a- FISHERIES AND MARINE SERVICE Translation Series No. 3567 Investigations on the capelin spawning grounds in 1974 It by J. Gjosaeter, K. Hansen, R. Saetre, and T. Westergaard Original title: Undersokelser pa loddas gytefelt i 1974 From: Fiskets Gang 60: 740-744, 1974 Translated by the Translation Bureau(PMJ) Multilingual Services Division Department of the Secre..:ary of State of Canada Department of the Environment Fisheries and Marine Service Biological Station St. John's, Nfld. 1975 9pages typescript
7 DEPARTMENT OF THE SECRETARY OF STATE TRANSLATION BUREAU ' 7 SECRÉTARIAT D'ÉTAT BUREAU DES TRADUCTIONS MULTILINGUAL SERVICES DIVISION CANADA DIVISION DES SERVICES MULTILINGUES TRANSLATED FROM - TRADUCTION DE INTO - EN Norwegian English AUTHOR - AUTEUR J. Gje)saeter, K. Hansen, R. Saetre and T. Westergaard TITLE IN ENGLISH TITRE ANGLAIS Investigations on the capelin spawning grounds in 1974 TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANGÈRE (TRANSCRIRE EN CARACTÈRES ROMAINS) Unders8kelser pa loddas gytefelt i 1974 REFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE FOREIGN CHARACTERS. RÉFÉRENCE EN LANGUE ÉTRANGÈRE (NOM DU LIVRE OU PUBLICATION). AU COMPLET, TRANSCRIRE EN CARACTÈRES ROMAINS. Fiskets Gang REFERENCE IN ENGLISH - RÉFÉRENCE EN ANGLAIS Progress of the fisheries PUBLISHER... ÉDITEUR Norwegian Director of Fisheries PLACE OF PUBLICATION LIEU DE PUBLICATION Bergen YEAR ANNÉE DATE OF PUBLICATION DATE DE PUBLICATION VOLUME 1974 60 ISSUE NO. NUMÉRO PAGE NUMBERS IN ORIGINAL NUMÉROS DES PAGES DANS L'ORI GI NA L 740-744 NUMBER OF TYPED PAGES NOMBRE DE PAGES DACTYLOGRAPHIÉES 9 REQUESTING DEPARTMENT MINISTÈRE-CLIENT Environment TRANSLATION BUREAU NO. NOTRE DOSSIER NO 1101077 BRANCH OR DIVISION DIRECTION OU DIVISION PERSON REQUESTING DEMANDÉ PAR Fisheries Service, Editor Allan T. Reid, Scientific Documentation TRANSLATOR (INITIALS) TRADUCTEUR (INITIALES) PMJ YOUR NUMBER VOTRE DOSSIER NO 1101077 DATE OF REQUEST DATE DE LA DEMANDE 19.09.75 3 052 00.1 0.6 (R E V. 2/88) 7530.21.029-8333
DEPARTMENT OF THE SECRETARY OF STATE TRANSLATION BUREAU SECRÉTARIAT D'ÉTAT BUREAU DES TRADUCTIONS MULTILINGUAL SERVICES DèVISION CANADA DIVISION DES SERVICES MULTILINGUES CLI EN I'S NO. DEPARTMENT DI VISION/BRANCH CI TV N DU CLIENT MINISTE.RE s DIVISION/DIRECTION VILLE Environment Fisheries Service Ottawa, Ont. BUREAU NO. LANGUAGE TRANSLATOR (INI TIALS) N DU BUREAU LANGUE TRADUCTEUR (INITIALES) 1101077 Norwegian PMJ. Investigations on the capelin spawning grounds in 1974 Unders iokelser pa loddas gytefelt i 1974 by J. G,jsaeter, K. Hansen, R. Saetre and T. Westergaard Norwegian Institute for Marine Research, Bergen Fiskets Gang 60: 740-744 (1974) ABSTRACT GJOSeETER, J., HANsEN, K., SiETRE, R. og WEercitoe.Amu, T. 1974. Undersokelser pi loddas gytefelt i 1974. [Investigations at the spawning grounds of capelin in 1974]. Fiskets Gang, 60: 740-744. From 15 March to 6 April the R.V. «Johan Hjort» carried out investigations at the spawning grounds of capelin. The gretest quantities of eggs were found on rather coarse bottom as gravel, shell gravel and pebbles and at depths between 15 and 50 m. No eggs were observed deeper than 120 m. The temperature at the spawning grounds varied between 2.5 C and 3.5 C. Eiders and haddock were observed feeding on capelin eggs. p. 740 Introduction The studies on capelin spawning were this year carried out with R/V "Johan Hjort" in the period March 15 to April 16. was a continuation of the program that was started in 1971. The investigation Earlier results have been published by Dragesund, Gjeisaeter and Monstad (1973); Bjeirke, Gjiisaeter and Saetre (1972); Gjiisaeter, Saetre and Bjeirke (1972); Bakke and Bj&.ke (1973); Gjiisaeter and Saetre (1973). The investigations on the spawning grounds are being followed up with mapping of the larval drift. Data from these studies should give information on the size of the spawning stock along the Norwegian Coast (Gjiisaeter and Saetre 1974). 301-200-1 0-31
