Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners
The size of the Icelandic cod stock has been gradually declining since the middle of this century. Recruitment has been poor over an extended period of time and much below the long-term average since 1985. Except for the concurrent decrease in stock size and recruitment during this period, the stock...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Language: | English |
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Canadian Science Publishing
1998
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Online Access: | http://dx.doi.org/10.1139/f98-035 http://www.nrcresearchpress.com/doi/pdf/10.1139/f98-035 |
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crcansciencepubl:10.1139/f98-035 2024-10-13T14:07:23+00:00 Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners Marteinsdottir, Gudrun Thorarinsson, Kristjan 1998 http://dx.doi.org/10.1139/f98-035 http://www.nrcresearchpress.com/doi/pdf/10.1139/f98-035 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 55, issue 6, page 1372-1377 ISSN 0706-652X 1205-7533 journal-article 1998 crcansciencepubl https://doi.org/10.1139/f98-035 2024-09-19T04:09:49Z The size of the Icelandic cod stock has been gradually declining since the middle of this century. Recruitment has been poor over an extended period of time and much below the long-term average since 1985. Except for the concurrent decrease in stock size and recruitment during this period, the stock size - recruitment relationship is weak. This relationship is improved by including the age composition of the spawning stock. Spawning stock age diversity in each year from 1955 to 1992 was estimated with the Shannon index using the number of mature fish in each age group. By including information on age composition, 31% of the total variation in recruitment was accounted for by the model with stock size, age diversity, and the interaction between the two, compared with less than 15% by single factor models of either age diversity or stock size. These results indicate that age diversity is an important component in stock-recruitment models and that one of the management goals for fish species should be to maintain high age diversity in the spawning stocks. Article in Journal/Newspaper Gadus morhua Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 55 6 1372 1377 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
The size of the Icelandic cod stock has been gradually declining since the middle of this century. Recruitment has been poor over an extended period of time and much below the long-term average since 1985. Except for the concurrent decrease in stock size and recruitment during this period, the stock size - recruitment relationship is weak. This relationship is improved by including the age composition of the spawning stock. Spawning stock age diversity in each year from 1955 to 1992 was estimated with the Shannon index using the number of mature fish in each age group. By including information on age composition, 31% of the total variation in recruitment was accounted for by the model with stock size, age diversity, and the interaction between the two, compared with less than 15% by single factor models of either age diversity or stock size. These results indicate that age diversity is an important component in stock-recruitment models and that one of the management goals for fish species should be to maintain high age diversity in the spawning stocks. |
format |
Article in Journal/Newspaper |
author |
Marteinsdottir, Gudrun Thorarinsson, Kristjan |
spellingShingle |
Marteinsdottir, Gudrun Thorarinsson, Kristjan Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners |
author_facet |
Marteinsdottir, Gudrun Thorarinsson, Kristjan |
author_sort |
Marteinsdottir, Gudrun |
title |
Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners |
title_short |
Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners |
title_full |
Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners |
title_fullStr |
Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners |
title_full_unstemmed |
Improving the stock-recruitment relationship in Icelandic cod ( Gadus morhua) by including age diversity of spawners |
title_sort |
improving the stock-recruitment relationship in icelandic cod ( gadus morhua) by including age diversity of spawners |
publisher |
Canadian Science Publishing |
publishDate |
1998 |
url |
http://dx.doi.org/10.1139/f98-035 http://www.nrcresearchpress.com/doi/pdf/10.1139/f98-035 |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 55, issue 6, page 1372-1377 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f98-035 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
55 |
container_issue |
6 |
container_start_page |
1372 |
op_container_end_page |
1377 |
_version_ |
1812813646284193792 |