Browsing Brage IMR by Subject "VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924"
Now showing items 281-300 of 725
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Nytt trålegear med redusert bunnkontakt : New trawl gear with reduced bottom contact
(Havforskningsnytt;Nr. 2 - 2010, Working paper, 2010) -
Nyvinninger i kø for nystartet senter
(Havforskningsnytt;Nr. 2 - 2012, Working paper, 2012)I 2011 kunne fiskere og forskere stå på broen på fiskebåten og følge med på direkte videooverføring av fisk som gikk inn i trålen. Tråldører med justerbare luker og et system som automatisk identifiserer og sorterer fisk ... -
Observasjoner i faste oseanografiske snitt fram til år 2012
(Research report, 2012-06)Dette heftet gir en oversikt over faste snitt som Havforskningsinstituttet har dekket fram t.o.m. år 2011. Havforskningsinstituttet har gjennom årene gjort observasjoner langs tallrike mer eller mindre faste kurser. En ... -
Observation of fish behaviour, density and distribution around a surveying vessel by means of a deployable echo sounder system
(ICES CM Documents;1999/J:9, Working paper, 1999)Detailed acoustic observations of fish behaviour, distribution and density in the trawl area are necessary in order to establish quantitative relationships between trawl samples and fish density. Acoustic observation ... -
Observation of fish behaviour, density and distribution around a surveying vessel by means of a deployable echo sounder system
(ICES CM documents, Working paper, 1999)Detailed acoustic obsewations of fish behaviour, distribution and density in the trawl area are necessary in order to establish quantitative relationships between trawl samples and fish density. Acoustic observation close ... -
Observations of cod reaction to trawling noise
(Working paper, 1988-04)Observations made from a stationary echo sounder, passed by a trawling vessel, clearly demonstrate the flight reaction of cod as a response to the noise from the vessel. Horizontal dispersal and downward swimming has been ... -
Observations on the Depth Range of tagged Bluefin Tuna (Thunnus thynnus L.) based on Pressure Marks on the Lea Tag
(ICES CM Documents, Working paper, 1964)The present paper is an investigation on the depth range of tagged bluefin tuna based on pressure marks on the Lea tag (Figure 1). It was observed that the within season recaptures were without pressure marks, while the ... -
Observer program for juvenile Northeast Arctic saithe
(Working paper, 2010-02)NEA saithe 0-group indices from observers along the coast does not seem to reflect the dynamics in year class strength very well and is therefore probably not suitable for improving future recruitment estimates for this stock. -
Observing school dynamics in situ using acoustics
(Conference object, 2010-04) -
Observing the behavioral response of herring exposed to mid-frequency sonar signals. (A)
(Conference object, 2010-03)There is general concern on how mid-frequency military sonars might affect aquatic animals. Approaches used to investigate possible effects on Norwegian spring spawning herring (Clupea harengus) are presented. Experiments ... -
Observing the behavioral response of herring exposed to mid-frequency sonar signals. (A)
(Conference object, 2010-03)There is general concern on how mid-frequency military sonars might affect aquatic animals. Approaches used to investigate possible effects on Norwegian spring spawning herring (Clupea harengus) are presented. Experiments ... -
On acoustic multi-frequency species identification and separation of Atlantic mackerel, Norwegian spring spawn herring and Norway pout.
(ICES CM documents, Working paper, 2004)The accuracy of the multi-frequency species identification and separation algorithms may be significantly improved when the detailed acoustic scattering characteristics of the fish are known, including its expected variability ... -
On subjectivity in the judging of acoustic records; comparison of degree of homogenity in allocation of echo values by different teams
(ICES CM Documents;1993/B:21, Working paper, 1993)On four fish abundance estimation surveys in the Barents Sea, january-february 1993, the acoustic records were judged by two independent teams. We have analyzed the degree of homogenity in allocation of echo values to ... -
On the depth dependence of fish target strength
(ICES CM Documents;1997/FF:7, Working paper, 1997)Data on the depth dependence of the target strength of live kokanee (Oncorhynchus nerka), a physostome, at 50 kHz (Mukai, T., and Iida, K., ICES J. mar. Sci., 53: 245-248 (1996)) have been reexamined. In the cited study, ... -
On the Estimation of Cod and Haddock discarded by Trawlers using different Chafers
(ICES CM Documents;1965/167, Working paper, 1965) -
On the frequency dependence of target strength of mature herring
(ICES CM Documents;1992/B:10, Working paper, 1992)Mature herring (Clupea harengus), hibernating in Ofotfjord in December 1991, was measured simultaneously at each of three frequencies: 18, 38, and 120 kHz. Measurements of the mean volume backscattering coefficient were ... -
On the shape, size and density of North Sea herring schools as mapped by echo integration and accurate sonar projection
(ICES CM Documents;1993/B:16, Working paper, 1993)The shape and horizontal extent of herring schools in the North Sea have been mapped by a naval sonar (SIMRAD SA 950) with narrow horizontal beam width. The density of schools that were passed over was measured by the ... -
Operating Experiences with an ultrasonic current meter
(ICES CM Documents;1974/C:29, Working paper, 1974) -
Operational Data distribution at Institute of Marine Reasearch
(ICES CM documents;2010:A14, Working paper, 2010)The Norwegian marine datacenter (NMD) started serving operational research data from vessels operated by the Institute of Marine Research in the early 2000. Through the EU FP7 project MyOcean NMD has become the thematic ... -
Optimal acoustic beam pattern corrections for split beam transducers
(ICES CM Documents;1990/B:30, Working paper, 1990)Precise in situ target strength estimates of fish can only be made when the effect of the transducer directivity is totally removed from the recorded target amplitudes. By guiding a standard calibration target through the ...