Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Nøttestad, Leif"
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Await in the pelagic: herring compromising reproduction and survival within a vertically split school
Axelsen, Bjørn Erik; Misund, Ole Arve; Fernö, Anders; Nøttestad, Leif; Johannessen, Arne (ICES CM documents, Working paper, 1998) -
Distribution and behavioural dynamics of ocean feeding Norwegian spring spawning herring: observations across spatio-temporal scales
Misund, Ole Arve; Nøttestad, Leif; Mackinson, Steven; Guenette, Sylvie; Pitcher, Tony; Fernö, Anders (ICES CM documents, Working paper, 1998) -
Extensive gas bubble release in Norwegian spring spawning herring (Clupea harengus) during predator avoidance
Nøttestad, Leif (ICES CM Documents;1998/J:20, Working paper, 1998)Events of extensive gas bubble releases in overwintering Norwegian spring spawning herring (Clupea harengus) were repeatedly observed acoustically and visually in Vestfjorden, northem Norway, during attacks from killer ... -
Feeding ecology of Atlantic mackerel (Scomber scombrus) in the Norwegian Sea
Langøy, Herdis; Nøttestad, Leif; Skaret, Georg; Broms, Cecilie; Fernö, Anders (ICES CM documents, Working paper, 2006)Previous studies on Atlantic mackerel (Scomber scombrus) feeding during the highly migratory summer period are scarce. In this study we present detailed diet analyses and investigations of prey selection for Atlantic ... -
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 ... -
Influence of sea temperature on herring distribution and migration in the Norwegian Sea in April 1997
Nøttestad, Leif; Misund, Ole Arve; Orvik, Kjell Arild; Ulvestad, Bente Hoddevik (ICES CM Documents;1999/M:3, Working paper, 1999)After spawning at the west coast of Norway, the Norwegian spring spawning herring migrates northwestwards into the Norwegian Sea to feed in early April. The herring enters areas with distinct oceanographic features both ... -
Killer whales (Orcinus orca L.) and saithe (Pollachius virens L.) trap herring (Clupea harengus L.) in shallow water by taking advantage of steep bottom topography
Nøttestad, Leif (ICES CM Documents;2002/N:20, Working paper, 2002)Whales and fish use a wide range of hunting tactics in order to catch their prey. Predatorprey interactions have been seen during the massive wintering of herring (Clupea harengus) in steep bottomed topography in Lofoten, ... -
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 ... -
Snake pipefish (Entelurus aequoreus) intrusion as a new species into the Barents Sea ecosystem.
Reeve, Magnus; Olsen, Erik; Nøttestad, Leif (ICES CM documents;2007/H:04, Working paper, 2007)The snake pipefish Entelurus aequoreus is a member of the Syngnathidae family. The open water species is distributed in the eastern Atlantic, from the Azores to Iceland and Norway, including the Baltic Sea. Concentrations ... -
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 ... -
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 ...