Hydrografiske undersøkelser og kartlegging av fiskefordeling i Nordsjøen i februar 1972

The present report outlines the results of a survey carried out by R. V. "G. O. Sars" and R. V. "Johan Hjort" in February 1972. The distribution and relative abundance of fish in the North Sea were mapped on the basis of echo integrator readings. Samples obtained by mid water and bottom trawls supported the identification of echo recordings and provided material for biological analyses of dominating fish species. The general features of the hydrography was determined, and the distribution of air and sea temperatures, temperature anomalies, and salinities are presented. Significant differences in echo integrator readings were observed: between day and night, between the two ships and in relation to obtained catch. Bottom trawl catches varied between 45 and 1545 kg per hour. Best catches were taken in the southeastern part of the North Sea. In total, herring, whiting and haddock amounted to 26, 25 and 21 per sent respectively while Norway pout, flatfish and other species each were less than 10 per cent in weight. Distribution, size, age etc. are reported in detail for the dominating species, and the relationship between the distribution and the abiotic environment is discussed, Young herring were found in greatest concentrations in the Bløden area. Sprat were found in the coastal waters, characterized by relatively low salinity, while Norway pout were most numerous in Atlantic water in the northern part on the North Sea plateau. Blue whiting and coalfish were mainly observed along the western slope of the Norwegian trench below the core of the Atlantic water which penetrates into the North Sea

Fish survey west of the British Isles in October 1970

Områdene sør av Irland er kjente gytefelt for makrell og sild. Disse fiskestammers utbredelse og livsmønster med hensyn til eventuell utnyttelse av norske fiskere er lite kjent. Den norske ringnotflåten som opererte i området rundt Shetland sist sommer, var i kontakt med forekomster av makrell som ikke tilhørte makrellstammen i Nordsjøen. Disse forekomstene var delvis oppblandet med stor taggmakrell som er vanlig å finne i området vest av Irland. Dette kan således indikere hvilket område disse blandete forekomstene stammer fra. Ved Hebridene finnes det videre en høstgytende sildestamme som delvis har vært beskattet av den norske ringnotflåten i Shetlandsområdet i sommerhalvåret. I tiden 4.—20. oktober ble det med F/F «G. O. Sars» foretatt en undersøkelse av området vest av De Britiske Øyer. Hensikten var å undersøke muligheten for utnyttelse av de makrell- og sildeforekomster som måtte finnes i området på denne årstid og å undersøke hvorvidt det fantes andre fiskearter som kunne danne grunnlag for kommersiell drift. Det avsøkte området fremgår av Fig, 1. Den tekniske stab på roktet besto av O.Chruickshank, P, Eide, H. Gill, J. Klæt, W. Løtvedt, S. Myklevoll, og A. Storler. «G. O. Sars» ble ført av A. Lunde

On the life history of the spotted catfish (Anarhichas minor Olafsen)

Spotted catfish, Anarhichas minor Olafsen, were sampled from long line and trawl catches taken along the coast of Finnmark, near Bear Island and in the Barents Sea in 1953 and 1954. Age was determined from vertebraes. Fish younger than 6 years were not found in the long line samples. The age groups 12-14 were most abundant in the long line samples taken off Finnmark as against 8-9 years old fish dominating the samples taken near Bear Island. The females were found to attain sexual maturity at an age of 6-7 years and a length of about 75 cm and the males approximately one year later at a length of 80-85 cm. The present study indicates that the spotted catfish spawn in July-August. In 1953, 1954 and 1955 a total of 432 catfish were tagged with Lea Hydrostatic tag. Until January 1963 71 were recaptured. The seasonal distribution and migration of the catfish are discussed

The migration of norwegian herring to icelandic waters and the environmental conditions in may-june, 1961-1964

The present material on zooplankton, temperature and herring have been collected in the Norwegian Sea, from the Faroes along the east and north-east coast of Iceland to Jan Mayen as a part of the Norwegian herring investigations, in collaboration with Iceland and U.S.S.R. during May and June 1961-1964. Zooplankton was collected in vertical hauls from 50 m to the surface with a Juday net (1961-62) and a Hensen net (1963-64). Temperature was measured at standard depths from surface to 500 m. A termograph measured the surface temperature (at 4 m) throughout the cruises. Herring were located by horizontal and vertical accoustic fish detection devices (sonar, echo sounders). The herring have been observed migrating across the East Icelandic Current east or north-east of Langanes in waters below 3°C. The distribution and migrations of herring in relation to temperature, plankton biomass (ml/m³) and the distribution of the copepodite stages of Calanus finmarchicus are discussed

On the identification of recruit spawners in the Norwegian herring stock

Herring Committee

Comparison Between Catch per Unit Effort in the Norwegian Gill-net and Purse-seine Fishery for Herring

Symposium on the Measurements of Abundance of Fish Stock