Blar i ICES CM documents authored by IMR scientists (1949-2011) på forfatter "Dalen, John"
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Acoustic method for estimating absolute abundance of young cod and haddock in the Barents Sea
Dalen, John; Smedstad, Odd M. (ICES CM documents, Working paper, 1979) -
Acoustic survey of deep-water fish of the Skagerrak
Bergstad, Odd Aksel; Gordon, John D.M.; Dalen, John (ICES CM Documents;1992/H:15, Working paper, 1992)Introduction: Two fish species, the greater silver smelt Argentina silus and the roundnose grenadier Coryphaenoides rupestris, are highly abundant in the deep-water areas of the Skagerrak. Since the 1970s, a small aimed ... -
Characteristics of sardinella aggregations in Angolan waters
Dalen, John; Misund, Ole Arve; Luyeye, Nkosi; Boyer, D.; Coetzee, Janet; Cloete, Rudi; Oechslin, Gerhard (ICES CM documents, Working paper, 1998) -
Deep towed vehicle for fish abundance estimation concept and testing
Dalen, John; Bodholt, Helge (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 ... -
Density in sub-arctic zooplankton
Falk-Petersen, Stig; Køgeler, J. W.; Kristensen, Åge; Pettersen, Fritz; Dalen, John (ICES CM documents, Working paper, 1985)Seasonal variations in specific density were measured for Thysanoessa inermis, Thysanoessa raschii, Meganyctiphanes norvegica, Calanus finmarchicus and Calanus hyperboreus. The density of a 20 mm T. inermis was lowest in ... -
Investigations on demersal fish in the Barents Sea in winter 1977
Dalen, John; Hylen, Arvid; Smedstad, Odd M. (ICES CM Documents;1977/F:23, Working paper, 1977) -
Measurements of Target stength and Spatial Orientation of Euphausiids (krill).
Dalen, John; Kristensen, Åge (ICES CM Documents;1981/B:l7, Working paper, 1981) -
Monitoring fish communities at drifting FADs: an autonomous system for data collection in an ecosystems approach
Brehmer, Patrice; Sancho, Gorka; Josse, Erwan; Taquet, Marc; Georgakarakos, Stratis; Itano, David; Moreno, Gala; Palud, Pierre; Trygonis, Vasilis; Aumeeruddy, Riaz; Girard, Charlotte; Peignon, Christophe; Dalen, John; Dagorn, Laurent (ICES CM documents;2009, Theme session I, Working paper, 2009)An increasing proportion of landings by tuna purse seine fishing vessels are taken around drifting Fish Aggregating Devices (FADs). Although these FADs and their use by the fishing industry to capture tropical tuna have ... -
Norwegian investigations on young cod and haddock in the Barents Sea during the winter 1982
Dalen, John; Hylen, Arvid; Nakken, Odd; Randa, Kjell; Smedstad, Odd M. (ICES CM documents, Working paper, 1982)An acoustic survey and a bottom trawl survey were carried out in the Barents Sea during winter 1982. Both surveys showed that there has been a reduction in the total number of cod of about 50% and about 75% for haddock in ... -
On the application of the echointegration method
Dalen, John; Nakken, Odd (ICES CM documents;1983/B:19, Working paper, 1983)The echo integration method used by the Institute of Marine Research is described. The model which are used to convert acoustic abundance indices into fish densities using length and species dependant conversion factors, ... -
Preliminary report of the Norwegian investigations on young cod and haddock in the Barents Sea during the winter 1982
Nakken, Odd; Dalen, John; Hylen, Arvid; Randa, Kjell; Smedstad, Odd M. (ICES CM documents, Working paper, 1983)An acoustic survey and a bottow trawl survey for cod and haddock were carried out in the Barents Sea during the winter 1983. The two surveys gave different results. The acoustic survey showed a 50 % reduction from 1982 for ... -
Preliminary reports of the Norwegian investigations on young cod and haddock in the Barents Sea during the winter 1984
Nakken, Odd; Dalen, John; Hylen, Arvid; Randa, Kjell; Jakobsen, Tore (ICES CM documents, Working paper, 1984)An acoustic survey and a bottom trawl survey for cod and haddock were carried out in the Barents Sea during the winter 1984. The two surveys gave different results, both in absolute terms and when changes from the 1983 ... -
Relationships between the geometric dimensions and biomass of schools
Misund, Ole Arve; Aglen, Asgeir; Beltestad, Arvid K.; Dalen, John (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 ... -
Target strength measurements and acoustic biomass estimation of capelin and 0-group fish
Dalen, John; Raknes, Askjell; Røttingen, Ingolf (ICES CM documents, Working paper, 1976)