A technique for sectioning blue whiting otoliths for age determination

The basic principle of the method is to embedd the otoliths in a two component glue whereafter it is sectioned with a jewelers saw. When using this method a trained technician can section and make age determinations of approximately 50 otoliths per day

Investigations on capelin and sand eel at West-Greenland in June - July 1974

The investigations was carried out with M/S «Havdrøn» as an acoustic survey of the banks and a few selected fjords from Arsukfjord (N 61°1O´, W 78°30´) to Umanakfjord (N 71°00´, W 52°OO´). The capelin stock had recently spawned when the survey started, and during the first part of the cruise capelin, apart from some small concentrations on Fyllasbank, were only found in inshore areas and fjords. Later a migration to the banks took place, and during the last part of the cruise capelin were found on all the southern banks. Samples of the capelin indicated that only the largest immature 2 and 3 years old capelin and capelin surviving the spawning had so far migrated to the banks. While most of the stock was found in inshore areas, no attempt was made to calculate the stock size of capelin of West-Greenland. It is, however, tentatively concluded that the stock size is 5 - 10 %, compared to the capelin stock in the Barents Sea. Shoals of sand eels were registered on all the banks surveyed at West-Greenland. The burrowing habits of sand eel prevents any acoustic estimation of these species, and only relative echo abundances are given. The catches consisted of mostly old fish, 6 years and older. Spawning had only commenced the southernmost banks

Blue whiting surveys in the Norwegian Sea in April - May 1971

On a cruise with R.V."G.O.Sars" from 24 April to 9 May dense concentrations of blue whiting were found between the Faroes and Shetland and in the Norwegian Deep east of Tampen. Further north the fish were scattered. A preliminary estimate of the blue whiting population within the area covered, was about 2 • 10/10 fish. The dense concentrations of blue whiting between the Faroes and Shetland were on a later cruise from 28 May to 31 May found further north and northwest. A comparison of the maturity stages of the fish caught in the different areas indicated that this movement was a migration from the spawning area

Blue whiting surveys in the Norwegian Sea in April-May 1971

On a cruise with R/V "G. O. Sars" from 24 April to 9 May dense concentrations of blue whiting were found between the Faroes and Shetland and in the Norwegian Deep east of Tampen. Further north the fish were scattered. A preliminary estimate of the blue whiting population within the area covered, was about 2 * 10^10 fish. The dense concentrations of blue whiting between the Faroes and Shetland were on a later cruise from 28 May to 31 May found further north and northwest. A comparison of the maturity stages of the fish caught in the different areas indicated that this movement was a migration from the spawning area

Blue whiting surveys northwest of the British Isles in February - March 1972

On a cruise with the R.V. «G. 0. Sars» from 28 February to 26 March 1972 the distribution and abundance of blue whiting northeast of the British Isles were observed by direct hydroacoustic methods. The stock size was estimated to about 5 x lO(10 fish or 10 mill. tons. The fish were in prespawning state and located in warm saline Atlantic water at depths varying between 350 and 550 metres forming either shoals or layers of thicknes from 30 to 50 metres

Capelin investigations in the Barents Sea in November-December 1971

Relative echo abundance of capelin is given. Mainly young immature capelin was found in the area Thompson Ground - Southern part of the Sentral Bank. The population in the area between the Sentral Bank and the Skolpen Bank was dominated by older maturing specimens. Of the maturing specimens in the catches 14 % was from the 1969 year-class, 66 % from the 1968 year-class and 20 % from the 1967 year-class. The distribution of capelin showed a relation to the hydrographic situation, with recordings in the front areas. Compared to the distribution found on a similar survey in September, part of the capelin population had migrated south in the cold water towards the Skolpen Bank. The survey was limited northwards by the ice border, and it is tentatively concluded that only about 50 % of the population was distributed outside the ice covered area

Blue whiting investigations in the Norwegian Sea and northwest of the British Isles in January - February 1973

Blue whiting investigations were carried out at the Møre— Helgeland plateau and in the Faero—Shetland areas during the period 8 January to 9 February. Most of the blue whiting were localized in the Faero— Shetland area. The best consentrations were found in the transition layers between the Atlantic water masses and the colder masses below and beside. The fish was here in a prespawning state and was probably mowing towards the spawning locality. An acoustic abundance estimate of the recorded blue whiting in this area gave a total 15 x 10\6 hl

Report on blue whiting fishing experiments west of The British Isles in February-May 1973

The experiments were carried out with four boats. Two of a different size working as one boat midwater trawlers and two as a twoboat midwater trawl unit. It is concluded that the spawning stock is dense enough for commercial fishing during March-April with the gear used, but that prospects for a profitable fishery is best for the larger one-boat midwater trawler

Detection of internally tagged fish with special application to the atlanto-scandian herring

The paper describes the operating principle and use of a new machine for detection and sorting of internally tagged fish. The machine has been used in the calculation of the Atlanto-Scandian herring stock size. Fixed installations at major fish landing sites with a more advanced sorting machine are planned

Kolmuleundersøkelser i Norskehavet i april-mai 1971

On a cruise with R/V "G. O. Sars" from 24 April to 9 May dense concentrations of blue whiting were found between the Faroes and Shetland and in the Norwegian Deep east of Tampen. Further north the fish were scattered. A preliminary estimate of the blue whiting population within the area covered, was about 2 * 10^10 fish. The dense concentrations of blue whiting between the Faroes and Shetland were on a later cruise from 28 May to 31 May found further north and northwest. A comparison of the maturity stages of the fish caught in the different areas indicated that this movement was a migration from the spawning area