Browsing Brage IMR by Author "Knutsen, Tor"
Now showing items 1-20 of 54
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Acoustic backscatter from zooplankton and fish explored through an optimized model framework
Lebourges-Dhaussy, A.; Knutsen, Tor; Korneliussen, Rolf J. (ICES CM Documents;2004/R:39, Working paper, 2004)The purpose of this work has been to test complementary methods in order to classify marine organisms, with particularly attention to zooplankton and fish. Algorithms to separate fish and zooplankton have been developed ... -
Acoustic manual for the krill synoptic survey in 2019
macaulay, gavin; Skaret, Georg; Knutsen, Tor; Bergstad, Odd Aksel; Krafft, Bjørn Arne (CCAMLR;WG-EMM-18/12, Research report, 2018)The previously presented document at the 2018 ASAM WG meeting (ASAM-18-07) described a design and plans for a synoptic krill acoustic survey in CCAMLR area 48 in 2019. The survey involves the collaborative efforts of Norway, ... -
Acoustic visualization of large scale macroplankton and micronekton distributions across the Norwegian shelf and slope of the Norwegian Sea.
Melle, Webjørn; Kaartvedt, Stein; Knutsen, Tor; Dalpadado, Padmini; Skjoldal, Hein Rune (ICES CM Documents;1993/L:44, Working paper, 1993)We present results from acoustical (38 kHz split beam) surveys, biological sampling (trawling, zooplankton nets), and measurements of physical parameters (salinity, temperature, currents) across and along the shelf ... -
An Antarctic krill (Euphausia superba) hotspot - population characteristics, abundance and vertical structure explored from a krill fishing vessel
Krafft, Bjørn Arne; Skaret, Georg; Knutsen, Tor (Conference object, 2016) -
An Antarctic krill (Euphausia superba) hotspot: population characteristics, abundance and vertical structure explored from a krill fishing vessel
Krafft, Bjørn Arne; Skaret, Georg; Knutsen, Tor (Journal article; Peer reviewed, 2015-06-17) -
Antarctic krill swarm characteristics in the Southeast Atlantic sector of the Southern Ocean
Krafft, Bjørn A.; Skaret, Georg; Knutsen, Tor; Melle, Webjørn; Klevjer, Thor A.; Søiland, Henrik (Journal article; Peer reviewed, 2012-09-28)Knowledge about swarm dynamics and underlying causes is essential to understand the ecology and distribution of Antarctic krill Euphausia superba. We collected acoustic data and key environmental data continuously across ... -
Broadband echo spectra from euphausiids and copepods
Foote, Kenneth G.; Knutsen, Tor; Atkins, Philip R.; Bongiovanni, Claire; Francis, David T. I.; Eriksen, Peter K.; Larsen, Mette Torp; Mortensen, Tom (Others, 2000) -
Climate variations and the state of zooplankton in the Barents Sea
Orlova, Emma L.; Guzenko, V.; Dalpadado, Padmini; Knutsen, Tor; Nesterova, V.N.; Yurko, O. (IMR/PINRO Joint Report Series;5/2007, Conference object, 2007)We present data on zooplankton biomass distribution in August-September 2005-2006 obtained in the integrated ecosystem system survey for the Barents Sea performed by Russian and Norwegian vessels. In order to establish ... -
Climate variations and the state of zooplankton in the Barents Sea
Orlova, Emma L.; Guzenko, V.; Dalpadado, Padmini; Knutsen, Tor; Nesterova, V.N.; Yurko, O. (IMR/PINRO Joint Report Series;5/2007, Conference object, 2007)We present data on zooplankton biomass distribution in August-September 2005-2006 obtained in the integrated ecosystem system survey for the Barents Sea performed by Russian and Norwegian vessels. In order to establish ... -
Climatic variations and the state of zooplankton in the barents sea [presentation]
Orlova, Emma L.; Guzenko, V.; Dalpadado, Padmini; Knutsen, Tor; Nesterova, V.N.; Yurko, O. (IMR/PINRO Joint Report Series;5/2007, Conference object, 2007) -
Climatic variations and the state of zooplankton in the barents sea [presentation]
Orlova, Emma L.; Guzenko, V.; Dalpadado, Padmini; Knutsen, Tor; Nesterova, V.N.; Yurko, O. (IMR/PINRO Joint Report Series;5/2007, Conference object, 2007) -
Coincident mass occurrence of gelatinous zooplankton in Northern Norway
Knutsen, Tor; Hosia, Aino; Falkenhaug, Tone; Skern-Mauritzen, Rasmus; Wiebe, Peter H.; Larsen, Roger B.; Aglen, Asgeir; Berg, Erik (Peer reviewed; Journal article, 2018)In autumn 2015, several sources reported observations of large amounts of gelatinous material in a large north Norwegian fjord system, either caught when trawling for other organisms or fouling fishing gear. The responsible ... -
Detection and counting of individual free-swimming krill using a 2MHz scanning sonar
Ona, Egil; Knutsen, Tor (ICES CM Documents;1992/L:18, Working paper, 1992)The euphausiid crustacean Meganyctiphanes norvegica (M. Sars) have been detected and counted in the scanning section of a 2 MHz scanning sonar beam up to 3 meters from the sonar head. The tests completes a pilot investigation ... -
Distribution and composition of mesopelagic macroplankton and micronekton in the North-east Atlantic
Garcia-Seoane, E.; Klevjer, Thor A.; Knutsen, Tor; Macaulay, Gavin; Mork, Kjell Arne; Rosen, Shale; Strand, Espen; Wienerroither, Rupert; Underwood, Melanie; Melle, Webjørn Raunsgård (Lecture, 2018) -
Ecology of mesozooplankton across four North Atlantic basins
Strand, Espen; Klevjer, Thor A.; Melle, Webjørn Raunsgård; Knutsen, Tor (Peer reviewed; Journal article, 2020)A comparative study of the mesozooplankton in four North Atlantic basins is presented. During a trans-Atlantic expedition with R/V G.O. Sars in May and June 2013, the Norwegian Sea, Iceland Sea, Irminger Sea and Labrador ... -
Ecosystem approach to Barents Sea Ecology : spatial and trophic relationships
Jørgensen, Lis Lindal; Olsen, Erik; Gjøsæter, Harald; Knutsen, Tor; Lønne, Ole Jørgen; Loeng, Harald; Primicerio, Raul (Conference object, 2007-01-22) -
Evidence of diel vertical migration of mesopelagic sound-scattering organisms in the Arctic
Gjøsæter, Harald; Wiebe, Peter H.; Knutsen, Tor; Ingvaldsen, Randi Brunvær (Peer reviewed; Journal article, 2017) -
Experiences in making acoustic measurements in a mesocosm with Calanus finmarchius
Knutsen, Tor; Foote, Kenneth G. (ICES CM Documents;1997/FF:11, Working paper, 1997)In connection with a larger study of the effects of nutrification and turbulence on primary and secondary production, acoustic measurements have been made in the water volume defined by floating, vertically oriented, ... -
Håndbok for prøvetaking og pre-analyse av plankton
Hassel, Arne; Endresen, Berit; Martinussen, Monica; Knutsen, Tor; Johannessen, Magnus E. (Others, 2013-03)Prosedyrer for prøvetaking og pre-analyse av dyre- og planteplankton på forskningsfartøy og i laboratorium på land -
High Latitude Epipelagic and mesopelagic scattering layers-a reference for future Arctic ecosystem change
Knutsen, Tor; Wiebe, Peter H.; Gjøsæter, Harald; Ingvaldsen, Randi Brunvær; Lien, Gunnar (Peer reviewed; Journal article, 2017)