Browsing ICES CM documents authored by IMR scientists (1949-2011) by Subject "gear experiments"
Now showing items 101-117 of 117
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School geometry measurements using a sonar accuracy and an algorithm for school detection
(ICES CM Documents;1991/B:36, Working paper, 1991)The accuracy of geometric measurements of schools, using horizontal guided single-beam or multi-beam sonar, is simulated. For both types of sonars, the accuracy is dependent of horizontal beam-width and range. As multiple ... -
Selectivity experiments with a cod-end made of polypropylene splitfiber
(ICES CM Documents;1967/B:10, Working paper, 1967) -
Selectivity experiments with a large-meshed topside chafer
(ICES CM Documents;1966/F:13, Working paper, 1966) -
Selectivity experiments with square mesh codends in bottom trawl
(ICES CM Documents;1986/B:28, Working paper, 1986)During selectivity experiments with square and diamond mesh codends, an evaluation of the covered codend method and a modified trouser trawl method went in favour of the last one. Both twisted knotless- and braided ... -
Selectivity experiments with topside chafers and round straps
(ICES CM Documents;1977/B:38, Working paper, 1977) -
Size selective effects of a plastic body on longline hooks
(ICES CM Documents;1991/B:46, Working paper, 1991)The potential for improving size selectivity of longlines by using a plastic body attached to the hook shank was tested in a fishing trial for tusk (Brosme brosme), ling (Molva molva) and haddock (Melanogrammus aeglefinus). ... -
Some pitfalls of short-range standard-target calibration
(ICES CM Documents;1996/B:36, Working paper, 1996)Often it is necessary or desirable to perform a standard-target calibration at rather short range, for example, because of shallow water or interest in measuring animals at short range. A number of general range-dependent ... -
Spheres for calibrating an eleven-frequency acoustic measurement system
(ICES CM Documents;1989/B:3, Working paper, 1989)Calibration of a single resonant transducer by standard sphere is a simple matter. How does one calibrate an array composed of eleven different resonant transducers spanning the frequency range from 27 to 710 kHz? A ... -
Test experiments of target strength of herring by comparing density indices obtained by acoustic method and purse seine catches
(ICES CM Documents;1994/B:17, Working paper, 1994)The spawning stock of the Norwegian spring spawning herring has been assessed by acoustic methods using the target strength TS = 20 logL - 71.9 dB (L = mean length of fish) Comparable estimates of fish density were ... -
Testing of a new hook design (E-Z-Baiter) through comparative longline fishing trials
(ICES CM Documents;1986/B:25, Working paper, 1986) -
Testing of a new hook design in the longline fishery for tusk (Brosme brosme) and ling (Molva molva)
(ICES CM Documents;1987/B:20, Working paper, 1987)The EZ-Baiter Circle hook which is a hybrid design between the classical J- and Circle hook shapes, is developed to provide a more effective hook for use in mechanized longline systems. In comparative fishing trials, ... -
The development of a new gillnet fishery for anglerfish (Lophius piscatorius) in Norwegian waters
(ICES CM Documents;1995/G:12, Working paper, 1995)In autumn 1992 a direct gillnet fishery for anglerfish (Lophius piscatorius) started on the continental shelf off the northwestern coast of Norway. The anglerfish had previously only been taken as bycatch in trawls and ... -
An ultrasonic current meter
(ICES CM Documents;1971/C:24, Working paper, 1971) -
Use of derrick scales for weighing live fish
(ICES CM Documents;1981/F:40, Working paper, 1981)In Norway purse seine catches of saithe are usually sold to the factories alive. The fish is transported in boats specially constructed for the transport, i.e. well-boats. The saithe is weighed when transferred to these ... -
Vertical entrance into a trawl of Barents Sea gadoids as studied with a two level fish trawl
(ICES CM Documents;1985/B:46, Working paper, 1985)Catch figures of different demersal species(cod, haddock, saithe etc.) in the cod-ends of a two level trawl were examined using variable height of the separating panel (0.5, 0.75, 1.0 and 1.5 m). Cod enters the trawl ... -
Voice controlled form filling
(ICES CM Documents;1991/C:22, Working paper, 1991)During field work in the sea - in particular when collecting data like weight, length, sex, stadium, etc. from fish samples, the observations are first manually noted in a standardized sampling form. One popular form ... -
Vulnerability to predation of small cod (Gadus morhua) that escape from a trawl
(ICES CM Documents;1995/B:15, Working paper, 1995)Studies of the vulnerability to gear damage of fish that have been caught in a trawl but have escaped through the codend meshes have focussed on determining survival rates. This study examines the risk of predation in ...