Browsing Brage IMR by Author "Fernö, Anders"
Now showing items 21-40 of 44
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How and why acoustic detectability and catchability of herring change with individual motivation and physiological state in a variable environment: a multi-scale study on a local herring population in southwestern Norway
Langård, Lise; Nøttestad, Leif; Johannessen, Arne; Fernö, Anders; Øvredal, Jan Tore; Skaret, Georg; Nilsson, Gro N.; Vabø, Rune (ICES CM documents, Working paper, 2006)The understanding of distribution and aggregation in herring (Clupea harengus) can be enhanced by integrated multi-scale studies in small ecosystems. Hydro-acoustics, underwater cameras, herring and predator gillnet samples ... -
Impact of herring spawning behaviour on acoustic abundance estimates
Skaret, Georg; Fernö, Anders; Nøttestad, Leif; Johannessen, Arne; Axelsen, Bjørn Erik (ICES CM documents, Working paper, 2001)Spawning dynamics of Norwegian spring spawning herring was studied in south western Norway 29 March to 3 April 2000 using hydroacoustics. The horizontal distribution of the spawning layers shifted in a south-easterly ... -
Learning and anticipatory behaviour in a “sit-and-wait” predator: the Atlantic halibut
Nilsson, Jonatan; Kristiansen, Tore S.; Fosseidengen, Jan Erik; Stien, Lars Helge; Fernö, Anders; van den Bos, Ruud (Journal article; Peer reviewed, 2010-03)We studied the learning capacities and anticipatory behaviour in a “sit-and-wait” predatory fish, the Atlantic halibut, Hippoglossus hippoglossus. In Experiment 1 two groups of halibut received series of light flashes ... -
Learning and anticipatory behaviour in a “sit-and-wait” predator: the Atlantic halibut
Nilsson, Jonatan; Kristiansen, Tore S.; Fosseidengen, Jan Erik; Stien, Lars Helge; Fernö, Anders; van den Bos, Ruud (Journal article; Peer reviewed, 2010-03)We studied the learning capacities and anticipatory behaviour in a “sit-and-wait” predatory fish, the Atlantic halibut, Hippoglossus hippoglossus. In Experiment 1 two groups of halibut received series of light flashes ... -
Mating competition between farmed and wild cod Gadus morhua
Skjæraasen, Jon Egil; Meager, Justin J.; Karlsen, Ørjan; Mayer, Ian; Dahle, Geir; Rudolfsen, Geir; Fernö, Anders (Journal article; Peer reviewed, 2010-08-18)Increasing numbers of hatchery-produced fish entering marine environments has caused concern over potential fitness depressions in wild populations, yet no study has addressed the likelihood of hybridisation between farmed ... -
Migration behaviour of herring along the cold front in the Norwegian Sea in April 1997
Misund, Ole Arve; Fernö, Anders; Guenette, Sylvie; Mackinson, Steven; Melle, Webjørn; Nøttestad, Leif; Slotte, Aril (ICES CM Documents;1997/EE:12, Working paper, 1997)The behaviour of Norwegian spring spawning herring when migrating to the feeding areas in the Norwegian Sea in April was mapped by an acoustic survey in 1997. The distribution of herring was recorded by conventional echo ... -
Migration behaviour of Norwegian spring spawning herring when entering the cold front in the Norwegian Sea
Misund, Ole Arve; Melle, Webjørn; Fernö, Anders (ICES CM Documents;1996/H:13, Working paper, 1996)The distribution of Norwegian spring spawning herring when migrating to the feeding areas in the Norwegian Sea in spring has been mapped by surveys in April1995 and 1996. The schooling behaviour of the herring have been ... -
Migration patterns in Norwegian spring-spawning herring: why young fish swim away from the wintering area in late summer
Kvamme, Cecilie; Nøttestad, Leif; Fernö, Anders; Misund, Ole Arve; Dommasnes, Are; Axelsen, Bjørn Erik; Dalpadado, Padmini; Melle, Webjørn (Journal article; Peer reviewed, 2003-03-04)Norwegian spring-spawning herring Clupea harengus make extensive feeding migrations in the Norwegian Sea during summer. At the end of the feeding season herring may meet conflicting demands between moving to areas with ... -
Numerical domination and herring migrations
Huse, Geir; Fernö, Anders; Holst, Jens Christian (ICES CM documents, Working paper, 2006)There is accumulating evidence in favour of the hypothesis that herring migrations are influenced by social learning. The “adopted-migrant hypothesis” postulates that recruit spawning herring learn migration patterns by ... -
Preliminary studies on the influence of bottom obstructions and topography on the availability of demersal fish for gillnet fishing in the North Sea.
