A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity
The status of the toothfish resource in the Prince Edward Islands region is unclear because CPUE data suggest considerable depletion, whereas catch-at-length information indicates that past catches have had relatively little impact on abundance. A Management Procedure (MP) approach is proposed to pr...
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Online Access: | http://hdl.handle.net/11427/36830 https://open.uct.ac.za/bitstream/11427/36830/1/02brandao-butterworth.pdf |
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ftunivcapetownir:oai:localhost:11427/36830 2023-05-15T18:03:27+02:00 A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity A, Brandão D S, Butterworth 2009 application/pdf http://hdl.handle.net/11427/36830 https://open.uct.ac.za/bitstream/11427/36830/1/02brandao-butterworth.pdf en eng Faculty of Science Marine Resource Assessment and Management Group http://hdl.handle.net/11427/36830 https://open.uct.ac.za/bitstream/11427/36830/1/02brandao-butterworth.pdf CCAMLR Science 16 2009 33 - 69 Journal Article 2009 ftunivcapetownir 2022-10-06T23:12:32Z The status of the toothfish resource in the Prince Edward Islands region is unclear because CPUE data suggest considerable depletion, whereas catch-at-length information indicates that past catches have had relatively little impact on abundance. A Management Procedure (MP) approach is proposed to provide a sound scientific basis to recommend future TACs in the face of this appreciable uncertainty. Four Operating Models (OMs) reflecting ‘Optimistic’, ‘Intermediate’, ‘Less Pessimistic’ and a ‘Pessimistic’ current status for the resource are developed which take account of the different selectivities of past longline and pot fisheries. These OMs are used for trials of a candidate generic MP which could provide future TAC recommendations for this resource. The MP uses two data sources: the recent trend in longline CPUE and the mean length of the catches made. An MP with control parameter values specified is proposed for implementation based on the results of the trials. Given the importance of an adequate catch rate for the economic viability of the fishery, the choice of control parameter values focused primarily on a reasonable probability of securing a catch rate increase, whatever the current resource status. MP performance is reasonably robust across a range of sensitivity tests, although it does deteriorate in conservation terms if the stock-recruitment curve steepness h is low. These tests also indicate that monitoring of future catch-at-length information would be necessary to guard against a change in selectivity towards greater catches of older fish. Article in Journal/Newspaper Prince Edward Islands University of Cape Town: OpenUCT Tac ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
institution |
Open Polar |
collection |
University of Cape Town: OpenUCT |
op_collection_id |
ftunivcapetownir |
language |
English |
description |
The status of the toothfish resource in the Prince Edward Islands region is unclear because CPUE data suggest considerable depletion, whereas catch-at-length information indicates that past catches have had relatively little impact on abundance. A Management Procedure (MP) approach is proposed to provide a sound scientific basis to recommend future TACs in the face of this appreciable uncertainty. Four Operating Models (OMs) reflecting ‘Optimistic’, ‘Intermediate’, ‘Less Pessimistic’ and a ‘Pessimistic’ current status for the resource are developed which take account of the different selectivities of past longline and pot fisheries. These OMs are used for trials of a candidate generic MP which could provide future TAC recommendations for this resource. The MP uses two data sources: the recent trend in longline CPUE and the mean length of the catches made. An MP with control parameter values specified is proposed for implementation based on the results of the trials. Given the importance of an adequate catch rate for the economic viability of the fishery, the choice of control parameter values focused primarily on a reasonable probability of securing a catch rate increase, whatever the current resource status. MP performance is reasonably robust across a range of sensitivity tests, although it does deteriorate in conservation terms if the stock-recruitment curve steepness h is low. These tests also indicate that monitoring of future catch-at-length information would be necessary to guard against a change in selectivity towards greater catches of older fish. |
format |
Article in Journal/Newspaper |
author |
A, Brandão D S, Butterworth |
spellingShingle |
A, Brandão D S, Butterworth A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity |
author_facet |
A, Brandão D S, Butterworth |
author_sort |
A, Brandão |
title |
A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity |
title_short |
A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity |
title_full |
A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity |
title_fullStr |
A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity |
title_full_unstemmed |
A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity |
title_sort |
proposed management procedure for the toothfish (dissostichus eleginoides) resource in the prince edward islands vicinity |
publisher |
Faculty of Science |
publishDate |
2009 |
url |
http://hdl.handle.net/11427/36830 https://open.uct.ac.za/bitstream/11427/36830/1/02brandao-butterworth.pdf |
long_lat |
ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
geographic |
Tac |
geographic_facet |
Tac |
genre |
Prince Edward Islands |
genre_facet |
Prince Edward Islands |
op_source |
CCAMLR Science 16 2009 33 - 69 |
op_relation |
http://hdl.handle.net/11427/36830 https://open.uct.ac.za/bitstream/11427/36830/1/02brandao-butterworth.pdf |
_version_ |
1766174302551408640 |