Modelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas bank

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dc.contributor.advisorField, John Gen_ZA
dc.contributor.advisorMoloney, Coleenen_ZA
dc.contributor.advisorLeslie, Roben_ZA
dc.contributor.authorJayiya, Terence Phindaen_ZA
dc.date.accessioned2014-08-13T14:03:30Z
dc.date.available2014-08-13T14:03:30Z
dc.date.issued2001en_ZA
dc.descriptionBibliograpy: leaves 87-101.en_ZA
dc.description.abstractA Geographic Information System (GIS) is used to elucidiate vertical and horizontal patterns of distribution of Merluccius capensis on the inshore south coast (20°-27°E) of South Africa. Catch data used to compare the size distribution in catches made by commercial trawls and longlines off the South Coast (20°E). Results show that M.capensis size increases with depth and that the distribution of fish < 30 cm is mostly west of 23° E with isolated pockets east of that region. No seasonal differences were found in the distribution of this species. Spatial mapping of survey trawl and longline grounds of the Agulhas bank whereas longlines operate over rocky areas. Size comparisons of the catches of the two fishing methods reveal that longlines catch very few fish that are < 60 cm whereas trawl cataches are dominated by M. capensis of length < 60 cm. Analyses also revealed sex compostion in longline cataches to be different to that of trawls. All these results are discussed in relation to the ecology of M. capensis and the areas where data come from. Using size selectivity properties, the potential impacts of longlining and commercial trawling on the South Coast M. capensis (east of 20° E) are modelled with a yield per recruit and spawner biomass per recruit model. First, the age-specific selectivity vectors of the two fleets are estimated from catch data (length frequencies).en_ZA
dc.identifier.apacitationJayiya, T. P. (2001). <i>Modelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas bank</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/6105en_ZA
dc.identifier.chicagocitationJayiya, Terence Phinda. <i>"Modelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas bank."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2001. http://hdl.handle.net/11427/6105en_ZA
dc.identifier.citationJayiya, T. 2001. Modelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas bank. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Jayiya, Terence Phinda AB - A Geographic Information System (GIS) is used to elucidiate vertical and horizontal patterns of distribution of Merluccius capensis on the inshore south coast (20°-27°E) of South Africa. Catch data used to compare the size distribution in catches made by commercial trawls and longlines off the South Coast (20°E). Results show that M.capensis size increases with depth and that the distribution of fish < 30 cm is mostly west of 23° E with isolated pockets east of that region. No seasonal differences were found in the distribution of this species. Spatial mapping of survey trawl and longline grounds of the Agulhas bank whereas longlines operate over rocky areas. Size comparisons of the catches of the two fishing methods reveal that longlines catch very few fish that are < 60 cm whereas trawl cataches are dominated by M. capensis of length < 60 cm. Analyses also revealed sex compostion in longline cataches to be different to that of trawls. All these results are discussed in relation to the ecology of M. capensis and the areas where data come from. Using size selectivity properties, the potential impacts of longlining and commercial trawling on the South Coast M. capensis (east of 20° E) are modelled with a yield per recruit and spawner biomass per recruit model. First, the age-specific selectivity vectors of the two fleets are estimated from catch data (length frequencies). DA - 2001 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2001 T1 - Modelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas bank TI - Modelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas bank UR - http://hdl.handle.net/11427/6105 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/6105
dc.identifier.vancouvercitationJayiya TP. Modelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas bank. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2001 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/6105en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherZoologyen_ZA
dc.titleModelling the relative impacts of trawling and longlining on Cape hake Merluccius capensis on the inshore Agulhas banken_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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