2 The following participated from the Norwegian Institute for Marine Research: K. Forberg, T. Fosse, J. GjUaeter, K. Hansen, I. Hoff, E. Klaet, O. Martinsen, R. Saetre, O. Torgersen and T. Westergaard. Materials and Methods In order to localize the spawning grounds and to carry out detailed studies on the grounds chosen, approximately the same instrumentation and methods as described by Bje)rke, Gjàsaeter and Saetre (1972) were used. The quantities of eggs in the grab samples were determined on a subjective scale from 0 to 4. Table 1 indicates the magnitude of the egg densities that corresponds to the various egg quantities. The diving work was carried out by K. Hansen and T. Westergaard. Results The coast of Finnmark was investigated between Sgriiya and Varanger Fjord. The spawning grounds that were located are shown on Fig. 1. The greatest part of the spawning took place inside the crosshatched area on the figure. This year the spawning started in the area Vardg - Kiberg on about March 20. This is about a week later than in 1973. There was no spawning west of Tanafjord this year. The temperatures on the spawning grounds were between 2.5 C and 3.0 C when the spawning started. On the average the temperature was 0.3 C lower than in 1973 during the incubation period; i.e. about the same values as in 1972. Egg Tabell I. Eggtettheter ved forskjellige eggmengder. [Egg den- 1 Densitiesities at different egg quantities].. se Eggmengde Antall egg/m 2 ; 0 Ingen 1 10-1000 2 1000-100000 3 100000 l000000 4 1000000-10000000
3 Fig. 1. Observerte gytefeh. Det dobbeltskraverte feltet representerer hovedgytefeltet. [Observed spawning grounds. The cross hatched area represents the main spawning grounds]. Table 2 shows the distribution of capelin eggs on various bottom materials. As in earlier years the greatest quantities of eggs, quantity 4, were found most often on gravel bottom. Coarse shell sand and shell fragments were this year used less frequently as spawning bottom than in earlier years. Spawning on hard bottom with larger rocks was this year more usual than in earlier years. Fig. 2 shows such a typical hard bottom area. We can see larger and smaller rocks with somewhat finer gravel in between. The spawning had taken place on the gravel, but some eggs were also fastened on larger rocks. The layer of gravel was usually thin and was on top of hard clay. The layer of eggs and bottom material was therefore seldom more than 3 cm thick. p 741
4 'Fig. 2. Typisk hardbunns gytefelt. [Typical spawning area at hard bottom].. _ Gravel Shell sand Mineral sand Hard bottom Clay, mud 1 Tabell 2. Grabbprover. Prosentfordeling av en...e!. 4 0 pà forskjellig substrat. [Grab samples. Percentagc dist -, otition. of egg quantities 0-4 at different su bstrata]... o f puantit yegginengde kggs_l : Ant. No., Substrat of stations I I 1 I 2 I 3. I 4 ; Stasj. ; * Sing el', 56,9 16,5 12,&.5,5 8,3 109' * Skjellsand 81,7 8,8 6,5 2,-f tl.6 169..Nlineralsand 52,9 23,0 18,3 4,6 1,2 87 : Hardbunn 73,5 15,2 5,3 3,7 2,3 487 I:,Leire, mudder 90,9 4,5 4,6 44: 'Total I 71,8 14,4 7,7 3,6 2,5; 896 7
5 Fig. 3 shows in more detail how the eggs can be located on a hard bottom area. The eggs are in layers on the bottom between rocks of various sizes and some empty shells. Concentrations of eggs are often found near the bottom of kelp plants. The eggs are not mixed with the bottom substrate to any extent and stick to each other. ; u ee.. - 11 In areas where the bottom consists of a thicker layer of material with a more homogeneous grainsize such as gravel or coarse shell sand, the eggs tend to be mixed with the bottom substrate to a much greater thickness than is shown on Fig. 3. Figure 4 shows a flat area with gravel having grain sizes from 0.2 cm to 2 cm. On plains of this type one can often observe a wavy texture in the bottom sediments. These waves can be very regular or form a more irregular pattern. The usual dimensions of these waves are; length 1.5-2.0 m and wave height 0.3-0.5 m. These waves have been formed by the current. On the top of the waves
