Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.)
Maturity ogives of the Northeast Arctic cod for the year classes 1932 to 1976 were computed based on age and number of spawning zones in otoliths of cod caught on the spawning grounds at Lofoten. A reduction in the median age at maturity of approximately 2,5 years over the period is indicated. A sim...
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ftimr:oai:imr.brage.unit.no:11250/104511 2023-05-15T14:30:21+02:00 Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.) Jørgensen, Terje 1988 application/pdf http://hdl.handle.net/11250/104511 eng eng ICES ICES CM Documents;1988/G:42 This report is not to be cited without prior reference to the author http://hdl.handle.net/11250/104511 32 s. arctic cod arktisk torsk sexual maturation kjønnsmodning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Working paper 1988 ftimr 2021-09-23T20:15:41Z Maturity ogives of the Northeast Arctic cod for the year classes 1932 to 1976 were computed based on age and number of spawning zones in otoliths of cod caught on the spawning grounds at Lofoten. A reduction in the median age at maturity of approximately 2,5 years over the period is indicated. A similar reduction in mean age of the spawning stock was found. Males generally mature at a lower age than females, but the difference has become smaller over the period studied. The decline in median age at maturity is most marked for the year classes after 1950. A compensatory response to the demographic changes could explain the decline. Genetic changes as a result of selective fishing is also possible, but cannot be evaluated from the present data. Report Arctic cod Arctic Arktis* Gadus morhua Lofoten Northeast Arctic cod Institute for Marine Research: Brage IMR Arctic Lofoten |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
arctic cod arktisk torsk sexual maturation kjønnsmodning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
spellingShingle |
arctic cod arktisk torsk sexual maturation kjønnsmodning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Jørgensen, Terje Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.) |
topic_facet |
arctic cod arktisk torsk sexual maturation kjønnsmodning VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
description |
Maturity ogives of the Northeast Arctic cod for the year classes 1932 to 1976 were computed based on age and number of spawning zones in otoliths of cod caught on the spawning grounds at Lofoten. A reduction in the median age at maturity of approximately 2,5 years over the period is indicated. A similar reduction in mean age of the spawning stock was found. Males generally mature at a lower age than females, but the difference has become smaller over the period studied. The decline in median age at maturity is most marked for the year classes after 1950. A compensatory response to the demographic changes could explain the decline. Genetic changes as a result of selective fishing is also possible, but cannot be evaluated from the present data. |
format |
Report |
author |
Jørgensen, Terje |
author_facet |
Jørgensen, Terje |
author_sort |
Jørgensen, Terje |
title |
Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.) |
title_short |
Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.) |
title_full |
Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.) |
title_fullStr |
Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.) |
title_full_unstemmed |
Long-term changes in age at sexual maturity of the northeast Arctic cod (Gadus morhua L.) |
title_sort |
long-term changes in age at sexual maturity of the northeast arctic cod (gadus morhua l.) |
publisher |
ICES |
publishDate |
1988 |
url |
http://hdl.handle.net/11250/104511 |
geographic |
Arctic Lofoten |
geographic_facet |
Arctic Lofoten |
genre |
Arctic cod Arctic Arktis* Gadus morhua Lofoten Northeast Arctic cod |
genre_facet |
Arctic cod Arctic Arktis* Gadus morhua Lofoten Northeast Arctic cod |
op_source |
32 s. |
op_relation |
ICES CM Documents;1988/G:42 This report is not to be cited without prior reference to the author http://hdl.handle.net/11250/104511 |
_version_ |
1766304198538821632 |