Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery

 

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dc.contributor.advisor Attwood, Colin en_ZA
dc.contributor.author Rousseau, Meghan en_ZA
dc.date.accessioned 2014-09-22T12:00:27Z
dc.date.available 2014-09-22T12:00:27Z
dc.date.issued 2013 en_ZA
dc.identifier.citation Rousseau, M. 2013. Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/7645
dc.description.abstract In South Africa, linefishing increased in the mid-1800s and eventually reached a peak in the 1980s/90s. A legal linefishery emergency was declared in 2000 in accordance with the Marine Living Resources Act of 1998. This was a large blow for the commercially important industry. Nonetheless, the carpenter stocks had already been overexploited to such a high degree by linefishing, and also as part of trawling bycatch, that even at an effort less than half of the effort that produces a maximum sustainable yield, carpenter stocks were still found below the biomass found at the maximum sustainable yield. In order to explore three different management strategies for the carpenter stock on the offshore Central Agulhas Bank, an agestructured, non-stochastic model was set up. The influences of the following strategies - Total Allowable Catch (TAC), as well as revised minimum size limit and closed season – on a stock found at a dismal 19.2% of carrying capacity, are projected using this model on a monthly time-step. The objectives of this fishery are to achieve a biomass in the final year equal to the biomass found at a maximum sustainable yield (7243 t) and to maximise effort (employment) and catch. The overall recommendation for this stock was a reduction in minimum size limit from 35 cm to 30.48 cm in combination with a flexible TAC starting at 790 t. It is also recommended that even though models are important for fisheries management, no model should be taken in isolation without first considering life history traits and other important information about a stock. en_ZA
dc.language.iso eng en_ZA
dc.title Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery en_ZA
dc.type Bachelor Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Biological Sciences en_ZA
dc.type.qualificationlevel Honours
dc.type.qualificationname BSc en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Rousseau, M. (2013). <i>Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/7645 en_ZA
dc.identifier.chicagocitation Rousseau, Meghan. <i>"Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013. http://hdl.handle.net/11427/7645 en_ZA
dc.identifier.vancouvercitation Rousseau M. Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/7645 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Rousseau, Meghan AB - In South Africa, linefishing increased in the mid-1800s and eventually reached a peak in the 1980s/90s. A legal linefishery emergency was declared in 2000 in accordance with the Marine Living Resources Act of 1998. This was a large blow for the commercially important industry. Nonetheless, the carpenter stocks had already been overexploited to such a high degree by linefishing, and also as part of trawling bycatch, that even at an effort less than half of the effort that produces a maximum sustainable yield, carpenter stocks were still found below the biomass found at the maximum sustainable yield. In order to explore three different management strategies for the carpenter stock on the offshore Central Agulhas Bank, an agestructured, non-stochastic model was set up. The influences of the following strategies - Total Allowable Catch (TAC), as well as revised minimum size limit and closed season – on a stock found at a dismal 19.2% of carrying capacity, are projected using this model on a monthly time-step. The objectives of this fishery are to achieve a biomass in the final year equal to the biomass found at a maximum sustainable yield (7243 t) and to maximise effort (employment) and catch. The overall recommendation for this stock was a reduction in minimum size limit from 35 cm to 30.48 cm in combination with a flexible TAC starting at 790 t. It is also recommended that even though models are important for fisheries management, no model should be taken in isolation without first considering life history traits and other important information about a stock. DA - 2013 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery TI - Modelling the effect of alternative management strategies on the catch and effort in the carpenter (Argyrozona argyrozona) linefishery UR - http://hdl.handle.net/11427/7645 ER - en_ZA


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