Blar i Brage IMR på emneord "VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924"
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Comparison of Northeast Atlantic mackerel (Scomber scombrus) distribution patterns in the Norwegian Sea using lidar, sonar, and trawl
(ICES CM documents, Working paper, 2003)In July 2002 the Institute of Marine Research (IMR), Bergen mapped the distribution and density of mackerel in the Norwegian Sea using lidar, sonar and trawl. A major objective was to test the efficiency of the lidar as ... -
Comparison of Norwegian and Russian trawl performance: Preliminary analysis of cod data
(Working paper, 1998) -
Comparison of two 120-kHz split-beam transducers
(ICES CM Documents;1991/B:31, Working paper, 1991)The performance of two 120-kHz split-beam transducers is compared through the following measures: relative power level, directivity index, relative source level, and reverberation index or equivalent beam angle. Sidelobe ... -
Comparisons between size distribution in surveys and commercial catches: a useful tool for monitoring changes in the size selection in the fisheries?
(IMR/PINRO Joint Report Series, Conference object, 2001)A method is proposed for using fish distributions from standarized research surveys for estimating relative selection in the fisheries. The method is applied on data for North-east arctic cod in the 1990-ies. Survey-related ... -
Comparisons between size distribution in surveys and commercial catches: a useful tool for monitoring changes in the size selection in the fisheries?
(IMR/PINRO Joint Report Series, Conference object, 2001)A method is proposed for using fish distributions from standarized research surveys for estimating relative selection in the fisheries. The method is applied on data for North-east arctic cod in the 1990-ies. Survey-related ... -
Computerbased detection of schools for counting, quantification of size and swimming behavior by the SIMRAD SA950 sonar
(ICES CM Documents;1993/B:17, Working paper, 1993)As a help in stock assessment of pelagic, schooling fish a software for detection of schools and quantification of their size and swimming behaviour by a high resolution sonar has been developed. The system reads the ... -
Contributions from Fiskeridirektoratets Havforskningsinstitutt
(Fiskeridirektoratets skrifter, Serie Havundersøkelser;vol 13 no 7, Research report, 1964) -
Contributions given in honour of Einar Koefoed's 60 yearsservice in Norwegian fisheries research 1902-1962
(Fiskeridirektoratets skrifter, Serie Havundersøkelser;vol 13 no 6, Research report, 1963) -
Correcting for avoidance in acoustic abundance estimates for herring using a generalized linear model
(ICES CM documents, Working paper, 2006)When a research vessel passes over a herring school or layer, the herring may avoid the vessel by swimming downwards and horizontally. The fish may also change its orientation, which may alter its mean target strength. ... -
CRISP- Toktrapport. Testing trålutstyr og instrumentering. G. O. Sars 1.-11. mars 2015
(Rapport fra havforskningen;10-2016, Research report, 2016) -
Cylindrical sonar design for fish echo surveying
(ICES CM Documents;1988/B:3, Working paper, 1988)Most applications of echo integration involve use of a fixed single-beam transducer that is rather narrow and downwards-oriented. It is often desired to sense fish in other directions, for example, to assess components ... -
Day / night variation in fish directivity in the trawl opening
(ICES CM Documents;1994/B:18, Working paper, 1994)Still photographs of fish in the mouth area of a bottom trawl were taken by a downwards-oriented automated strobe camera mounted near the headrope. Fish angles relative to the towing direction were measured. Fish were ... -
Day and night fish distribution pattern in the net mouth area of the Norwegian bottom-sampling trawl
(Journal article; Peer reviewed, 1990)A high-frequency scanning sonar, mounted as a net sonde, was used to study fish behaviour in the mouth area of the Norwegian bottom-sampling trawl. Fish distribution patterns were significantly different by day and night. ... -
Deep towed vehicle for fish abundance estimation concept and testing
(ICES CM Documents;1991/B:53, Working paper, 1991)A research program was initiated in Norway in 1988 for measuring the abundance of fish resources at depth from 500 to 1000 metres. It was decided to develope a deep towed vehicle, to bring acoustic transducers down to ... -
Definition of the problem of estimating fish abundance over an area from acoustic line-transect measurements of density
(ICES CM Documents;1990/D:25, Working paper, 1990)The problem of acoustic abundance estimation is briefly reviewed. Under proper conditions, fish density can be measured with high accuracy along line transects. Observed variations in fish density consequently reflect ... -
Demersal pair trawling and its operational parameters.
(ICES CM Documents;1982/B:36, Working paper, 1982) -
Designing an improved transducer array geometry
(ICES CM Documents;1988/B:2, Working paper, 1988)Improvements in a split-beam transducer that is also used for surveying are sought through changes in array geometry. These are assessed through relative changes in the sum of source level and voltage response and the ... -
Designing an Ocean Mid-trophic Automatic Acoustic Sampler (MAAS) - thoughts on how to include echo sounder observatories in ecosystem models
(ICES CM documents;2009/I:21, Working paper, 2009)Echo sounders are a widely used tool for observing marine ecosystems. Traditionally, carefully designed surveys are used to integrate biomass to a global estimate, which is coupled to traditional stock assessment models. ... -
Detailed in situ target strength measurements of 0-group cod
(ICES CM Documents;1994/B:30, Working paper, 1994)Target strength measurements in situ of cod fry have been made using 38 and 120 kHz split beam echo sounders. Two data sets are sampled in essentially pure, evenly sized, cod concentrations, one in a Ullsfjord, Northern ...