Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Jørstad, Knut Eirik"
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A genetic marker for artificially reared cod (Gadus morhua L.)
Jørstad, Knut Eirik; Øiestad, Victor; Paulsen, Ole Ingar; Naas, Kjell Emil; Skaala, Øystein (ICES CM Documents;1987/F:22, Working paper, 1987)Artificially reared cod at the Aquaculture Station Austevoll on the west coast of Norway, were screened for genetic markers by using biopsies of white muscle, individual tags and enzyme genotype as determined by starch ... -
A method of observing the spawning behaviour of farmed and wild salmonids in a natural stream habitat
Skaala, Øystein; Jørstad, Knut Eirik; Fernö, Anders (ICES CM Documents;1993/M:21, Working paper, 1993)When farmed fish escape from farms, they may compete with wild individuals for a number of resources, such as food, spawning sites, and mates. As a part of a larger study on genetic impact from farmed fish on wild ... -
Americans on the wrong side – the lobster Homarus americanus captured in Norwegian waters
van der Meeren, Gro; Ekeli, Kees O.; Jørstad, Knut Eirik; Tveite, Stein (ICES CM documents, Working paper, 2000)In November 1999, two female lobsters, one with external egg batch, were captured in the common lobster fishery in the Oslo fjord, Norway and reported as possible American lobsters, Homarus americanus, to Bergen Aquarium ... -
Coastal releases of Atlantic salmon, a new model for salmon ranching in Norway
Holm, Marianne; Jørstad, Knut Eirik; Skilbrei, Ove; Pedersen, Tom N.; Skaala, Øystein; Nortvedt, Ragnar (ICES CM Documents;1991/M:38, Working paper, 1991)The present project is launched within the frame of a 7 year government funded programme to establish an additional livelihood for the coastal regions. The aim of the study is, through controlled experiments, to find ... -
Comparative growth and survival of two genetic strains of Atlantic cod (Gadus morhua L.) reared through the early life stages in a marine pond in western Norway
Blom, Geir; Svåsand, Terje; Jørstad, Knut Eirik; Otterå, Håkon; Paulsen, Ole Ingar; Holm, Jens Christian (ICES CM Documents;1990/F:48, Working paper, 1990)The investigation was carried out in a marine pond in western Norway during spring and summer 1990. Two genetic defined strains of Atlantic cod (Gadus morhua L.) were used as broodstocks. A total of 11.1 x 10^6 cod larvae ... -
Discrimnation of herring populations in a northern Norwegian fjord: genetic and biological aspects
Jørstad, Knut Eirik; Pedersen, S.A. (ICES CM Documents;1986/H:63, Working paper, 1986)From a trawl survey in a fjord system in northern Norway, it has been possible to separate catches of herring into two distinct groups characterized by different number of vertebrae (VS). Low- vertebral herring (VS = ... -
Enzyme polymorphism expressed in newly hatched cod larvae and genetic analysis of larvae exposed to hydrocarbons.