6,.ee '-- rct. " " - ".,.';:- -.,, - - Fig. 4. Bolgestruktur pit en jevn bunn med singel. [Current ripples on a plane gravel bottom]. the material is relatively coarse and few eggs can be found. In the valleys a finer material and many eggs can be found. Due to the concentration of eggs in the valleys between these waves, the valleys appear as lighter colored areas in Fig. 4. These waves will wander and therefore mix together egg and bottom material. The primary reasons for the mixing of bottom substrate and egg that can be observed on some spawning grounds are therefore sediment transport along the bottom caused by currents. Both direct current measurements on the spawning grounds and the capelin's choice of substrate indicate that capelin prefer to spawn in areas with relatively strong currents. The distribution of eggs according to depth can be seen in p 743 Table 3. The greatest concentrations concentrations 3 and 4, were found at depths between 15m and 50m. Eggs were not registered deeper-
7. than 120 m. Last year large concentrations of eggs were found down to ca. 100m. and ege were found all the way down to 280m. Preliminary calculations indicate that the total number of eggs on the spawning ground this year was considerably lower than the numbers estimated for the period 1971 to 1973. also observed. On most localities where diving was carried out, capelin were Fig. 5 shows part of a school of capelin close to the bottom. It appears that the female capelin arrive on the spawning grounds and lay all their eggs at one time and thereafter disappears. The male capelin, however, spend a longer time on the spawning grounds and probably participate in several spawnings. Depth - Tabell 3. Grabbprover. Prosentfordeling av egginengde 0-4. pa forskjellig dyp. [Grab samples. Percentage distribution of egg quantities 0-4 at different depths]. Dyp i m The capelin observed -density Eggmengde 1 Antall JNo. of stations 0 1 I 2 1 3 1 4 1 Stasjoner O-24 51.3 25.7 11.0 5.2 6.3 191 25-49.. 1 68.2 13.8 10.2 5.3 2.5 412 50-74 88.0 9.6 2.4 166.75 99. 1 92.3 6.4 1.3 78 100-124..! 92.3 7.7 96 125-149.. 100.0 17 150-174.. 100.0 4 250-274.... 1100.0 2 Total 71.8 14.4 7.7 3.6 2.5 896 on the spawning grounds were therefore chiefly male capelin. Considerable numbers of dead capelin and "dazed" capelin swimming up in the water in poor physical condition were also observed in the spawning area. Practically all these fish were males. of these capelin in poor condition had a definite "break" in their bodies. It would appear that the spawning had caused several male capelin.to be deformed. Several As in earlier years, haddock could again be observed feeding on the eggs on deeper spawning grounds and diving ducks on shallower grounds. It was obvious that a concentration of diving ducks could be found on the grounds just after spawning had taken place. At one
- 8 '4:''A..1.`'''',.elt. -.-.1 - ^- '?. r :-, kee'._ t - - - :"Z-irkà:ce.--;,3 **7 1. --1; - -, e- s"'" -.- 2. -,. ; e, 24".....: 11,.ner' 7 à L1TTERATUR - - - --,...fy,.,;,;:e.,...-.---.,-.., e'rà e - - - - )! -f.--e''''::"^:,--7.- 1,;;,:e77t3.-.42-,. -1'-età.eil.',,'"..i:' t, ye' 'Se,', _, - e - e,;4e4.1',4-i...$:+-e -_fr rnan'ts.,,w e 2.,'`". *Ce>1" _ - ; e -, e Neet,Z. - Fig. 5. Lodde over g,,tefeltet, hovedsakelig hanloddc. [Capelin at the spawning bed, mainly male capelin].. _ - - - - -- -- of the spawning areas in the Kiberg area,flocks. of 4-5000 ducks, Chiefly eider ducks, were observed. BAKKE, S. and BJORKE, H. 1973. Diving observations on Barents Sea capel in at the spawning grounds off nor thern Norway. Fisk Dir. Skr. Ser. Hay Unders., 16: 140-147. ItORKE, FL, GJOStETER, J. og SiETRE, R., 1972. Undersokelser pà loddas gytefelt 1972. Fiskets Gang, 58: 710-716. DRAGESUND, O., GJOSeETER, J. and MONGSTAD, T. 1973. Estimates of stock size and reproduction of the Barents Sea capelin in 1970-1972. Fisk Dir. Skr. Ser. Hat; tinders., 16: 105-139. - - Literature... _. Bjôrke, H., Gjiisaeter, J. and Saetre, R. 1972. p 744 OrSeETER, J., SiETRE, R. cg 13JORKE, H. 1972. Dykkende beiter pà loddeegga. Sterna, 11: 173-176. og SJETRE, R. 1973. Unclersokelser pà locldas gytefelt 1973. Fiskets Gang, 59: -715-748. and S.ETRE, R. 1974. The use of data on eggs and larvae for estimating 'spawning stock of fish populations with demersal eggs. P. 139-149 in BLAXTER, J. H. S. cd. The early life history of fish. Springer-Verlag, Berlin. Investigations on the capelin spawning grounds 1972. Fiskets Gang. 58: 710-716. " -
Gjeisaeter, J., Saetre, R. and Bjdrke, H. 1972. Diving ducks feed on capelin eggs. Sterna, 11: 173-176. GS$Ssaeter, J., and Saetre, R. 1973. Investigations on the capelin spawning grounds 1973. Fiskets Gang. 59: 745-748.