P R E F A C E

The main task of editing papers from a Symposium is to ensure that they are published as soon as possible after the meeting. However, the conclusions and recommendations of this Symposium highlight the lack of knowledge of some potentially valuable fish. Because of this, im portant data have been added to some papers during editing, and several verbal reports to the meeting have been included in this volume at the request of the Symposium. Thanks to the willing cooperation of the authors the am endm ents and editing have not unduly delayed its preparation for publi­cation.

The terms of reference excluded consideration of the herring, redfish and some other pelagic species which are already exploited wherever they occur. The

original title also did not include the words “ and adjacent seas” bu t as m any of the papers deal with species which do not occur in Arctic waters, the addition of a few words to the title seems more desirable than deletion of a num ber of papers.

For the sake of uniformity, wherever possible the scientific names used are those published in ICES Bulletin Statistique, Vol. 49 for 1964 (Copenhagen 1966).

I would like to thank Dr. E .M . P o u l s e n for his help and advice both a t the meeting and during the editing of this volume, and M r. R . J . W o o d and others who have helped in sorting out the discussion notes. Finally, Miss R o s e B e d f o r d and her assistants of the Fisheries Laboratory must also be thanked for checking the typescripts and proofs.

R. W. BlackerEditor and Rapporteur

I N T R O D U C T I O N

At the Statutory M eeting of the International Council for the Exploration of the Sea in 1963 the Distant N orthern Seas Committee and the Gadoid Fish Committee presented to the Council recommen­dations that a Symposium be organised on the “ Ecology of Pelagic Fish Species in Arctic W aters” . These recommendations were renewed in 1964, and Dr. E r i k M. P o u l s e n was nom inated Convenor of the Symposium. A Steering Committee including the Convenor and the Chairm en prepared a program m e for the Symposium in which the m ain lines of the Symposium were designed as follows

(a) The significance of the pelagic fish within the food-chains in the Arctic and the role of these species as food for the most im portant commer­cial fishes,

(b) M igration and distribution of the pelagic fish in Arctic waters and their relationship with distribution and movements of the m ain commer­cial fishes,

(c) The biological basis for fishery of pelagic fish in the Arctic.

In the 1965 Statutory M eeting the Distant N orthern Seas Committee prepared a Preliminary Programme for the Symposium.

The Recommendations on the Symposium were adopted by the Consultative Committee and the Council, and the Symposium was convened on September 30th and October 1st, 1966, a t Charlotten- lund Castle in connection with the Statutory Meeting of tha t year.

M r. R. W. B l a c k e r was asked to act as R apporteur, and he accepted this task.

Thirty-eight experts from m em ber countries, from C anada and USA as well as from international organisations connected with fisheries and m arine researches participated in the Symposium.

Twenty-one papers had been submitted and during the Symposium four additional contributions were given verbatim, these latter are also included in the present publication of the contributions.

Furtherm ore, two synopses, one on Norway pout and the other on poutassou prepared for FAO by M r. D. F. S. R a i t t were submitted to the Symposium for comments. These two synopses were considered and comments on them were given. The Symposium expressed the wish tha t the preparation of these highly useful synopses be continued by FAO to include also other fish species of commercial interest in the Arctic and in adjacent regions.

T he scientific papers for the Symposium were considered (reviewed by authors or other experts) in the following order in accordance with the Agenda: 1 - General (occurrence), 2 - Capelin, 3 - greater silver smelt, 4 - smelt, 5 - Norway pout, 6 - Blue whiting, 7 - Polar cod, 8 - Navaga, and 9 - General (food interrelations).

After each of these items a consideration and discus­sion of the pertinent papers took place.

Thereafter followed a general discussion of the main subject, as follows :—

1. The species as links in food-chains; discussion- leader: D. V. R a d a k o v , U S S R .

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S E C T IO N 1: General Distribution

1. T H E D I S T R I B U T I O N O F P E L A G I C F I S H I N R E L A T I O N T O H Y D R O G R A P H I C

C O N D I T I O N S I N T H E SV A L B A R D A R E A

By

R .W . B l a c k e r

Fisheries Laboratory, Lowestoft

IN T R O D U C T IO N

D uring the course of English investigations into the biology of the cod in the Svalbard area, the R .V . “ Ernest H olt” was fishing there regularly from 1949 to 1959 with some additional cruises during 1960 to 1964. Records of fish other than the commercial species are available from most of these cruises, and a num ber of pelagic or bathypelagic species were recorded. Most of these were caught in the cod-end or in a fine-meshed cod-end cover on a standard G ranton bottom trawl, bu t occasional hauls were also m ade with pelagic trawls. Some small fish were caught in plankton nets, and the routine examination of the stomach contents of cod gave further information on the occurrence of some species.

