A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters
Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described by n...
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ftdtupubl:oai:pure.atira.dk:publications/6dff001c-9945-4263-bcb6-364536b2011d 2023-10-01T03:54:32+02:00 A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters Hovgård, Holger 1996 https://orbit.dtu.dk/en/publications/6dff001c-9945-4263-bcb6-364536b2011d eng eng info:eu-repo/semantics/restrictedAccess Hovgård , H 1996 , ' A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters ' , Canadian Journal of Fisheries and Aquatic Sciences , vol. 53 , no. 5 , pp. 1007-1013 . article 1996 ftdtupubl 2023-09-06T22:56:10Z Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described by normal distributions and could be related to mesh size in accordance with the principle of geometrical similarity. In the second step the selection parameters were estimated by a nonlinear least squares fit. The model also estimated the relative efficiency of the two capture processes and the fishing powers of different netting sections. Gilling was about three times as efficient as maxillae catching and fishing power could be related to the ratio of twine diameter to mesh size. It is proposed that information on how fish are caught should be included when modelling gill-net selectivity, as lack of such data may lead to the formulation of unrealistic selection models. Article in Journal/Newspaper atlantic cod Gadus morhua Greenland Technical University of Denmark: DTU Orbit Greenland |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
description |
Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described by normal distributions and could be related to mesh size in accordance with the principle of geometrical similarity. In the second step the selection parameters were estimated by a nonlinear least squares fit. The model also estimated the relative efficiency of the two capture processes and the fishing powers of different netting sections. Gilling was about three times as efficient as maxillae catching and fishing power could be related to the ratio of twine diameter to mesh size. It is proposed that information on how fish are caught should be included when modelling gill-net selectivity, as lack of such data may lead to the formulation of unrealistic selection models. |
format |
Article in Journal/Newspaper |
author |
Hovgård, Holger |
spellingShingle |
Hovgård, Holger A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters |
author_facet |
Hovgård, Holger |
author_sort |
Hovgård, Holger |
title |
A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters |
title_short |
A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters |
title_full |
A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters |
title_fullStr |
A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters |
title_full_unstemmed |
A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters |
title_sort |
two-step approach to estimating selectivity and fishing power of research gill nets used in greenland waters |
publishDate |
1996 |
url |
https://orbit.dtu.dk/en/publications/6dff001c-9945-4263-bcb6-364536b2011d |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
atlantic cod Gadus morhua Greenland |
genre_facet |
atlantic cod Gadus morhua Greenland |
op_source |
Hovgård , H 1996 , ' A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters ' , Canadian Journal of Fisheries and Aquatic Sciences , vol. 53 , no. 5 , pp. 1007-1013 . |
op_rights |
info:eu-repo/semantics/restrictedAccess |
_version_ |
1778522303115558912 |