Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery
During 1997, considerable scientific differences arose about the status of the Namibian hake (Merluccius capensis and M. paradoxus) resource, and as to whether the hake Total Allowable Catch (TAC) should be substantially decreased or increased. These differences revolved primarily around whether or...
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ftjafricanj:oai:ojs.ajol.info:article/33364 2023-05-15T16:18:27+02:00 Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery Butterworth, DS Geromont, HF 2006-10-23 application/pdf http://www.ajol.info/index.php/ajms/article/view/33364 eng eng NISC http://www.ajol.info/index.php/ajms/article/view/33364/24063 http://www.ajol.info/index.php/ajms/article/view/33364 Copyright for articles published in this journal is retained by the publisher. African Journal of Marine Science; Vol 23 (2001); 357-374 1814-232X abundance Cape hake Management Procedure Namibia performance surveys trade-off info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article 2006 ftjafricanj 2017-03-05T06:40:41Z During 1997, considerable scientific differences arose about the status of the Namibian hake (Merluccius capensis and M. paradoxus) resource, and as to whether the hake Total Allowable Catch (TAC) should be substantially decreased or increased. These differences revolved primarily around whether or not abundance estimates from the swept-area trawl surveys by the Norwegian research vessel Dr Fridtjof Nansen should be considered as reliable measures of biomass in absolute (as distinct from relative) terms. The paper relates the computations underlying the Interim Management Procedure (IMP) approach that was put forward at that time as a basis to resolve this impasse. The anticipated performance, in terms of catch and risk of resource depletion, of a number of simple candidate IMPs for the Namibian hake resource is evaluated. The IMPs depend on two parameters, whose values are to be chosen by decision-makers, and adjust the TAC up or down from one year to the next according to whether trends in recent commercial catch rate and survey indices of abundance are positive or negative. Performances are evaluated across the then current wide range argued for resource abundance and status. Trade-offs in performance across the candidates considered are discussed. One of the candidates was subsequently selected by a joint meeting of scientists, industry and Ministry officials in February 1998 and served as the basis for scientific recommendations for the TAC for the hake resource for the following three years. Keywords: abundance, Cape hake, Management Procedure, Namibia, performance, surveys, trade-offAfrican Journal of Marine Science 2001, 23: 357–374 Article in Journal/Newspaper Fridtjof Nansen AJOL - African Journals Online Fridtjof ENVELOPE(-56.717,-56.717,-63.567,-63.567) Hake ENVELOPE(15.612,15.612,66.797,66.797) Tac ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
institution |
Open Polar |
collection |
AJOL - African Journals Online |
op_collection_id |
ftjafricanj |
language |
English |
topic |
abundance Cape hake Management Procedure Namibia performance surveys trade-off |
spellingShingle |
abundance Cape hake Management Procedure Namibia performance surveys trade-off Butterworth, DS Geromont, HF Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery |
topic_facet |
abundance Cape hake Management Procedure Namibia performance surveys trade-off |
description |
During 1997, considerable scientific differences arose about the status of the Namibian hake (Merluccius capensis and M. paradoxus) resource, and as to whether the hake Total Allowable Catch (TAC) should be substantially decreased or increased. These differences revolved primarily around whether or not abundance estimates from the swept-area trawl surveys by the Norwegian research vessel Dr Fridtjof Nansen should be considered as reliable measures of biomass in absolute (as distinct from relative) terms. The paper relates the computations underlying the Interim Management Procedure (IMP) approach that was put forward at that time as a basis to resolve this impasse. The anticipated performance, in terms of catch and risk of resource depletion, of a number of simple candidate IMPs for the Namibian hake resource is evaluated. The IMPs depend on two parameters, whose values are to be chosen by decision-makers, and adjust the TAC up or down from one year to the next according to whether trends in recent commercial catch rate and survey indices of abundance are positive or negative. Performances are evaluated across the then current wide range argued for resource abundance and status. Trade-offs in performance across the candidates considered are discussed. One of the candidates was subsequently selected by a joint meeting of scientists, industry and Ministry officials in February 1998 and served as the basis for scientific recommendations for the TAC for the hake resource for the following three years. Keywords: abundance, Cape hake, Management Procedure, Namibia, performance, surveys, trade-offAfrican Journal of Marine Science 2001, 23: 357–374 |
format |
Article in Journal/Newspaper |
author |
Butterworth, DS Geromont, HF |
author_facet |
Butterworth, DS Geromont, HF |
author_sort |
Butterworth, DS |
title |
Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery |
title_short |
Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery |
title_full |
Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery |
title_fullStr |
Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery |
title_full_unstemmed |
Evaluation of a class of possible simple interim management procedures for the Namibian hake fishery |
title_sort |
evaluation of a class of possible simple interim management procedures for the namibian hake fishery |
publisher |
NISC |
publishDate |
2006 |
url |
http://www.ajol.info/index.php/ajms/article/view/33364 |
long_lat |
ENVELOPE(-56.717,-56.717,-63.567,-63.567) ENVELOPE(15.612,15.612,66.797,66.797) ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
geographic |
Fridtjof Hake Tac |
geographic_facet |
Fridtjof Hake Tac |
genre |
Fridtjof Nansen |
genre_facet |
Fridtjof Nansen |
op_source |
African Journal of Marine Science; Vol 23 (2001); 357-374 1814-232X |
op_relation |
http://www.ajol.info/index.php/ajms/article/view/33364/24063 http://www.ajol.info/index.php/ajms/article/view/33364 |
op_rights |
Copyright for articles published in this journal is retained by the publisher. |
_version_ |
1766004624326656000 |