A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus)

 

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dc.contributor.advisor Field, John G en_ZA
dc.contributor.advisor Newman , G G en_ZA
dc.contributor.author Mertens, Robert George Stephen en_ZA
dc.date.accessioned 2015-03-16T10:30:35Z
dc.date.available 2015-03-16T10:30:35Z
dc.date.issued 1978 en_ZA
dc.identifier.citation Mertens, R. 1978. A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus). University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/12613
dc.description Includes bibliographical references (leaves 63-68). en_ZA
dc.description.abstract Catch and effort statistics for the Cape hakes (Merluccius capensis and M. paradoxus) have indicated a substantial decrease in the stock size over the period 1955-74; consequently, a catch projection model was designed to investigate the hake population. Where appropriate, available data have been included in the model; however, some further research was required: 1. The monthly pattern of availability for 1974-76 was examined using South African data; it was found to be similar to that reported for earlier years, and the later figures were used. 2. Assuming that selection curves for different mesh sizes are identical except for their position on the X-axis, a method to calculate selection values for combinations of mesh size and fish length has been outlined, and used with data presented by Bohl et al. (1971). 3. An investigation was made of two methods of estimating natural mortality (M), utilizing the results of Virtual Population Analysis (V.P.A.). In both cases the criteria used to judge M were found to be insensitive, and therefore neither can be used. 4. The stock estimates obtained using V.P.A. were applied to two stock/recruit curves. The goodness of fit in both cases was poor, and nearly identical. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Zoology en_ZA
dc.title A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus) en_ZA
dc.type Master 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 Masters
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Mertens, R. G. S. (1978). <i>A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus)</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/12613 en_ZA
dc.identifier.chicagocitation Mertens, Robert George Stephen. <i>"A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus)."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1978. http://hdl.handle.net/11427/12613 en_ZA
dc.identifier.vancouvercitation Mertens RGS. A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus). [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1978 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/12613 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Mertens, Robert George Stephen AB - Catch and effort statistics for the Cape hakes (Merluccius capensis and M. paradoxus) have indicated a substantial decrease in the stock size over the period 1955-74; consequently, a catch projection model was designed to investigate the hake population. Where appropriate, available data have been included in the model; however, some further research was required: 1. The monthly pattern of availability for 1974-76 was examined using South African data; it was found to be similar to that reported for earlier years, and the later figures were used. 2. Assuming that selection curves for different mesh sizes are identical except for their position on the X-axis, a method to calculate selection values for combinations of mesh size and fish length has been outlined, and used with data presented by Bohl et al. (1971). 3. An investigation was made of two methods of estimating natural mortality (M), utilizing the results of Virtual Population Analysis (V.P.A.). In both cases the criteria used to judge M were found to be insensitive, and therefore neither can be used. 4. The stock estimates obtained using V.P.A. were applied to two stock/recruit curves. The goodness of fit in both cases was poor, and nearly identical. DA - 1978 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1978 T1 - A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus) TI - A computer simulation of the population dynamics of the Cape hakes (Merluccius capensis and M. paradoxus) UR - http://hdl.handle.net/11427/12613 ER - en_ZA


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