Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size?
This study presents an investigation of the relationship between stock size of North Sea cod ( Gadus morhua ) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a new model allowing both density-dependent changes in catchability and bias in the asse...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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2008
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Online Access: | http://dx.doi.org/10.1139/f08-086 http://www.nrcresearchpress.com/doi/full-xml/10.1139/F08-086 http://www.nrcresearchpress.com/doi/pdf/10.1139/F08-086 |
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crcansciencepubl:10.1139/f08-086 2023-12-17T10:30:22+01:00 Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size? Rindorf, Anna Andersen, Bo Sølgaard 2008 http://dx.doi.org/10.1139/f08-086 http://www.nrcresearchpress.com/doi/full-xml/10.1139/F08-086 http://www.nrcresearchpress.com/doi/pdf/10.1139/F08-086 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 65, issue 9, page 1800-1813 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2008 crcansciencepubl https://doi.org/10.1139/f08-086 2023-11-19T13:38:34Z This study presents an investigation of the relationship between stock size of North Sea cod ( Gadus morhua ) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a new model allowing both density-dependent changes in catchability and bias in the assessment biomass estimates. Catchability in fisheries targeting a mixed species composition either remained constant or decreased with decreasing stock size, whereas catchability in targeted cod fisheries increased with decreasing stock size. However, even in the cases where catchability increased, the change was insufficient to compensate for the decrease in stock size, and catch rates of all fleets decreased. Two factors that could lead to nonconstant catchability were investigated: (i) the presence of a decoupling between stock size and density in high-density areas and (ii) the presence of concurrent shifts in the spatial distribution of the cod stock and the cod fishery. No evidence of the former was found, but there was a northern shift in the spatial distribution of both effort and the cod stock. Article in Journal/Newspaper Gadus morhua Canadian Science Publishing (via Crossref) Canadian Journal of Fisheries and Aquatic Sciences 65 9 1800 1813 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Rindorf, Anna Andersen, Bo Sølgaard Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size? |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
This study presents an investigation of the relationship between stock size of North Sea cod ( Gadus morhua ) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a new model allowing both density-dependent changes in catchability and bias in the assessment biomass estimates. Catchability in fisheries targeting a mixed species composition either remained constant or decreased with decreasing stock size, whereas catchability in targeted cod fisheries increased with decreasing stock size. However, even in the cases where catchability increased, the change was insufficient to compensate for the decrease in stock size, and catch rates of all fleets decreased. Two factors that could lead to nonconstant catchability were investigated: (i) the presence of a decoupling between stock size and density in high-density areas and (ii) the presence of concurrent shifts in the spatial distribution of the cod stock and the cod fishery. No evidence of the former was found, but there was a northern shift in the spatial distribution of both effort and the cod stock. |
format |
Article in Journal/Newspaper |
author |
Rindorf, Anna Andersen, Bo Sølgaard |
author_facet |
Rindorf, Anna Andersen, Bo Sølgaard |
author_sort |
Rindorf, Anna |
title |
Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size? |
title_short |
Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size? |
title_full |
Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size? |
title_fullStr |
Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size? |
title_full_unstemmed |
Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size? |
title_sort |
do north sea cod (gadus morhua) fisheries maintain high catch rates at low stock size? |
publisher |
Canadian Science Publishing |
publishDate |
2008 |
url |
http://dx.doi.org/10.1139/f08-086 http://www.nrcresearchpress.com/doi/full-xml/10.1139/F08-086 http://www.nrcresearchpress.com/doi/pdf/10.1139/F08-086 |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 65, issue 9, page 1800-1813 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f08-086 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
65 |
container_issue |
9 |
container_start_page |
1800 |
op_container_end_page |
1813 |
_version_ |
1785583316284473344 |