Assessing the South African sardine resource: two stocks rather than one?

dc.contributor.authorde Moor, C L
dc.contributor.authorButterworth, Doug S
dc.date.accessioned2016-08-15T14:11:43Z
dc.date.available2016-08-15T14:11:43Z
dc.date.issued2015
dc.date.updated2016-08-11T11:36:47Z
dc.description.abstractSardine Sardinops sagax distributed off the west and south coasts of South Africa have traditionally been assumed to comprise a single well-mixed stock for assessment and management purposes. New research, however, lends weight to the possibility of two stocks in this region. A precautionary management approach thus needs to consider the impact of management decisions on the hypothesised two individual stocks as well as on the resource as a whole. As a first step in this process, Bayesian assessments of South African sardine are presented, which compare results for the traditional single-stock hypothesis with those that follow from a new two-mixing-stock hypothesis. Recruits from the west stock are assumed to move to and remain part of the south stock in annual pulses of varying size. This movement is estimated to be appreciable, and to take place from a substantially more productive west stock to the south stock. This immigration makes a greater contribution to the south-stock biomass than do years of above-average south-stock recruitment. Importantly, this two-mixing-stock hypothesis is shown to be consistent with the data available. Further alternative sardine stock-structure hypotheses suggested by the most recent data are discussed.en_ZA
dc.identifierhttp://dx.doi.org/http://dx.doi. org/10.2989/1814232X.2015.1009166
dc.identifier.apacitationde Moor, C. L., & Butterworth, D. S. (2015). Assessing the South African sardine resource: two stocks rather than one?. <i>African Journal of Marine Science</i>, http://hdl.handle.net/11427/21258en_ZA
dc.identifier.chicagocitationde Moor, C L, and Doug S Butterworth "Assessing the South African sardine resource: two stocks rather than one?." <i>African Journal of Marine Science</i> (2015) http://hdl.handle.net/11427/21258en_ZA
dc.identifier.citationde Moor, C. L., & Butterworth, D. S. (2015). Assessing the South African sardine resource: two stocks rather than one?. African Journal of Marine Science, 37(1), 41-51.en_ZA
dc.identifier.issn1814-232Xen_ZA
dc.identifier.ris TY - Journal Article AU - de Moor, C L AU - Butterworth, Doug S AB - Sardine Sardinops sagax distributed off the west and south coasts of South Africa have traditionally been assumed to comprise a single well-mixed stock for assessment and management purposes. New research, however, lends weight to the possibility of two stocks in this region. A precautionary management approach thus needs to consider the impact of management decisions on the hypothesised two individual stocks as well as on the resource as a whole. As a first step in this process, Bayesian assessments of South African sardine are presented, which compare results for the traditional single-stock hypothesis with those that follow from a new two-mixing-stock hypothesis. Recruits from the west stock are assumed to move to and remain part of the south stock in annual pulses of varying size. This movement is estimated to be appreciable, and to take place from a substantially more productive west stock to the south stock. This immigration makes a greater contribution to the south-stock biomass than do years of above-average south-stock recruitment. Importantly, this two-mixing-stock hypothesis is shown to be consistent with the data available. Further alternative sardine stock-structure hypotheses suggested by the most recent data are discussed. DA - 2015 DB - OpenUCT DP - University of Cape Town J1 - African Journal of Marine Science LK - https://open.uct.ac.za PB - University of Cape Town PY - 2015 SM - 1814-232X T1 - Assessing the South African sardine resource: two stocks rather than one? TI - Assessing the South African sardine resource: two stocks rather than one? UR - http://hdl.handle.net/11427/21258 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21258
dc.identifier.vancouvercitationde Moor CL, Butterworth DS. Assessing the South African sardine resource: two stocks rather than one?. African Journal of Marine Science. 2015; http://hdl.handle.net/11427/21258.en_ZA
dc.languageengen_ZA
dc.publisherNational Inquiry Services Centreen_ZA
dc.publisher.departmentMarine Resource Assessment and Management Groupen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.sourceAfrican Journal of Marine Scienceen_ZA
dc.source.urihttp://www.tandfonline.com/loi/tams20
dc.subject.otherAssessmen
dc.subject.otherMultiple stocks
dc.subject.otherSardinops sagax
dc.subject.otherStock structure
dc.subject.otherTwo-mixing-stock hypothesis
dc.titleAssessing the South African sardine resource: two stocks rather than one?en_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
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