Valdemarsen, John Willy; Fernö, Anders (ICES CM Documents;1979/B:21, Working paper, 1979)Gillnet fishing experiments were carried out in the Little Fisher Bank area in the North Sea. Saithe and pollack and to some extent cod showed a patchy distribution along a gillnet string. The abundance of fish was ... -
Prey selection of offshore killer whales Orcinus orca in the Northeast Atlantic in late summer: spatial associations with mackerel
Nøttestad, Leif; Sivle, Lise Doksæter; Krafft, Bjørn A.; Langård, Lise; Anthonypillai, Valantine; Bernasconi, Matteo; Langøy, Herdis; Fernö, Anders (Journal article; Peer reviewed, 2014-03-03)The traditional perception of prey species preference of killer whales Orcinus orca L. in the Northeast Atlantic has, to a large extent, been linked to herring Clupea harengus L. Few studies have investigated the feeding ... -
Recent changes in distribution and relative abundance of cetaceans in the Norwegian Sea and their relationship with potential prey
Nøttestad, Leif; Krafft, Bjørn Arne; Anthonypillai, Valentine; Bernasconi, Matteo; Langård, Lise; Mørk, Herdis Langøy; Fernö, Anders (Journal article; Peer reviewed, 2015) -
Red King Crab: Vertical movements of crabs trapped in the odour plume explain differences in catch efficiency between square and conical pots
Stiansen, Stian; Fernö, Anders; Furevik, Dag M.; Jørgensen, Terje; Løkkeborg, Svein; Godøy, Hallvard (Conference object, 2006-10) -
A sonar study of the migration pattern of Norwegian spring-spawning herring (Clupea harengus L.) in July
Kvamme, Cecilie; Nøttestad, Leif; Fernö, Anders; Misund, Ole Arve; Dommasnes, Are; Axelsen, Bjørn Erik (ICES CM documents, Working paper, 2000)About 700 schools of Norwegian spring-spawning herring (Clupea harengus L.) were tracked by multi-beam sonar during transect surveys in the Norwegian Sea in July 1995 and 1996. This herring stock usually concentrates in ... -
Spatial and temporal overlap and trophic interactions between Atlantic Saithe (Pollachius virens) and Norwegian spring spawning herring (Clupea harengus) on herring spawning grounds
Slotte, Aril; Runde, Arne; Skaret, Georg; Axelsen, Bjørn Erik; Fernö, Anders; Johannessen, Arne; Nøttestad, Leif; Øvredal, Jan Tore (ICES CM documents, Working paper, 2005)Atlantic saithe (Pollachius virens) and Norwegian spring-spawning herring (Clupea harengus) represent two of the most abundant and ecologically important fish species in the Northeast Atlantic. The two species co-occur ... -
Studies on the behaviour of some gadoid species in relation to traps
Valdemarsen, John Willy; Fernö, Anders; Johannessen, Arne (ICES CM Documents;1977/B:42, Working paper, 1977) -
Surface activity of Atlantic salmon (Salmo salar) in net pens
Furevik, Dag M.; Huse, Ingvar; Bjordal, Åsmund; Fernö, Anders (ICES CM Documents;1988/F:19, Working paper, 1988)An important feature of the behaviour of salmon is the leaping and rolling activity. These surface activities were studied in fish in net pens in relation to environmental factors and operational procedures. Data were ... -
The challenge of the herring in the Norwegian Sea: making optimal collective spatial decision
Fernö, Anders; Melle, Webjørn; Misund, Ole Arve; Pitcher, Tony; Nøttestad, Leif; Mackinson, Steven; Hollingworth, Charles (ICES CM Documents;1996/H:15, Working paper, 1996)Herring are long-lived multiple spawners exhibiting strong variation in reproductive and recruitment success between years. They tend to adopt low-risk, preferred-conservative strategies; for example, shifts to alternative ... -
The dynamics of a metapopulation: changes in life-history traits in resident herring that co-occur with Oceanic herring during spawning
Johannessen, Arne; Skaret, Georg; Langård, Lise; Slotte, Aril; Husebø, Åse; Fernö, Anders (Journal article; Peer reviewed, 2014-07-22)Different populations of Atlantic herring are regarded as forming a metapopulation, but we know little about the dynamics of the connectivity and degree of interbreeding between the populations. Based on data from three ... -
The effect of shading in pen rearing of Atlantic salmon (Salmo salar)
Huse, Ingvar; Bjordal, Åsmund; Fernö, Anders; Furevik, Dag M. (ICES CM Documents;1988/F:18, Working paper, 1988)A full scale pen rearing experiment with covers to reduce illumination was carried out. No significant effects were observed on growth, mortality, ectoparasite infection, maturation or net pen fouling.