Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Røttingen, Ingolf"
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The language of fishery management advice offered by ICES
Sandberg, Per; Røttingen, Ingolf; Gjøsæter, Harald (ICES CM documents, Working paper, 2003)Since the establishment of the Exclusive Economic Zones in the mid 1970s, several exploited fish stocks in the Northeast Atlantic have been managed by total allowable catch (TAC). The advice on annual levels of TAC, as ... -
Management Strategies for Northeast Arctic Saithe: - should predation on herring be taken into account?
Mehl, Sigbjørn; Røttingen, Ingolf; Sandberg, Per (Working paper, 2006)The Norwegian Directorate of Fisheries has suggested a management strategy for Northeast Arctic saithe. Based on the assumption that a maximum sustainable yield is achieved at a fishing mortality below Fpa, a strategy ... -
Measurements of the density coefficient and average target strength of herring using purse seine.
Hagström, Olle; Røttingen, Ingolf (ICES CM Documents;1982/B:33, Working paper, 1982)Integrator values were obtained from a school of herring. The fish density of this school was determined on the basis of a purse seine catch. From these values a conversion factor and average target strength for herring ... -
Norwegian investigations in 1984 -1985 on juvenile herring
Røttingen, Ingolf (ICES CM Documents;1985/H:53, Working paper, 1985)This paper describes tlte Norwegian investigations on juvenile herring (0-, I- and II-group) of the Norwegian spring spawning stock. The investigations were carried out in Norwegian coastal areas and in the Barents Sea ... -
Norwegian spring spawning herring (Clupea harengus L.): protection of spawning areas in relation to changes in migration pattern
Røttingen, Ingolf; Slotte, Aril (ICES CM documents, Working paper, 1998) -
Potential sources of unaccounted mortality in the fishery for Norwegian spring spawning herring
Røttingen, Ingolf; Sandberg, Per; Schultz, Bjarne; Slotte, Aril (ICES CM documents, Working paper, 2002)The stock of Norwegian spring spawning herring (NSSH) is managed and fished by 5 different parties. These are the EU, Faroe Islands, Iceland, Norway and Russia. The most common gears are purse seine and pelagic trawl. The ... -
Reappearance of Norwegian spring spawning herring on spawning grounds south of 60°N
Røttingen, Ingolf (ICES CM Documents;1989/H:22, Working paper, 1989)In spring 1989 herring spawned west of Karmøy (near Haugesund) on the Norwegian west coast. Prior to 1945 the coastal areas around Haugesund were among the most important spawning (and fishing) grounds of the Norwegian ... -
Recent migration routes of Norwegian spring spawning herring
Røttingen, Ingolf (ICES CM Documents;1992/H:18, Working paper, 1992)The migration routes of Norwegian spring spawning herring have changed considerably during the last decades. In the 1950s and beginning of the 1960s the stock spawned off the west coast of Norway in late winter, were ... -
Reduced oxygen concentrations in herring wintering areas
Dommasnes, Are; Rey, Francisco; Røttingen, Ingolf (ICES CM Documents;1992/H:16, Working paper, 1992)Since 1987 the major part of the adult Norwegian spring spawning herring stock has been wintering in the Ofotfjord and the Tysfjord, two tributaries to the Vestfjord in northern Norway. The herring enter the fjords in ... -
Repeated acoustic surveys on small herring in a fjord area
Ona, Egil; Røttingen, Ingolf (ICES CM Documents;1986/H:70, Working paper, 1986)This paper describes an acoustic survey on small herring in a fjord in Northern Norway which was carried out three times during the same night. The survey speed was 4 knots during two of the survey runs and once 8 ... -
Report of the Planning Group on Surveys on Pelagic Fish in the Norwegian Sea [Bergen, Norway, 28- 30 August, 2002]
Jacobsen, Jan Arge; Gudmundsdottir, Asta; Heino, Mikko; Holst, Jens Christian; Krysov, Alexander; Melle, Webjørn; Mork, Kjell Arne; Røttingen, Ingolf; Tangen, Øyvind; Vilhjálmsson, Hjálmar (ICES CM Documents;2002/D:7, Working paper, 2002) -
Return of Norwegian spring spawning herring (Clupea harengus L.) to historical spawning grounds off southwestern Norway
Bergstad, Odd Aksel; Røttingen, Ingolf; Toresen, Reidar; Johannessen, Arne; Dragesund, Olav (ICES CM Documents;1991/H:24, Working paper, 1991)From the mid-1940s to mid-1960s a northward displacement of the spawning areas of the Norwegian Spring Spawning Herring was observed. Further retraction of the population from traditional feeding and spawning grounds ... -
Studies of minke whale (Balaenoptera acutorostrata) ecology in the northeast Atlantic: Description of the 1993 scientific catch operations and preliminary results from stomach analyses and resource surveys
Haug, Tore; Lindstrøm, Ulf; Nilssen, Kjell Tormod; Røttingen, Ingolf (ICES CM Documents;1994/N:14, Working paper, 1994)Ecological studies of the Northeast Atlantic minke whale (Balaenoptera acutorostrata), initiated in 1992, were continued in 1993. The field work was carried out in spring (15 April-15 May), summer (15 June-12 July) and ... -
Swimming speed of spent Norwegian spring spawning herring
Røttingen, Ingolf; Røttingen, Jostein (ICES CM Documents;1991/H:9, Working paper, 1991)In March 1990 spent Norwegian spring spawning herring were tagged on the spawning grounds off Karmøy in southwestern Norway. 37 of these tagged herring were recaptured approximately 40 hours later. The recapture took place ... -
Target strength measurements and acoustic biomass estimation of capelin and 0-group fish
Dalen, John; Raknes, Askjell; Røttingen, Ingolf (ICES CM documents, Working paper, 1976) -
The choice of TAC when faced with multiple objectives
Sandberg, Per; Bogstad, Bjarte; Røttingen, Ingolf; Veim, Anne Kjos (ICES CM Documents;1996/P:15, Working paper, 1996)The total allowable catch is a key instrument in fishery management, and advice on its level used to be based purely on biology. In 1991, ACFM stated that its objective was to provide the advice necessary to maintain ... -
The herring fishery
Hamre, Johannes; Røttingen, Ingolf (ICES CM Documents;1988/H:58, Working paper, 1988) -
The Norwegian spring-spawning herring prior to 1970 [Life history]
Hamre, Johannes; Røttingen, Ingolf (ICES CM Documents;1988/H:56, Working paper, 1988) -
Towards an MSY-based management of Barents Sea capelin in an ecosystem context
Røttingen, Ingolf; Tjelmeland, Sigurd (ICES CM documents;2009/R:07, Working paper, 2009) -
The use of Medium-Term Forecasts in advice and management decisions for the stock of Norwegian spring spawning herring (Clupea harengus L.)
Bogstad, Bjarte; Røttingen, Ingolf; Sandberg, Per; Tjelmeland, Sigurd (ICES CM documents, Working paper, 2000)Medium-term simulations on the stock development of Norwegian spring-spawning herring (Clupea harengus L.) have been carried out since 1994 by the ICES «Atlanto-Scandian Herring and Capelin Working Group», in 1996 renamed ...