T H E FISH

T he following pelagic species were recorded from the area north of 70°N latitude:

Mallotus villosus (Müller), Capelin.Argentina silus (Ascanius), G reater Silver Smelt, Argen­

tine.Paralepis rissoi kroyeri Lütken, ( = Notolepis r.k. (Lütken)). Myctophum glaciale (R einhard t).Notoscopelus elongatus (Costa).Trisopterus esmarkii (Nilsson), Norway pout.Merlangius merlangus (L.), Whiting.Gadiculus argenteus thori, Schmidt.Eleginus navaga (Pallas), Navaga.Boreogadus saida (Lepechin), Polar cod.Micromesistius poutassou (Risso), Poutassou, Blue W hit­

ing.

Herring, Saithe and Sebastes spp. were caught frequently bu t do not come within the scope of this Symposium. The “ Ernest H o lt’s” records of

Argentina silus are included in the paper by R a i t t and W o o d (this meeting) and those of Mallotus villosus in a paper by C o r l e t t (this meeting), so no further reference will be m ade to them. Details of the records of the less common of the other pelagic species are given in Table 1:1. B. saida and M . poutassou were caught on too m any occasions for all the data to be tabulated.

H Y D R O G R A PH Y

The basic current system of the area is well known ( L e e 1952) and need not be shown here. Briefly, the hydrographic system is a balance between the Atlantic influence of the West Spitsbergen and N orth Cape currents and the Arctic influence of the Bear Island and East Spitsbergen currents.

D IS T R IB U T IO N O F T H E FISH

The two most common pelagic fish, AI. poutassou and B. saida, both of which have been caught in quantities of up to 38 kg per hour, provide a striking contrast in their distributions: B. saida is an Arctic species and M . poutassou an Atlantic one. All the “ Ernest H olt” records of the two species are plotted in Figure 1:1. The hatching indicates the area of predom inating Atlantic influence as shown by the distribution of benthic indicator species ( B l a c k e r ,

1957 and 1965). T he correlation between the distri­bution of the records of M . poutassou and this Atlantic area is clear. Likewise most of the records of Myctophum glaciale and those of Notoscopelus elongatus, Paralepis, Merlangius and Trisopterus esmarkii are also from this Atlantic area (Figure 1:2), bu t in contrast there are few records there of B. saida. In fact there are only two from near Bear Island and some from West Spitsbergen, where there m ay be wide variations in the hydrographic conditions.

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Table 1:1.

Occurrences o f the rarer pelagic species

Cruise and station Date

Position Lat. N Long. E

O f O /Depth

(m)Tem peratSurface

ure (°C) Bottom

Totalnum bercaught

Remarks

1. Trisopterus esmarkii (Nilsson)

6/1951 31 25 October 74 45 18 30 187 0-8 4-52 185 31 76 36 14 12 190 5-3 4-57 1

3/1955 23 23 April 74 16 16 22 313 4-6 1-94 21/1957 11 7 M arch 69 45 16 53 274 - - s/4 basket

80 17 72 30 15 40 453 5-6 - 185 18 70 29 17 46 274 - - l*/s basket included spawning females88 18 70 26 17 08 302 _ - 1289 18 70 31 17 08 348 - - 5990 18 70 26 17 40 165 - - 1/2 basket91 19 71 36 17 40 292 - - 1

100 24 70 03 17 06 156 - - 113101 24 70 02 17 03 183 - - 48103 26 68 04 11 46 161 - - 8

2. Merlangius merlangus (L.)

1956 December 73 40 19 05 ? - - 1 S. T. Grimsby Town1/1957 11 7 M arch 69 45 16 53 274 - - 2

101 24 - 70 02 17 03 183 - - 1

3. Gadiculus argenteus thori Schmidt

1/1957 11 7 M arch 69 45 16 53 274 - _ 191 19 - 71 36 17 40 292 - - 25 10-4 to 17-0 cm

4. Eleginus navaga (Pallas)

6/1961 60 25 August 75 12 33 35 238 6,2 1-06 I 25 cm

5. Notoscopelus elongatus (Costa)

2/1954 51 24 M arch 72 31 22 40 340 5-4 4-34 1

6. Myctophum glaciale (Reinhardt)

3/1950 ? M arch ? ? ? ? 2 in cod stomach8/1950 88 10 October 74 21 17 04 201 6-7 3-58 1 _2/1951 20 28 M arch 73 50 18 44 241 - 2-40 3

32 30 - 70 31 14 06 2830 - - 15 2 m larvae net4/1951 36 19 Ju n e 75 20 33 32 165 2-0 -0 -4 6 12/1952 41 15 M arch 73 49 19 12 240 3-4 1-98 1 in cod stomach4/1953 64 29 M ay 74 25 12 34 2270 3-7 - 1 in plankton net (Sta. W)6/1953 21 24 August 76 48 29 02 212 4-5 - +

