Scale damage and survival of cod and haddock escaping from a demersal trawl
Cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus L.) escaping through the meshes of a cod-end (135 mm diamond meshes) or through a metal grid sorting device mounted in the foremost part of the cod-end, were withheld in cages (2x2x5m) covering the cod-end during trawling. The scale loss of...
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ftimr:oai:imr.brage.unit.no:11250/104864 2023-05-15T16:19:10+02:00 Scale damage and survival of cod and haddock escaping from a demersal trawl Soldal, Aud Vold Isaksen, Bjørnar Marteinsson, Jon Einar Engås, Arill 1991 application/pdf http://hdl.handle.net/11250/104864 eng eng ICES ICES CM Documents;1991/B:44 This report is not to be cited without prior reference to the authors http://hdl.handle.net/11250/104864 12 s. cod torsk haddock hyse demersal fish bunnfisk trawl trål VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Working paper 1991 ftimr 2021-09-23T20:14:53Z Cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus L.) escaping through the meshes of a cod-end (135 mm diamond meshes) or through a metal grid sorting device mounted in the foremost part of the cod-end, were withheld in cages (2x2x5m) covering the cod-end during trawling. The scale loss of the escaped fish was examined and compared to that of cod and haddock from a control group. On average, less than 1% of the total body surface of cod was injured, while haddock, particularly those smaller than 40 cm, showed substantial scale loss. Cages containing escaped fish were released from the trawl by means of an acoustic releaser and kept for observation (UTV) at sea bottom for 12 to 16 days. No mortality was found for cod, and the mortality of mesh and grid selected haddock was less than 10%. Methodological problems that may have lead to errors in the mortality estimates are discussed. Report Gadus morhua Institute for Marine Research: Brage IMR |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
cod torsk haddock hyse demersal fish bunnfisk trawl trål VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
spellingShingle |
cod torsk haddock hyse demersal fish bunnfisk trawl trål VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Soldal, Aud Vold Isaksen, Bjørnar Marteinsson, Jon Einar Engås, Arill Scale damage and survival of cod and haddock escaping from a demersal trawl |
topic_facet |
cod torsk haddock hyse demersal fish bunnfisk trawl trål VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ethology: 485 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fisheries technology: 924 VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
description |
Cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus L.) escaping through the meshes of a cod-end (135 mm diamond meshes) or through a metal grid sorting device mounted in the foremost part of the cod-end, were withheld in cages (2x2x5m) covering the cod-end during trawling. The scale loss of the escaped fish was examined and compared to that of cod and haddock from a control group. On average, less than 1% of the total body surface of cod was injured, while haddock, particularly those smaller than 40 cm, showed substantial scale loss. Cages containing escaped fish were released from the trawl by means of an acoustic releaser and kept for observation (UTV) at sea bottom for 12 to 16 days. No mortality was found for cod, and the mortality of mesh and grid selected haddock was less than 10%. Methodological problems that may have lead to errors in the mortality estimates are discussed. |
format |
Report |
author |
Soldal, Aud Vold Isaksen, Bjørnar Marteinsson, Jon Einar Engås, Arill |
author_facet |
Soldal, Aud Vold Isaksen, Bjørnar Marteinsson, Jon Einar Engås, Arill |
author_sort |
Soldal, Aud Vold |
title |
Scale damage and survival of cod and haddock escaping from a demersal trawl |
title_short |
Scale damage and survival of cod and haddock escaping from a demersal trawl |
title_full |
Scale damage and survival of cod and haddock escaping from a demersal trawl |
title_fullStr |
Scale damage and survival of cod and haddock escaping from a demersal trawl |
title_full_unstemmed |
Scale damage and survival of cod and haddock escaping from a demersal trawl |
title_sort |
scale damage and survival of cod and haddock escaping from a demersal trawl |
publisher |
ICES |
publishDate |
1991 |
url |
http://hdl.handle.net/11250/104864 |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
12 s. |
op_relation |
ICES CM Documents;1991/B:44 This report is not to be cited without prior reference to the authors http://hdl.handle.net/11250/104864 |
_version_ |
1766005510961627136 |