Blar i ICES CM documents authored by IMR scientists (1949-2011) på emneord "VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924"

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    • Acoustic sampling volume for cod 

      Foote, Kenneth G. (ICES CM Documents;1989/B:5, Working paper, 1989)
      This is expressed through the effective equivalent beam angle * for cod as represented by measurements of the tilt angle dependence of target strength. The functional form of * is approximated for each of several behaviour ...

    • Acoustic sampling volume versus equivalent beam angle 

      Foote, Kenneth G. (ICES CM Documents;1988/B:5, Working paper, 1988)
      Irnprovements in target strength measurement have shown the equivalent beam angle (EBA) to be a worrisome source of error in echo integrator surveys. The reason is that the EBA is generally defined as a purely physical ...

    • Advances in Bergen Echo Integrator 

      Korneliussen, Rolf J. (ICES CM Documents;1993/B:28, Working paper, 1993)
      The Bergen Echo Integrator (BEl) is a software system designed for convenient postprocessing of echo sounder data. BEl is realized in international standards and is essentially machine independent. Development of BEl for ...

    • An automatic feeding system for culturing rotifers with dry feed 

      Strand, Bernt; Huse, Ingvar (ICES CM Documents;1985/F:42, Working paper, 1985)
      An automatic feed distribution system for culturing rotifers is described and discussed. The system has been successfully used at the Austevoll Marine Aquaculture Station for 3 years.

    • An intership sonar calibration experiment in the Norwegian Sea 

      Misund, Ole Arve; Jakupsstovu, Stein Hjalti (ICES CM Documents;1996/B:22, Working paper, 1996)
      When migrating in the Norwegian Sea in spring and summertime, the Norwegian spring spawning herring will be surveyed by vessels from four nations. Because the herring may occur in schools close to the surface, use of ...

    • Application of Coded Wire Tagging Technology in Pacific Herring to Investigate Stock Structure and Migration 

      Schweigert, Jake; Flostrand, Linnea; Slotte, Aril; Tallman, Doug; Thomas, J. O. (ICES CM documents, Working paper, 2001)
      Tagging of Pacific herring in British Columbia has a long history dating to the mid-1930s but uncertainty in tag recovery locations and low tag return rates limited the utility of these studies. Currently, a larger and ...

    • Assessing the effect of intra-haul correlation and variable density on population estimates from marine surveys 

      Pennington, Michael; Vølstad, Jon Helge (ICES CM Documents;1991/D:14, Working paper, 1991)
      In a previous paper (Pennington and Vølstad, Biometrics 47, 1991) it was suggested that reducing the size of the sampling unit generally used in marine surveys could increase the precision of abundance estimates. But if ...

    • Assessing trawl-survey estimates of frequency distributions 

      Pennington, Michael; Burmeister, Liza-Mare; Hjellvik, Vidar (ICES CM Documents;2000/K:23, Working paper, 2000)
      Marine trawl surveys catch a cluster of fish at each station and fish caught together tend to have more similar characteristics, such as length, age, stomach contents etc., than those in the entire population. When this ...

    • Assigning values of target strength and equivalent beam angle in acoustic surveys of fish 

      Foote, Kenneth G. (ICES CM Documents;1991/B:34, Working paper, 1991)
      Contrary to popular opinion, the equivalent beam angle (~) is not determined solely by the transducer directivity. Rather, like the target strength TS, it also depends on the scattering properties of the target fish, but ...

    • Automatic calibration of the sensors used in a miniature STD instrument 

      Gytre, Trygve (ICES CM Documents;1988/C:13, Working paper, 1988)
      The paper describes a system for simplified calibration of a new STD instrument. When measuring, the raw data from the instrument conductivity, temperature and pressure sensors are fed into a microprocessor inside the ...

    • Automatic recording of fish heart rate on a personal computer 

      Floen, Svein; Totland, Bjørn; Øvredal, Jan Tore (ICES CM Documents;1988/B:34, Working paper, 1988)
      From acoustic tags operated into fish in a closed system, the heartbeat signals are sent via underwater telemetry and counted on a personal computer. The computer removes false pulses caused by noise, and calculates the ...

    • Avoidance reactions of ultrasonic tagged cod during bottom trawling in shallow water 

      Engås, Arill; Soldal, Aud Vold; Øvredal, Jan Tore (ICES CM Documents;1991/B:41, Working paper, 1991)
      Introduction: Observations made by echo sounder (Ona 1988) have shown that cod (Gadus morhua L.) may avoid an approaching survey vessel horizontally and vertically. However, there has been a lack of information on the ...

    • Bad-weather calibration of split-beam echo sounder systems 

      Foote, Kenneth G. (ICES CM Documents;1990/B:22, Working paper, 1990)
      A condition for standard-target calibration is stability of the sonar platform and target rig. This condition cannot always be met, nor need it be when the transducer has a split-beam function. Since the position of ...

    • Basic studies of Norwegian longline gear 

      Karlsen, Ludvig (ICES CM Documents;1976/B:27, Working paper, 1976)

    • Behaviour of Atlantic salmon (Salmo salar L.) recorded by data storage tags in the NE Atlantic – implications for interception by pelagic trawls 

      Holm, Marianne; Jacobsen, Jan Arge; Sturlaugsson, Johannes; Holst, Jens Christian (ICES CM documents, Working paper, 2006)
      In a project carried out in the Nordic Seas (Northeast Atlantic) in 2002 - 2004, 413 Atlantic salmon (Salmo salar L.) were tagged with data storage tags (DST) either logging temperature and depth (StarOddi, Milli) or ...

    • Behaviour of Norwegian spring spawning herring in relation to underwater light 

      Beltestad, Arvid K.; Misund, Ole Arve (ICES CM Documents;1988/B:24, Working paper, 1988)
      The Norwegian coastal purse seiners, with shallow nets, have experienced difficulties in catching the herring due to their natura! behaviour being located too deep during day time and toe scattered during night time. ...

    • Behaviour studies on fish reaction to long lines 

      Tilseth, Snorre; Solemdal, Per; Fernö, Anders (ICES CM Documents;1978/B:22, Working paper, 1978)
      This study is a continuation of a field investigation on the behaviour of fish towards long lines, started in 1976. The present paper gives an analysis of the effect of current and time of the day on the activity of whiting ...

    • Bergen Echo Integrator: An Introduction 

      Knudsen, Hans Petter (ICES CM Documents;1989/B:9, Working paper, 1989)
      The design of a new echo integrator system is outlined. The B.E.I. is based on preprocessed data from the new SIMRAD EK500 scientific acoustic measurement system. Raw data are displayed and interpreted on a graphics ...

    • Calibration reflector 

      Foote, Kenneth G. (ICES CM Documents;1989/B:4, Working paper, 1989)
      Calibration of scientific echo sounders and integrators entails, inter alia, measurement of the dynamic range. This can be done by repeating on-axis measurements of echoes from each of two different standard targets. ...

    • Can subjective evaluation of echograms improve correlation between bottom trawl and acoustic densities? 

      Godø, Olav Rune; Hjellvik, Vidar; Greig, Tony; Beare, Douglas (ICES CM documents, Working paper, 2004)
      Direct comparison of acoustic densities and trawl catches involves fundamental difficulties related to species and size selectivity of the trawl and efficiency of the acoustic instrumentation. In some surveys, therefore, ...