Browsing ICES CM documents authored by IMR scientists (1949-2011) by Subject "VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485"
Now showing items 61-80 of 158
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Migration behaviour of Norwegian spring spawning herring when entering the cold front in the Norwegian Sea
(ICES CM Documents;1996/H:13, Working paper, 1996)The distribution of Norwegian spring spawning herring when migrating to the feeding areas in the Norwegian Sea in spring has been mapped by surveys in April1995 and 1996. The schooling behaviour of the herring have been ... -
Migratory behaviour of reared Norwegian coastal cod and north east Arctic cod
(ICES CM Documents;1995/G:11, Working paper, 1995)This paper is based on experiments to test if differences in migratory behaviour of Norwegian coastal cod and north east Arctic cod is related to parental origin or, alternatively, is related to the environmental experienced ... -
Migratory patterns of escaped farmraised Atlantic salmon
(ICES CM Documents;1990/F:55, Working paper, 1990)Simulated escapes of farmed salmon from netpens are done. Migratory behaviour and routes are studied by combining acoustic tagging and standard tagging - release methodology. A prototype of a recapture trap has been ... -
Monitoring changes in abundance of gadoids with varying availability to surveys
(ICES CM Documents;1991/G:76, Working paper, 1991)The use of scientific survey data for assessing abundance of commercially important fish stocks has become a managerial necessity in many regions. Errors and bias in estimates from such surveys may thus have great economic ... -
Natural fish behaviour and catchability of groundfish
(ICES CM Documents;1994/G:14, Working paper, 1994)Imprecision in estimates of abundance and population parameters obtained from trawl surveys could be reduced if the sources of variability were understood and properly described. Fish behaviour in relation to sampling ... -
Near-bottom sampling with bottom and pelagic trawls
(ICES CM Documents;1987/B:15, Working paper, 1987)The Institute of Marine Research, Bergen, has carried out combined bottom trawl and acoustic surveys for cod and haddock in the Barents Sea - Svalbard area since 1981. These investigations have demonstrated clearly that ... -
NORFISK - an ecosystem simulation model for studies of the fish stocks off the coast of Norway
(ICES CM Documents;1984/B:25, Working paper, 1984)A biomass based ecosystem simulation model has been fitted to a restricted area of the Norwegian coastal waters. The model uses a holistic ecosystem approach and data on biomasses and their interaction with each other ... -
Numerical domination and herring migrations
(ICES CM documents, Working paper, 2006)There is accumulating evidence in favour of the hypothesis that herring migrations are influenced by social learning. The “adopted-migrant hypothesis” postulates that recruit spawning herring learn migration patterns by ... -
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 ... -
Observations of cod behaviour reveal insights into the function and properties of the swimbladder under pressure
(ICES CM documents, Working paper, 2006)Atlantic cod (Gadus morhua L.) is a highly adaptive boreal species with a broad distribution through different ecosystems in the North Atlantic. Diet, environmental factors and population dynamics vary enormously ... -
Observing behaviour of over-wintering Herring (Clupea harrengus L.) in Ofoten with Acoustic Current profiler
(ICES CM Documents;2003/Q:6, Working paper, 2003)In this paper we present results and interpretation of velocity and signal strength data collected with a ‘Continental’ Current Profiler on over-wintering herring in the Ofoten in the North of Norway. The instrument was ... -
On multiple scattering in fisheries acoustics
(ICES CM Documents;1982/B:38, Working paper, 1982) -
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 ... -
PC-based echo integration system for fish behaviour studies
(ICES CM Documents;1988/B:35, Working paper, 1988)An echo integration system presenting the distribution and vertical and horizontal movements of fish in net pens, is described. The system can be configured to multiplex up to 16 transducers sequentially. The number of ... -
Pelagic occurrence of Greenland halibut (Reinhardtius hippoglossoides) studied by means of vertical longlines
(ICES CM Documents;2004/K:69, Working paper, 2004)In order to calculate reliable survey indices it’s important to know the dynamics of vertical distribution of a fish species. The vertical distribution of Greenland halibut (Reinhardtius hippogolossoides) cannot be studied ... -
Position prediction of herring schools in purse-seine capture situations
(ICES CM Documents;1987/B:10, Working paper, 1987)Sonar observations of herring schools in the North Sea and along the Norwegian Coast reveal a rather constant swimming behaviour of individual schools in purse-seine capture situations. On the basis of this a method for ... -
Qualitative and quantitative behaviour studies in starving and feeding turbot (Scopthalmus maximus L.) larvae
(ICES CM Documents;1985/F:38, Working paper, 1985)A computer aided video system was used to register three dimensional movement and behaviour patterns in starving and feeding turbot larvae. The feeding larvae were kept and were monitored beyond metamorphosis in the ... -
Recent migration routes of Norwegian spring spawning herring
(ICES CM Documents;1992/H:18, Working paper, 1992)The migration routes of Norwegian spring spawning herring have changed considerably during the last decades. In the 1950s and beginning of the 1960s the stock spawned off the west coast of Norway in late winter, were ... -
Relationships between the geometric dimensions and biomass of schools
(ICES CM Documents;1990/B:41, Working paper, 1990)Acoustic measurements of the geometric dimensions and packing density of herring, sprat and saithe schools have been conducted by multi-beam sonars and echo integrator systems. Relationships between the reflected echo ... -
Report by special joint session on the methods for observing gear and the reactions of fish to gear
(ICES CM Documents;1976/B:3, Working paper, 1976)