A Bayesian assessment of the South Atlantic population of albacore which explicitly models changes in targeting

 

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dc.contributor.author Rademeyer, Rebecca A
dc.contributor.author Butterworth, Doug S
dc.contributor.author Penney, Andrew J
dc.date.accessioned 2016-03-14T09:09:27Z
dc.date.available 2016-03-14T09:09:27Z
dc.date.issued 2004
dc.identifier.citation Rademeyer, R. A., Butterworth, D. S., & Penney, A. J. (2004). A Bayesian Assessment of the South Atlantic population of albacore which explicitly models changes in targeting. Collect. Vol. Sci. Pap. ICCAT, 56(4), 1360-1390. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/17753
dc.description.abstract The primary assessment method applied to South Atlantic albacore during the October 2000 ICCAT SCRS assessment session was an age-structured production model which assumed a fleet-aggregated selectivity pattern with a single change only (in 1969), and estimated model parameters using only CPUE data. A particular problem of this approach is that the Japan CPUE series is not considered comparable over the complete period for which it is available because of changed targeting practices, so that this series needs to be split into three separate segments when estimating model parameters. This paper refines that 2000 assessment by treating the Japanese, Taiwanese and Brazilian fisheries all as initially primarily albacore directed fisheries which have shifted over time to bigeye tuna targeted fisheries, taking albacore as a decreasing bycatch. The transitions over time are explicitly estimated, as are separate selectivities for the two components of each national fishery by also including catch-at-age information in the data fitted by the model. Compared to the high levels of uncertainty in past assessments, the refined model provides a reasonable to good fit to all available information, and suggests that the productivity of the resource is somewhat higher than estimated previously. en_ZA
dc.language eng en_ZA
dc.publisher International Commission for the Conservation of Atlantic Tuna (ICCAT) Secretariat en_ZA
dc.relation.ispartofseries Collective Volume of Scientific Papers en_ZA
dc.source Collective Volume of Scientific Papers en_ZA
dc.subject.other Albacore
dc.subject.other South Atlantic
dc.subject.other stock assessment
dc.subject.other ASPM
dc.subject.other MCMC
dc.title A Bayesian assessment of the South Atlantic population of albacore which explicitly models changes in targeting en_ZA
dc.type Journal Article en_ZA
dc.date.updated 2016-03-14T08:40:07Z
uct.type.publication Research en_ZA
uct.type.resource Article en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Marine Resource Assessment and Management Group en_ZA
dc.identifier.apacitation Rademeyer, R. A., Butterworth, D. S., & Penney, A. J. (2004). A Bayesian assessment of the South Atlantic population of albacore which explicitly models changes in targeting. <i>Collective Volume of Scientific Papers</i>, http://hdl.handle.net/11427/17753 en_ZA
dc.identifier.chicagocitation Rademeyer, Rebecca A, Doug S Butterworth, and Andrew J Penney "A Bayesian assessment of the South Atlantic population of albacore which explicitly models changes in targeting." <i>Collective Volume of Scientific Papers</i> (2004) http://hdl.handle.net/11427/17753 en_ZA
dc.identifier.vancouvercitation Rademeyer RA, Butterworth DS, Penney AJ. A Bayesian assessment of the South Atlantic population of albacore which explicitly models changes in targeting. Collective Volume of Scientific Papers. 2004; http://hdl.handle.net/11427/17753. en_ZA
dc.identifier.ris TY - Journal Article AU - Rademeyer, Rebecca A AU - Butterworth, Doug S AU - Penney, Andrew J AB - The primary assessment method applied to South Atlantic albacore during the October 2000 ICCAT SCRS assessment session was an age-structured production model which assumed a fleet-aggregated selectivity pattern with a single change only (in 1969), and estimated model parameters using only CPUE data. A particular problem of this approach is that the Japan CPUE series is not considered comparable over the complete period for which it is available because of changed targeting practices, so that this series needs to be split into three separate segments when estimating model parameters. This paper refines that 2000 assessment by treating the Japanese, Taiwanese and Brazilian fisheries all as initially primarily albacore directed fisheries which have shifted over time to bigeye tuna targeted fisheries, taking albacore as a decreasing bycatch. The transitions over time are explicitly estimated, as are separate selectivities for the two components of each national fishery by also including catch-at-age information in the data fitted by the model. Compared to the high levels of uncertainty in past assessments, the refined model provides a reasonable to good fit to all available information, and suggests that the productivity of the resource is somewhat higher than estimated previously. DA - 2004 DB - OpenUCT DP - University of Cape Town J1 - Collective Volume of Scientific Papers LK - https://open.uct.ac.za PB - University of Cape Town PY - 2004 T1 - A Bayesian assessment of the South Atlantic population of albacore which explicitly models changes in targeting TI - A Bayesian assessment of the South Atlantic population of albacore which explicitly models changes in targeting UR - http://hdl.handle.net/11427/17753 ER - en_ZA


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