Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984
In November - December 1984, 8,038 seven to eight month old pond or basin reared cod fry were tagged and released in Heimarkspollen, a landlocked fjord in western Norway. The aim of this study was to investigate whether recapture rate (survival) was influenced by tagging method, release method or si...
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ftimr:oai:imr.brage.unit.no:11250/104322 2023-05-15T16:19:14+02:00 Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984 Svåsand, Terje Kristiansen, Tore S. Næss, Harald 1987 application/pdf http://hdl.handle.net/11250/104322 eng eng ICES ICES CM Documents;1987/F:25 This report is not to be cited without prior reference to the authors http://hdl.handle.net/11250/104322 16 s. tagging merking recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 Working paper 1987 ftimr 2021-09-23T20:15:27Z In November - December 1984, 8,038 seven to eight month old pond or basin reared cod fry were tagged and released in Heimarkspollen, a landlocked fjord in western Norway. The aim of this study was to investigate whether recapture rate (survival) was influenced by tagging method, release method or size at release, and to study the growth pattern of the different size groups after release. The juveniles were graded in four size groups and tagged with either Internal Steal Tags or Floy Anchor Tags. The fry were released in shallow nearshore waters one by one or in small groups. Tag return to 1 June 1987 from fishing surveys and recaptures reported by local fishermen were 7.6 %. There were no significant differences in percentage recaptured between cod tagged with Internal Steal Tags and Floy Anchor Tags or between single and group released fry. The recapture rates increased with increasing size at release, which indicated size dependent mortality. There was a tendency of growth compensation in the smallest size groups, and for recaptured cod older than two years there was no significant difference in mean length at age between the size groups. Report Gadus morhua Institute for Marine Research: Brage IMR Norway |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
tagging merking recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 |
spellingShingle |
tagging merking recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 Svåsand, Terje Kristiansen, Tore S. Næss, Harald Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984 |
topic_facet |
tagging merking recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925 |
description |
In November - December 1984, 8,038 seven to eight month old pond or basin reared cod fry were tagged and released in Heimarkspollen, a landlocked fjord in western Norway. The aim of this study was to investigate whether recapture rate (survival) was influenced by tagging method, release method or size at release, and to study the growth pattern of the different size groups after release. The juveniles were graded in four size groups and tagged with either Internal Steal Tags or Floy Anchor Tags. The fry were released in shallow nearshore waters one by one or in small groups. Tag return to 1 June 1987 from fishing surveys and recaptures reported by local fishermen were 7.6 %. There were no significant differences in percentage recaptured between cod tagged with Internal Steal Tags and Floy Anchor Tags or between single and group released fry. The recapture rates increased with increasing size at release, which indicated size dependent mortality. There was a tendency of growth compensation in the smallest size groups, and for recaptured cod older than two years there was no significant difference in mean length at age between the size groups. |
format |
Report |
author |
Svåsand, Terje Kristiansen, Tore S. Næss, Harald |
author_facet |
Svåsand, Terje Kristiansen, Tore S. Næss, Harald |
author_sort |
Svåsand, Terje |
title |
Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984 |
title_short |
Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984 |
title_full |
Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984 |
title_fullStr |
Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984 |
title_full_unstemmed |
Tagging experiments on artificially reared 0-group coastal cod (Gadus morhua L.) in western Norway - results from the releases in 1984 |
title_sort |
tagging experiments on artificially reared 0-group coastal cod (gadus morhua l.) in western norway - results from the releases in 1984 |
publisher |
ICES |
publishDate |
1987 |
url |
http://hdl.handle.net/11250/104322 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
16 s. |
op_relation |
ICES CM Documents;1987/F:25 This report is not to be cited without prior reference to the authors http://hdl.handle.net/11250/104322 |
_version_ |
1766005587420643328 |