Reliability of trawl surveys on cod in Norwegian fjords
<qd> Lunde, T. M., Godø, O. R., and Rosland, R. 2008. Reliability of trawl surveys on cod in Norwegian fjords. – ICES Journal of Marine Science, 65. </qd>According to ICES, the International Council for the Exploration of the Sea, populations of coastal cod (CC) in Norway north of 62°N h...
Published in: | ICES Journal of Marine Science |
---|---|
Main Authors: | , , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
2008
|
Subjects: | |
Online Access: | http://icesjms.oxfordjournals.org/cgi/content/short/fsn068v1 https://doi.org/10.1093/icesjms/fsn068 |
id |
fthighwire:oai:open-archive.highwire.org:icesjms:fsn068v1 |
---|---|
record_format |
openpolar |
spelling |
fthighwire:oai:open-archive.highwire.org:icesjms:fsn068v1 2023-05-15T14:30:27+02:00 Reliability of trawl surveys on cod in Norwegian fjords Lunde, T. M. Godø, O. R. Rosland, R. 2008-05-01 22:15:33.0 text/html http://icesjms.oxfordjournals.org/cgi/content/short/fsn068v1 https://doi.org/10.1093/icesjms/fsn068 en eng Oxford University Press http://icesjms.oxfordjournals.org/cgi/content/short/fsn068v1 http://dx.doi.org/10.1093/icesjms/fsn068 Copyright (C) 2008, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer Article TEXT 2008 fthighwire https://doi.org/10.1093/icesjms/fsn068 2013-05-26T22:26:33Z <qd> Lunde, T. M., Godø, O. R., and Rosland, R. 2008. Reliability of trawl surveys on cod in Norwegian fjords. – ICES Journal of Marine Science, 65. </qd>According to ICES, the International Council for the Exploration of the Sea, populations of coastal cod (CC) in Norway north of 62°N have been declining since 1994. The estimates are based on analytical assessment in which the most recent estimates are tuned with survey information. We evaluate the quality of bottom-trawl surveys conducted in four North Norwegian fjords during autumn of the years 1995–2004. Surveys tended to be carried out later in autumn in the more recent years than in the earlier years. Consequently, there was a significant decrease in sun's altitude from 1995 to 2004 at the time the surveys were carried out. Further inconsistency among years dominated when comparing catch per unit effort (cpue) by year class and age over time. Often, the observed cpue at age a + 1 in year y + 1 was greater than in year y at age a . Spearman’s rank correlation of cpue vs. year also demonstrated inconsistencies in the data. The problems related to separating CC and northeast Arctic cod are discussed. Text Arctic cod Arctic Northeast Arctic cod Lunde HighWire Press (Stanford University) Arctic Lunde ENVELOPE(50.467,50.467,-66.967,-66.967) Norway ICES Journal of Marine Science 65 6 937 945 |
institution |
Open Polar |
collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Article |
spellingShingle |
Article Lunde, T. M. Godø, O. R. Rosland, R. Reliability of trawl surveys on cod in Norwegian fjords |
topic_facet |
Article |
description |
<qd> Lunde, T. M., Godø, O. R., and Rosland, R. 2008. Reliability of trawl surveys on cod in Norwegian fjords. – ICES Journal of Marine Science, 65. </qd>According to ICES, the International Council for the Exploration of the Sea, populations of coastal cod (CC) in Norway north of 62°N have been declining since 1994. The estimates are based on analytical assessment in which the most recent estimates are tuned with survey information. We evaluate the quality of bottom-trawl surveys conducted in four North Norwegian fjords during autumn of the years 1995–2004. Surveys tended to be carried out later in autumn in the more recent years than in the earlier years. Consequently, there was a significant decrease in sun's altitude from 1995 to 2004 at the time the surveys were carried out. Further inconsistency among years dominated when comparing catch per unit effort (cpue) by year class and age over time. Often, the observed cpue at age a + 1 in year y + 1 was greater than in year y at age a . Spearman’s rank correlation of cpue vs. year also demonstrated inconsistencies in the data. The problems related to separating CC and northeast Arctic cod are discussed. |
format |
Text |
author |
Lunde, T. M. Godø, O. R. Rosland, R. |
author_facet |
Lunde, T. M. Godø, O. R. Rosland, R. |
author_sort |
Lunde, T. M. |
title |
Reliability of trawl surveys on cod in Norwegian fjords |
title_short |
Reliability of trawl surveys on cod in Norwegian fjords |
title_full |
Reliability of trawl surveys on cod in Norwegian fjords |
title_fullStr |
Reliability of trawl surveys on cod in Norwegian fjords |
title_full_unstemmed |
Reliability of trawl surveys on cod in Norwegian fjords |
title_sort |
reliability of trawl surveys on cod in norwegian fjords |
publisher |
Oxford University Press |
publishDate |
2008 |
url |
http://icesjms.oxfordjournals.org/cgi/content/short/fsn068v1 https://doi.org/10.1093/icesjms/fsn068 |
long_lat |
ENVELOPE(50.467,50.467,-66.967,-66.967) |
geographic |
Arctic Lunde Norway |
geographic_facet |
Arctic Lunde Norway |
genre |
Arctic cod Arctic Northeast Arctic cod Lunde |
genre_facet |
Arctic cod Arctic Northeast Arctic cod Lunde |
op_relation |
http://icesjms.oxfordjournals.org/cgi/content/short/fsn068v1 http://dx.doi.org/10.1093/icesjms/fsn068 |
op_rights |
Copyright (C) 2008, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer |
op_doi |
https://doi.org/10.1093/icesjms/fsn068 |
container_title |
ICES Journal of Marine Science |
container_volume |
65 |
container_issue |
6 |
container_start_page |
937 |
op_container_end_page |
945 |
_version_ |
1766304302451654656 |