91 9 September 74 25 13 00 2340 7-9 - 1 in plankton net (Sta. W)7/1953 49 19 October 75 53 34 22 241 3-0 -0 .4 1 26/1955 81 17 September 79 05 07 48 1100 6-0 - 1 in plankton net1/1956 83 25 Jan u a ry 70 18 32 29 177 3-4 3-56 16/1956 35 23 September 74 25 15 30 1540 6-5 - 3 in plankton net (Sta. V)2/1957 107 18 M ay 74 54 31 53 286 3-0 1-24 1 in fish gut

7. Paralepis rissoi kroyeri Lütken

5/1950 48 31 M ay 73 561/2 17 30 243 5-6 2-67 1 in cod stomach2/1951 12 26 M arch 74 12 22 56 183 - 1-62 1 _2/1952 67 18 - 74 301/» 22 07 201 2-3 0-46 +4/1953 39 24 M ay 74 26 24 42 283 2-4 - 1

56 27 - 74 25 25 42 - 2-2 - 18/1953 19 28 November 73 46 31 50 329 5-3 3-12 14/1954 70 24 Ju n e 74 06 27 02 406 5’6 2-20 12

71 24 - 74 02 26 45 411 5-6 _ 472 24 - 73 57 26 26 421 - _ 4

6/1958 30 15 October 79 33 09 28 213 2-6 3-34 17/1959 47 12 79 09 08 36 302 2-4 3-26 1

9

a M. pou tassou

■ T. esm ark ii

o B saida

navaga

Figure 1:1. Records of pelagic gadoids caught by the R. V. “ Er­nest H olt” , 1949-1964.

Figure 1:2. Records of rare pelagic and bathypelagic fish caught by the R. V. “ Ernest H olt” , 1949-1964.

20"

30*

Para lep is k ro y e r i r ' C.

M yc to p h u m glaciale J

N o to sco p e lu s (e lo n g a tu s

Eleginus navaga is the only other Arctic species, but the single record from the Central Bank (75°12'N, 33°35'E) is exceptional in tha t the norm al distri­bution of E. navaga is in shallow w ater in the SE Barents Sea, from the coast of east M urm an and the W hite Sea eastwards to the G ulf of O b, with occasional specimens as far west as the Kola In let ( A n d r i y a s h e v

1954).T he northernm ost and north-easternmost occur­

rences of the Atlantic species are for the summer and au tum n months, when the penetration of surface A tlantic w ater is a t its maximum. Although the catches of the pelagic fish are probably not quan tita ­tive, there is some indication that the greatest numbers

of such species as Paralepis have occurred in years when there has been a great influx of Atlantic water into European seas ( D i c k s o n , personal com m uni­cation). The small numbers of myctophids from all sources indicate tha t they must be m uch less numerous in the north-east Arctic than they are in Greenland waters, where they constitute an im portant part of the food of cod and other commercial species.

r e f e r e n c e s

A ndriyashev, A. P., 1954. “ Fishes of the northern seas of the U S SR ” . Keys to the Fauna of the USSR, No. 53. Academy of Sciences of the USSR. Moscow-Leningrad. (Israel Program for Scientific Translations N° 836, Jerusalem, 1964).

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B la c k e r, R. W., 1957. “Benthic animals as indicators of hydro- graphic conditions and climatic change in Svalbard waters” . Fishery Invest., Lond., Ser. II , 20: (10), 49 pp.

B l ac ker, R. W., 1965. “ Recent changes in the benthos of the

West Spitsbergen fishing grounds” . Spec. Publ. int. Commn NW Atlant. Fish., (6) 791-794. Dartm outh, N.S.

L ee , A. J . , 1952. “ The influence of hydrography on the Bear Island cod fishery” . Rapp. P.v. Réun. Cons. perm. int. Explor. Mer, 131: 74-102.

2. D I S C U S S I O N

T he au thor pointed out tha t his list om itted some species, notably Ammodytes spp, and Cyclopterus which are pelagic a t times. H a n s e n stated tha t sand eels are im portan t off West G reenland from Disko southwards where they often occur in the surface waters and in summer are im portant as food of cod, redfish, halibut and salmon. They also cccur in grab samples taken in the fjords. O n the east and south of the Newfound­land G rand Bank sand eels are also im portant as the food of o ther species, according to T e m p l e m a n .

K r e f f t confirmed tha t Notoscopelus, Lampanyctus and other myctophids are im portant food species off East G reenland and in the D enm ark Strait. Scopelosaurus, Bathylagids, Searsids and other Isospondylous fishes

m ay also be im portant there. Paralepis coregonoides is im portant as food of cod off Labrador. N i k o l s k y

said tha t off the Asian coast, the Pacific cod feeds on myctophids.

B l a c k e r mentioned tha t on several occasions re ­cently Cyclopterus lumpus had been caught in pelagic trawls off West Spitsbergen. H o r s t e d and V i l -

h j ä l m s s o n agreed tha t a t G reenland and Iceland lumpsuckers were also pelagic for part of the year.

N i k o l s k y stressed tha t future work should include the collection of data on the relative im portance of myctophids and other bathypelagic species in the diet of commercial fishes.