was similar to thos ound in th pr c ding thr y ars, with a Spitsb rg n and a

Novaya Z mlja compon nt . As in last y ars th ar a o distribution was not ad quat ly cov r d b caus o limit d r s arch v ss l

tim . Th stimat d abundanc indic s ar th r or too low or both compon nts .

5

R d ish (Fig . 15)

0-group r d ish was ound within a larg ar a rom Lo ot n to th Murman coast, and continuously b tw n Norway and th

north rn part o Spitsb rg n . Th abundanc ind x indicat that th 1980 y ar class is n arly as strong as th 1979 y ar class . Gr nland halibut (Fig . 16)

As in pr vious y ars 0-group Gr nland halibut was mostly ound o B ar Island and Spitsb rg n . Th abundanc ind x or th 1980 y ar class is clos to th av rag abundanc ind x rom 1970 to 1979 .

Long rough dab (Fig . 17)

As in th last y ars, xc pt or 1979, 0-group long rough dab was common in th trawlcatch s in th ar a w st o Spitsb rg n .

Compar d with 1979 it was also ound urth r to th ast in th Bar nts S a . Th abundanc ind x is abov th av rag in th pr vious 10 y ars .

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Fig . 17 . Distribution o 0-group long rough dab .

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Tabl2.ManwatrtmpraturinthCapKanin-Northsction (btwn68°45'Nand72°00'N)romsurac

Tablawatrtrn:praturinthMurmanskcurrnt,thKolasction (btwn70030'Nand690301N) atthandoAugust(t°C). Avrag Yar19651966196719681969197019711972197319741975197619771978197919801965-1980 Layr 0-50m6.76.77.56.46.77.87.18.77.78.17.08.16.96.66.57.47.2 50-200m3.82.64.03.73.13.63.24.04.53.94.64.03.42.52.93.53.6 0-200m4.63.64.94.44.04.74.25.25.54.95.25.04.33.63.84.54.5 tobottomatthbginningoSptmbr(t°C). "Yar1965196619671968196919701971197219731974197519761977197819791980Avrag 1965-1980 170°05'N 700 051N4.82.06.14.72.64.04.05.15.74.65.64.94.12.42.03.34.1 71°°00'N .4.22.53.63.12.33.33.24.14.54.34.63.31.71.83.03.3 7200' N, Tabl3. Man watr tmpraturin thNorth Capcurrnt,thNorth Capto Bar Island sction (btwn 71°33', 25°02!E and 73°35'N, 20°46'E) at thnd oAugust and at thbginning oSptmbr (t°C). Avrag Yar19651966196719681969197019711972197319741975197619771978197919801965-1980 Layr 0-200 m5.15.55.65.46.06.15.76.35.96.15.75.74.85.05.35.75.6

T

abl

i an wat r tamparatur in t° W st Spitsb rg n cur-rant slor th S ar l .and W st sactiors ia tws n 06 0 34 1 E and 15 0 55° E) in arly S pt mb r (t o C) . Av rag Y ar 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1966-1980

0-200m 3 .3 4 .2 3 .6 4 .2 4 .2 3 .9 5 .0 4 .6 4 .9 5 .0 4 .0 4, .1 4 .4 4,9 4 .3

Sp ci s

Gr nland

1965 6 7 0 159 66 1966 1 . 1 129 236 97 1967 34 42 165 44 73 1968 25 8 60 21 17 1969 93 82 208 295 26 1970 606 115 197 247 <1 12 1971 157 73 181 172 <1 81 1972 140 46 140 177 8 .0 65 1973 684 54 (26) 385 3 .2 67 1974 51 147 227 468 13 .4 83 1975 343 170 75 315 21 .1 113 1976 43 112 131 447 15 .6 96 1977 173 116 157 70 472 9 .0 72 1978 106 61 107 144 460 35 .4 76 1979 94 69 23 302 980 22 .5 69 1980 49 54 79 247 651 12 .0 108

I In N 1

APPENDIX 16AugustSptmbr"G.O. Sars" 16August- 7Sptmbr"Johan Hjort"InstitutoMarinRsarch,C.Aranda,J.Blindhim,K.A.Larsn Brgn0.Martinsn,C.J.Rorvik,J.Rorvik J.Sortland,A. Thomassn, 0.Torgrsn.

Brgn InstitutoMarinRsarch; Brgn

T.Monstad,J.H.Nilsn,T.H.Sancjol S.Torhim. G.Farstad,K.Gjrtsn,K.Hansn, A.Hyln,H.Kismul,E.Lijsll, L.Midttun,E.Molvwr,K.Randa, I.Svllingn,0.Tangn.

SurvypriodRsarchvsslRsarchInstitutParticipants 22August- 8 Sptmbr"Poisk"PolarRsarchInstitutoA.V.Avrchnko,V.D.Boitsov, MarinFishrisandOcano-O.J.Gavrilina,A.U.Iljina, graphy,MurmanskU.N. Kochdykov,L.N.Korol', U.S. Mamylov, V.N. Nnko, N.G.Ushako V.P. Vorontsov. 2 Sptmbr - 4 Sptmbr"Akhil"Polar Rsarch Instituto MarinFishris and Ocano- graphy, Murmansk 16 August - 8 Sptmbr"Michal Sars"InstitutoMarinRsarch, S. Brattas, R. Johannssn, J.Monsta