{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/10261"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/10261","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Modelling dominance shifts of anchovy and sardine with a frame-based approach : sensitivity to the underlying sardine population dynamics","abstract":"It has been shown that sardine and anchovy populations in the southern Benguela have alternated dominance during the past 50 years, and a frame based model that explores the usefulness of frames within a marine ecosystem by modelling sardine/anchovy dominance shifts in the southern Benguela has been developed in a previous study. The existing model contains a sardine population sub-model without age structure and the inclusion of age-structure allows age-related dynamics to be incorporated in the model design. In this mini-dissertation, an age-structured sardine population is implemented in the frame based model by using the sardine assessment model from the joint sardine/anchovy Operational Management Procedure, OMP-02. Methods for incorporating biological processes - such as the hypothesised school trap phenomena - that were present in the existing frame based model into the OMP-02 equations are developed, critically analysed and tested.","abstract_html":"It has been shown that sardine and anchovy populations in the southern Benguela have alternated dominance during the past 50 years, and a frame based model that explores the usefulness of frames within a marine ecosystem by modelling sardine/anchovy dominance shifts in the southern Benguela has been developed in a previous study. The existing model contains a sardine population sub-model without age structure and the inclusion of age-structure allows age-related dynamics to be incorporated in the model design. In this mini-dissertation, an age-structured sardine population is implemented in the frame based model by using the sardine assessment model from the joint sardine/anchovy Operational Management Procedure, OMP-02. Methods for incorporating biological processes - such as the hypothesised school trap phenomena - that were present in the existing frame based model into the OMP-02 equations are developed, critically analysed and tested.","abstract_has_math":false,"creators":["Botha, Jakobus Stephanus"],"institution":"Department of Oceanography","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Jarre, Astrid"],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012","date_published":"2012","updated_at":"2026-07-22T22:22:55Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/10261","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Jarre, Astrid"]},{"key":"dc:creator","label":"Author","values":["Botha, Jakobus Stephanus"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-12-27T14:17:04Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-12-27T14:17:04Z"]},{"key":"dc:date.issued","label":"Date","values":["2012"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Oceanography"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/10261"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Includes bibliographical references."]},{"key":"dc:description.abstract","label":"Abstract","values":["It has been shown that sardine and anchovy populations in the southern Benguela have alternated dominance during the past 50 years, and a frame based model that explores the usefulness of frames within a marine ecosystem by modelling sardine/anchovy dominance shifts in the southern Benguela has been developed in a previous study. The existing model contains a sardine population sub-model without age structure and the inclusion of age-structure allows age-related dynamics to be incorporated in the model design. In this mini-dissertation, an age-structured sardine population is implemented in the frame based model by using the sardine assessment model from the joint sardine/anchovy Operational Management Procedure, OMP-02. Methods for incorporating biological processes - such as the hypothesised school trap phenomena - that were present in the existing frame based model into the OMP-02 equations are developed, critically analysed and tested."]},{"key":"dc:title","label":"Title","values":["Modelling dominance shifts of anchovy and sardine with a frame-based approach : sensitivity to the underlying sardine population dynamics"]}]}],"canonical_facts":{"dc:contributor.advisor":["Jarre, Astrid"],"dc:creator":["Botha, Jakobus Stephanus"],"dc:date.accessioned":["2014-12-27T14:17:04Z"],"dc:date.available":["2014-12-27T14:17:04Z"],"dc:date.issued":["2012"],"dc:description":["Includes bibliographical references."],"dc:description.abstract":["It has been shown that sardine and anchovy populations in the southern Benguela have alternated dominance during the past 50 years, and a frame based model that explores the usefulness of frames within a marine ecosystem by modelling sardine/anchovy dominance shifts in the southern Benguela has been developed in a previous study. The existing model contains a sardine population sub-model without age structure and the inclusion of age-structure allows age-related dynamics to be incorporated in the model design. In this mini-dissertation, an age-structured sardine population is implemented in the frame based model by using the sardine assessment model from the joint sardine/anchovy Operational Management Procedure, OMP-02. Methods for incorporating biological processes - such as the hypothesised school trap phenomena - that were present in the existing frame based model into the OMP-02 equations are developed, critically analysed and tested."],"dc:identifier.uri":["http://hdl.handle.net/11427/10261"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Oceanography"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Modelling dominance shifts of anchovy and sardine with a frame-based approach : sensitivity to the underlying sardine population dynamics"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:22:55Z"}