Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic
Analysis of 46 yr of research trawl survey data from seven regions in the Northwest Atlantic (Newfoundland and Labrador) indicated that older individuals of Atlantic cod, Gadus morhua, of both sexes initiated and completed spawning later, and spawned for a greater length of time, than younger indivi...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Language: | English |
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Canadian Science Publishing
1993
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Online Access: | http://dx.doi.org/10.1139/f93-271 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-271 |
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crcansciencepubl:10.1139/f93-271 2024-09-15T17:55:22+00:00 Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic Hutchings, Jeffrey A. Myers, Ransom A. 1993 http://dx.doi.org/10.1139/f93-271 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-271 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 50, issue 11, page 2468-2474 ISSN 0706-652X 1205-7533 journal-article 1993 crcansciencepubl https://doi.org/10.1139/f93-271 2024-08-01T04:10:01Z Analysis of 46 yr of research trawl survey data from seven regions in the Northwest Atlantic (Newfoundland and Labrador) indicated that older individuals of Atlantic cod, Gadus morhua, of both sexes initiated and completed spawning later, and spawned for a greater length of time, than younger individuals. Within regions, males were in spawning condition for longer periods than females. Among regions, spawning duration of males (age = 11 yr) averaged 43.5 ± 13.6 d and was significantly longer than that of females (age = 11 yr; 25.2 ± 8.4 d). The strong association between age and time of spawning provides empirical evidence of size-specific, assortative mating in cod. The decline in recruitment of cod in NAFO Division 2J3KL since 1962 is associated with a dramatic reduction in the fecundity contribution of older (15–20 yr) relative to younger (7–9 yr) individuals. Our results indicate that this increase in proportional abundance of younger individuals should be concomitant with a decline in the duration of spawning time, reducing the probability that larval emergence will match peak abundances of zooplankton. Thus, age dependence of maturation and spawning times provides a mechanism by which size-selective mortality against larger, older individuals can increase variability in recruitment in Atlantic cod. Article in Journal/Newspaper atlantic cod Gadus morhua Newfoundland Northwest Atlantic Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 50 11 2468 2474 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
description |
Analysis of 46 yr of research trawl survey data from seven regions in the Northwest Atlantic (Newfoundland and Labrador) indicated that older individuals of Atlantic cod, Gadus morhua, of both sexes initiated and completed spawning later, and spawned for a greater length of time, than younger individuals. Within regions, males were in spawning condition for longer periods than females. Among regions, spawning duration of males (age = 11 yr) averaged 43.5 ± 13.6 d and was significantly longer than that of females (age = 11 yr; 25.2 ± 8.4 d). The strong association between age and time of spawning provides empirical evidence of size-specific, assortative mating in cod. The decline in recruitment of cod in NAFO Division 2J3KL since 1962 is associated with a dramatic reduction in the fecundity contribution of older (15–20 yr) relative to younger (7–9 yr) individuals. Our results indicate that this increase in proportional abundance of younger individuals should be concomitant with a decline in the duration of spawning time, reducing the probability that larval emergence will match peak abundances of zooplankton. Thus, age dependence of maturation and spawning times provides a mechanism by which size-selective mortality against larger, older individuals can increase variability in recruitment in Atlantic cod. |
format |
Article in Journal/Newspaper |
author |
Hutchings, Jeffrey A. Myers, Ransom A. |
spellingShingle |
Hutchings, Jeffrey A. Myers, Ransom A. Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic |
author_facet |
Hutchings, Jeffrey A. Myers, Ransom A. |
author_sort |
Hutchings, Jeffrey A. |
title |
Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic |
title_short |
Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic |
title_full |
Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic |
title_fullStr |
Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic |
title_full_unstemmed |
Effect of Age on the Seasonality of Maturation and Spawning of Atlantic Cod, Gadus morhua, in the Northwest Atlantic |
title_sort |
effect of age on the seasonality of maturation and spawning of atlantic cod, gadus morhua, in the northwest atlantic |
publisher |
Canadian Science Publishing |
publishDate |
1993 |
url |
http://dx.doi.org/10.1139/f93-271 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-271 |
genre |
atlantic cod Gadus morhua Newfoundland Northwest Atlantic |
genre_facet |
atlantic cod Gadus morhua Newfoundland Northwest Atlantic |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 50, issue 11, page 2468-2474 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f93-271 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
50 |
container_issue |
11 |
container_start_page |
2468 |
op_container_end_page |
2474 |
_version_ |
1810431659916394496 |