How vertical fish distribution may affect survey results
At a selected location in the Barents Sea, acoustic observations were made and bottom- and pelagic-trawl data were collected over a 10-day period. A large proportion of fish were found in the acoustic bottom dead zone. Only during a few hours in the daytime were high acoustic values obtained, mainly...
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1999
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fthighwire:oai:open-archive.highwire.org:icesjms:56/3/345 2023-05-15T15:38:56+02:00 How vertical fish distribution may affect survey results Aglen, A. Engås, A. Huse, I. Michalsen, K. Stensholt, B. K. 1999-06-01 00:00:00.0 text/html http://icesjms.oxfordjournals.org/cgi/content/short/56/3/345 https://doi.org/10.1006/jmsc.1999.0449 en eng Oxford University Press http://icesjms.oxfordjournals.org/cgi/content/short/56/3/345 http://dx.doi.org/10.1006/jmsc.1999.0449 Copyright (C) 1999, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer Articles TEXT 1999 fthighwire https://doi.org/10.1006/jmsc.1999.0449 2013-05-27T05:24:57Z At a selected location in the Barents Sea, acoustic observations were made and bottom- and pelagic-trawl data were collected over a 10-day period. A large proportion of fish were found in the acoustic bottom dead zone. Only during a few hours in the daytime were high acoustic values obtained, mainly consisting of large haddock ascending from the bottom. Small haddock and redfish dominated the acoustic recordings at night. The bottom-trawl catches showed greater variability and higher average catch rates during the day than at night, but the diel variations were relatively less pronounced than those of the acoustic recordings. The largest reductions in catch rates from day to night were observed in small haddock and redfish. This was consistent with the observation that these species were pelagic at night. The acoustic observations and the bottom-trawl catch rates were found to be correlated with diel cycles in observed light level and semi-diel cycles in current speed. The results are interpreted in terms of the variable availability and efficiency of the bottom trawl and of the variable availability of the echosounder. Text Barents Sea HighWire Press (Stanford University) Barents Sea ICES Journal of Marine Science 56 3 345 360 |
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HighWire Press (Stanford University) |
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English |
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Articles Aglen, A. Engås, A. Huse, I. Michalsen, K. Stensholt, B. K. How vertical fish distribution may affect survey results |
topic_facet |
Articles |
description |
At a selected location in the Barents Sea, acoustic observations were made and bottom- and pelagic-trawl data were collected over a 10-day period. A large proportion of fish were found in the acoustic bottom dead zone. Only during a few hours in the daytime were high acoustic values obtained, mainly consisting of large haddock ascending from the bottom. Small haddock and redfish dominated the acoustic recordings at night. The bottom-trawl catches showed greater variability and higher average catch rates during the day than at night, but the diel variations were relatively less pronounced than those of the acoustic recordings. The largest reductions in catch rates from day to night were observed in small haddock and redfish. This was consistent with the observation that these species were pelagic at night. The acoustic observations and the bottom-trawl catch rates were found to be correlated with diel cycles in observed light level and semi-diel cycles in current speed. The results are interpreted in terms of the variable availability and efficiency of the bottom trawl and of the variable availability of the echosounder. |
format |
Text |
author |
Aglen, A. Engås, A. Huse, I. Michalsen, K. Stensholt, B. K. |
author_facet |
Aglen, A. Engås, A. Huse, I. Michalsen, K. Stensholt, B. K. |
author_sort |
Aglen, A. |
title |
How vertical fish distribution may affect survey results |
title_short |
How vertical fish distribution may affect survey results |
title_full |
How vertical fish distribution may affect survey results |
title_fullStr |
How vertical fish distribution may affect survey results |
title_full_unstemmed |
How vertical fish distribution may affect survey results |
title_sort |
how vertical fish distribution may affect survey results |
publisher |
Oxford University Press |
publishDate |
1999 |
url |
http://icesjms.oxfordjournals.org/cgi/content/short/56/3/345 https://doi.org/10.1006/jmsc.1999.0449 |
geographic |
Barents Sea |
geographic_facet |
Barents Sea |
genre |
Barents Sea |
genre_facet |
Barents Sea |
op_relation |
http://icesjms.oxfordjournals.org/cgi/content/short/56/3/345 http://dx.doi.org/10.1006/jmsc.1999.0449 |
op_rights |
Copyright (C) 1999, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer |
op_doi |
https://doi.org/10.1006/jmsc.1999.0449 |
container_title |
ICES Journal of Marine Science |
container_volume |
56 |
container_issue |
3 |
container_start_page |
345 |
op_container_end_page |
360 |
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1766370364702588928 |