Assessment of the South African anchovy resource using data from 1984 - 2015: results at the posterior mode

dc.contributor.authorde Moor, Carryn L
dc.date.accessioned2017-02-20T06:19:11Z
dc.date.available2017-02-20T06:19:11Z
dc.date.issued2016-10
dc.description.abstractThe operating model (OM) for the South African anchovy resource has been updated from that used to develop OMP-14 given four more years of data. The model has been altered from previous assessments to now fit directly to length frequency data, removing the earlier need for estimates of proportions of anchovy-at-age 1 during the annual November hydroacoustic survey. A Beverton Holt stock recruitment relationship is used for the base case. Time-invariant natural mortality is assumed to be 1.2year^(-1) for both juvenile and adult natural mortality as before; this provides a better fit to the data than other options considered. The resource abundance is estimated to be near the historical (1984-2014) average, with a total biomass of 3.3 million tons in November 2015. Recruitment reflects three major peaks over the past 20 years, although the lowest points in these fluctuations were still large, being similar to the maximum recruitment prior to 2000.en_ZA
dc.identifier.apacitationde Moor, C. L. (2016). <i>Assessment of the South African anchovy resource using data from 1984 - 2015: results at the posterior mode</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group. Retrieved from http://hdl.handle.net/11427/23975en_ZA
dc.identifier.chicagocitationde Moor, Carryn L <i>Assessment of the South African anchovy resource using data from 1984 - 2015: results at the posterior mode.</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group, 2016. http://hdl.handle.net/11427/23975en_ZA
dc.identifier.citationde Moor, C.L. 2016. Assessment of the South African anchovy resource using data from 1984 – 2015: results at the posterior mode. DAFF Branch Fisheries document. FISHERIES/2016/OCT/SWG-PEL/46: 41pp.en_ZA
dc.identifier.ris TY - Working Paper AU - de Moor, Carryn L AB - The operating model (OM) for the South African anchovy resource has been updated from that used to develop OMP-14 given four more years of data. The model has been altered from previous assessments to now fit directly to length frequency data, removing the earlier need for estimates of proportions of anchovy-at-age 1 during the annual November hydroacoustic survey. A Beverton Holt stock recruitment relationship is used for the base case. Time-invariant natural mortality is assumed to be 1.2year^(-1) for both juvenile and adult natural mortality as before; this provides a better fit to the data than other options considered. The resource abundance is estimated to be near the historical (1984-2014) average, with a total biomass of 3.3 million tons in November 2015. Recruitment reflects three major peaks over the past 20 years, although the lowest points in these fluctuations were still large, being similar to the maximum recruitment prior to 2000. DA - 2016-10 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - Assessment of the South African anchovy resource using data from 1984 - 2015: results at the posterior mode TI - Assessment of the South African anchovy resource using data from 1984 - 2015: results at the posterior mode UR - http://hdl.handle.net/11427/23975 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/23975
dc.identifier.vancouvercitationde Moor CL. Assessment of the South African anchovy resource using data from 1984 - 2015: results at the posterior mode. 2016 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/23975en_ZA
dc.languageengen_ZA
dc.publisher.departmentMarine Resource Assessment and Management Groupen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.titleAssessment of the South African anchovy resource using data from 1984 - 2015: results at the posterior modeen_ZA
dc.typeWorking Paperen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceWorking paperen_ZA
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