Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Knutsen, Tor"
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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 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 ... -
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 ... -
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, ... -
Initial collateral measurements of some properties of Calanus finmarchicus
Dalpadado, Padmini; Foote, Kenneth G.; Knutsen, Tor; Bækkevold, Anna Ersland; Johannessen, Signe E. (ICES CM Documents;1996/L:21, Working paper, 1996)In general, acoustic quantification of zooplankton such as Calanus finmarchicus requires the use of models, among other reasons, to aid in the interpretations of data collected on animals whose scattering properties change ... -
Mapping of marine data
Westgård, Trond; Knutsen, Tor (ICES CM Documents;1988/C:39, Working paper, 1988)In the last 7-8 years the Institute of Marine Research has developed and exchanged computer routines with other research institutes, building up effcient tools for computer presentation of marine data. The routines are ... -
Preliminary report from the sea-going workshop in Norway June 1993 on intercomparison and evaluation of methods for sampling and determination of zooplankton distribution and biomass
Skjoldal, Hein Rune; Wiebe, Peter H.; Knutsen, Tor; Postel, Lutz (ICES CM Documents;1993/L:45, Working paper, 1993)A sea-going workshop was arranged from 2 to 13 June 1993 in Storfjorden at Møre on the west coast of Norway. The workshop was a two-ship operation involving the Norwegian R/V "Johan Hjort" and the German R/V "A.V. Humboldt". ... -
Underwater optics and behavioral responses of krill to presence of fish predators affect fish-plankton interactions
Kaartvedt, Stein; Skjoldal, Hein Rune; Melle, Webjørn; Knutsen, Tor (ICES CM Documents;1993/L:43, Working paper, 1993)In clear oceanic waters off the Norwegian shelf and in outer shelf waters, mesopelagic fish (Maurolicus muelleri) were located at approximately 200 m by day. Across a front into water of lower light penetration, M. ...