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 21-40 of 158
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Behavioural rhythm of cod during migration in the Barents Sea
(ICES CM Documents;2000/K:34, Working paper, 2000)To assess fish abundance by direct methods and to understand and model species interaction, it is important to have proper knowledge about behavioural patterns. Patterns in vertical distribution might strongly affect ... -
Can Pitch & Roll DST distinguish between pelagic and demersal behaviour of adult Greenland halibut
(ICES CM documents, Conference object, 2006) -
Cannibalism as a factor regulating year class strength in the Norwegian spring-spawning herring stock
(ICES CM Documents;1992/H:14, Working paper, 1992)The feeding area of the Norwegian spring-spawning herring stock is at present situated in the north-eastern parts of the Norwegian Sea. The eastern parts of the feeding area overlaps with the distribution of drifting ... -
Catfish - King of the sea
(ICES CM Documents;1995/B:16, Working paper, 1995)During an acoustic tagging experiment on cod in the Barents Sea in March 1995 a hierarchy between different fish species was revealed, and the catfish (Anarhichas sp.) was observed to be dominant in relation to cod and ... -
Changes on horse mackerel (Trachurus trachurus) catch distribution in the Northeast Atlantic
(ICES CM Documents;1996/S:26, Working paper, 1996)The distributions of international commercial catch data were mapped by ICES rectangle and quarter from 1983-1994. These indicate a northward expansion of horse mackerel distribution in the Northeast Atlantic since 1987. ... -
Comparative habitat use and foraging behaviour of harbour seals and grey seals in Western Norway
(ICES CM Documents;1995/N:1, Working paper, 1995)Adult harbour seals at Froan nature reserve, Central Norway, were tagged with VHF radio tags and depthvelocity, hart rate and stomach temperature sensors combined with ultrasonic transmitters. An automatic shore based ... -
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 ... -
Data on the 1983 year class of Norwegian spring spawning herring from the period June 1985 -August 1986
(ICES CM Documents;1986/H:19, Working paper, 1986)This paper considers the distribution, growth and migration of the 1983 year class of Norwegian spring spawning herring. There are, at present, two geographical components of this year class, one component with a nursery ... -
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 ... -
Density dependent catchability in bottom trawl surveys
(ICES CM Documents;1997/W:16, Working paper, 1997)Fish form schools, layer or patches in which the individual fish's behaviour is not independent of its neighbours movements. On the other hand, at low densities fish may have the freedom to act as single individuals ... -
Detection of spatial distribution of acoustic categories
(ICES CM documents, Working paper, 2005) -
Diet of harp seals (Phoca groenlandica) feeding between the breeding and moulting seasons in the southern Barents and White Seas
(ICES CM Documents;1993/N:8, Working paper, 1993)The harp seal Phoca groenlandica is the most abundant seal species in the Barents Sea. In order to evaluate the ecological importance of the species, diet studies have recently been carried out at various times of the ... -
Distribution and growth of blue whiting in the north-east Atlantic
(ICES CM Documents;1990/H:14, Working paper, 1990)The distribution pattern of the blue whiting spawning stock has gradually changed in recent years, and concentrations are recorded more offshore and more to the south than before. The activity of the fleet with its ... -
Distribution of Norwegian spring-spawning herring and mackerel in the Norwegian Sea in late summer, 1991
(ICES CM Documents;1992/H:13, Working paper, 1992)A pairtrawl survey was carried out in the Norwegian Sea during July - August 1991 to map the distribution of pelagic fish. Herring were caught throughout most of the surveyed area, with the largest concentrations observed ... -
Diurnal variations in acoustic density measurements of wintering Norwegian spring spawning herring
(ICES CM Documents;1995/B:12, Working paper, 1995)Survey data from six herring assesment cruises in the wintering areas for spring spawning Norwegian herring were analysed with regard to variation in abundance and depth with time of day. The data were quite consistant ... -
Dynamics of moving masses: Variability in packing density and shape among pelagic schools
(ICES CM Documents;1990/B:40, Working paper, 1990)The packing density and external shape of herring, saithe and sprat schools in the North Sea and along the Norwegian coast are measured acoustically. The packing density was inversely. related to the fish size, but species ... -
Dynamics of wintering Norwegian spring-spawning herring at the entrance to Tysfjorden, December 1996
(ICES CM Documents;1997/CC:16, Working paper, 1997)The entrance region to Tysfjorden was acoustically surveyed a total of eleven times during the December 1996 abundance survey of the spawning stock of Norwegian spring-spawning herring (Clupea harengus). The observations ... -
Effect of swimming on fish target strength
(ICES CM Documents;1985/B:29, Working paper, 1985)The influence of the swimming movement on fish target strength is investigated through a modelling exercise. In this, several gadoid specimens are represented as acoustic scatterers through their triangulated swimbladder ... -
Effects of pre-release acclimatization period on salmon return rates
(ICES CM Documents;1995/M:13, Working paper, 1995)42.000 1+smolts of Atlantic salmon were size graded into two size groups and released during three weeks in spring 1993; one group of small and one of large smolts on each of the four release days. Approximately 25% of ... -
Effects on salmon (Salmo salar) from different operational procedures in fish farming
(ICES CM Documents;1988/F:16, Working paper, 1988)The effects on farmed salmon caused by operational procedures as handling, de-lousing, removal of dead fish, grading and transfer were studied by underwater TV-observations, ultrasonic telemetry of heart rate and analyses ...