Alternative structural models for the Northeast Chatham Rise orange roughy fishery
| dc.contributor.author | Butterworth, Doug S | |
| dc.contributor.author | Brandão, Anabela | |
| dc.date.accessioned | 2016-04-20T07:28:53Z | |
| dc.date.available | 2016-04-20T07:28:53Z | |
| dc.date.issued | 2006 | |
| dc.date.updated | 2016-04-20T07:27:06Z | |
| dc.description.abstract | A particular difficulty with assessments of the Orange Roughy resource on the Northeast Chatham Rise is the seeming inability of standard population models, with their standard assumptions of a linear relationship between CPUE and survey indices to abundance, to simultaneously reflect the trends of all these indices. Especially concerning is that while the outputs from these models suggest a recovery in abundance for the Spawning Box after about 1992, the CPUE and hydroacoustic survey results for that period indicate the reverse. A number of mechanisms have been suggested that might be able to resolve these inconsistencies: resident-and-transient fish (related perhaps to spawning migrations), seasonal patterns, hyperdepletion, disturbance, intermittent aggregation, effort saturation and fishing behaviour (Anon. 2005). The purpose of this paper (following a proposal in Anon. 2005) is to investigate this using a simple age-aggregated population model as a basis. | en_ZA |
| dc.identifier.apacitation | Butterworth, D. S., & Brandão, A. (2006). <i>Alternative structural models for the Northeast Chatham Rise orange roughy fishery</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group. Retrieved from http://hdl.handle.net/11427/18992 | en_ZA |
| dc.identifier.chicagocitation | Butterworth, Doug S, and Anabela Brandão <i>Alternative structural models for the Northeast Chatham Rise orange roughy fishery.</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group, 2006. http://hdl.handle.net/11427/18992 | en_ZA |
| dc.identifier.citation | Butterworth, D. S., & Brandão, A. (2006). Alternative structural models for the Northeast Chatham Rise orange roughy fishery. MARAM: Universitry of Cape Town. | en_ZA |
| dc.identifier.ris | TY - Working Paper AU - Butterworth, Doug S AU - Brandão, Anabela AB - A particular difficulty with assessments of the Orange Roughy resource on the Northeast Chatham Rise is the seeming inability of standard population models, with their standard assumptions of a linear relationship between CPUE and survey indices to abundance, to simultaneously reflect the trends of all these indices. Especially concerning is that while the outputs from these models suggest a recovery in abundance for the Spawning Box after about 1992, the CPUE and hydroacoustic survey results for that period indicate the reverse. A number of mechanisms have been suggested that might be able to resolve these inconsistencies: resident-and-transient fish (related perhaps to spawning migrations), seasonal patterns, hyperdepletion, disturbance, intermittent aggregation, effort saturation and fishing behaviour (Anon. 2005). The purpose of this paper (following a proposal in Anon. 2005) is to investigate this using a simple age-aggregated population model as a basis. DA - 2006 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2006 T1 - Alternative structural models for the Northeast Chatham Rise orange roughy fishery TI - Alternative structural models for the Northeast Chatham Rise orange roughy fishery UR - http://hdl.handle.net/11427/18992 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/18992 | |
| dc.identifier.vancouvercitation | Butterworth DS, Brandão A. Alternative structural models for the Northeast Chatham Rise orange roughy fishery. 2006 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/18992 | en_ZA |
| dc.language | eng | en_ZA |
| dc.publisher.department | Marine Resource Assessment and Management Group | en_ZA |
| dc.publisher.faculty | Faculty of Science | en_ZA |
| dc.publisher.institution | University of Cape Town | |
| dc.title | Alternative structural models for the Northeast Chatham Rise orange roughy fishery | en_ZA |
| dc.type | Working Paper | en_ZA |
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Research paper | en_ZA |