Jørstad, Knut Eirik; Solberg, Tor Sverre; Tilseth, Snorre (ICES CM Documents;1980/F:22, Working paper, 1980)Cod eggs and larvae, at different stage of development, have been analyzed by starch gel electrophoresis. Four common enzymes (phosphoglucose isomerase, phosphoglucose mutase, isocitrate dehydrogenase and lactate ... -
Enzyme polymorphism of sprat from Norwegian waters - preliminary results
Jørstad, Knut Eirik; Nævdal, Gunnar (ICES CM Documents;1981/H:65, Working paper, 1981) -
Genetic assignment as a tool to identify the origin for Atlantic cod (Gadus morhua) escapees in Norwegian fjords
Dahle, Geir; Jørstad, Knut Eirik; Johansen, Torild; Westgaard, Jon-Ivar; Knutsen, Halvor; Glover, Kevin A. (ICES CM documents;2009/Q:14, Working paper, 2009) -
Genetic comparison of salmon (Salmo salar L.) from the White Sea and the Atlantic ocean
Skaala, Øystein; Makhrov, Alexander; Karlsen, Tove; Jørstad, Knut Eirik; Altukhov, Yuri Petrovich; Politov, Dmitri V.; Kuzishin, Kirill V.; Novikov, Georgii Gennadievich (ICES CM Documents;1996/M:13, Working paper, 1996)Samples of salmon (Salmo salar) from River Kachkovka and R. Nilma in northem Russia were analysed by starch gel electrophoresis and compared to three Norwegian stocks, R. Neiden in northern Norway and R. Øyre and R. Hop ... -
Genetic studies on released and recaptured cod in a fjord system
Jørstad, Knut Eirik; Nævdal, Gunnar (ICES CM Documents;1992/G:65, Working paper, 1992)The study reported here is part of a more extensive investigation on the effects of mass rearing and release of 0-group cod in fjords and coastal areas in Norway. Each year since 1987 pond produced cod have been liberated ... -
Migratory behaviour of cultured Atlantic salmon smolts released during day or night
Holm, Marianne; Huse, Ingvar; Jørstad, Knut Eirik; Ona, Egil; Skilbrei, Ove (ICES CM documents, Working paper, 1998) -
Population genetic structure of wrasses used as cleanerfish in Atlantic salmon farming in Norway
Sundt, Rolf C.; Jørstad, Knut Eirik (ICES CM Documents;1993/G:30, Working paper, 1993)The increasing use of wrasses as cleaner fish in the salmon farming industry has created local fishery in many regions in Norway. In several cases, live fish have been transported between regions without knowledge of the ... -
Recruitment of wild and artificially reared cod (Gadus morhua L.) to the local spawning stock
Svåsand, Terje; Jørstad, Knut Eirik; Kristiansen, Tore S. (ICES CM Documents;1987/F:27, Working paper, 1987)A stock enhancement study of coastal cod was initiated in 1983, when 19,002 artificially reared cod fry were tagged and released in the Austevoll region in western Norway. As a part of this program, 3,946 cod fry were ... -
Screening for genetic markers to assess potential genetic impact from salmon ranching on wild stocks
Skaala, Øystein; Dahle, Geir; Taggart, John B.; Jørstad, Knut Eirik; Unneland, Laila; Karlsen, Tove; Bakke, Gunnar; Paulsen, Ole Ingar (ICES CM Documents;1991/M:14, Working paper, 1991)Genetic markers are needed to assess the potential genetic impact on wild salmon populations from ocean ranching. In 1990 spawners from four Norwegian rivers: Lone, Vosso, Dale and Onarheim were screened for genetic ... -
Significance of population genetics on management of herring stocks.
Jørstad, Knut Eirik; Nævdal, Gunnar (ICES CM Documents;1981/H:64, Working paper, 1981) -
Significance of population genetics on management of herring stocks.
Jørstad, Knut Eirik; Nævdal, Gunnar (ICES CM Documents;1981/H:64, Working paper, 1981) -
Studies on associations between genotypes and growth rate of 0-group cod
Jørstad, Knut Eirik; Nævdal, Gunnar (ICES CM Documents;1992/G:66, Working paper, 1992)The aim of the present study was to investigate genotype dependent growth rate in young cod. The material of 0-group cod was collected from pond produced cod in western and northern Norway, and analysed for genotype ... -
Studies on environmental conditions and influence on salmon farm production
Ervik, Arne; Jørstad, Knut Eirik; Farestveit, Eva; Wennevik, Vidar; Eriksen, Anne Grete; Lerøy, Rita (ICES CM Documents;1990/F:35, Working paper, 1990)The study was undertaken to investigate how environmental conditions influence growth of Atlantic salmon, and how different sub groups of salmon respond to different environment. The fish were raised at five different ... -
The use of genetic tagging to study interaction between farmed and wild atlantic cod stocks
Jørstad, Knut Eirik; van der Meeren, Terje; Dahle, Geir; Paulsen, Ole Ingar; Svåsand, Terje; Otterå, Håkon (ICES CM documents;2009/Q:12, Working paper, 2009)Escapement of farmed fish from the aquaculture is considered as a risk for negative genetic impacts on native gene pools. In order to investigate potential interbreeding between cultured and wild Atlantic cod, Gadus ...