Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks
| dc.contributor.author | Brandão, Anabela | |
| dc.contributor.author | Butterworth, Doug S | |
| dc.date.accessioned | 2016-03-29T13:39:11Z | |
| dc.date.available | 2016-03-29T13:39:11Z | |
| dc.date.issued | 2003 | |
| dc.date.updated | 2016-03-29T13:37:39Z | |
| dc.description.abstract | Updated assessments of the four orange roughy aggregations off Namibia, based upon a maximum penalised likelihood approach which uses all available indices of abundance, are presented, and projections under constant catch levels reported. Earlier methodology is extended to reflect the proportion of a stock present at the fishing aggregation each year governed by a beta distribution. This new methodology is argued to provide the most reliable assessment of the resource. It suggests that Johnies, Frankies and Rix are all presently at some 60% of their preexploitation level, but that Hotspot is perhaps much more depleted. Overall, medium term sustainable yields would seem to be in the 2 500 – 3 500 ton range. However, variable aggregation levels from year to year would lead to difficulties in making a catch of this size every year. | en_ZA |
| dc.identifier.apacitation | Brandão, A., & Butterworth, D. S. (2003). <i>Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group. Retrieved from http://hdl.handle.net/11427/18360 | en_ZA |
| dc.identifier.chicagocitation | Brandão, Anabela, and Doug S Butterworth <i>Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks.</i> University of Cape Town ,Faculty of Science ,Marine Resource Assessment and Management Group, 2003. http://hdl.handle.net/11427/18360 | en_ZA |
| dc.identifier.citation | Brandão, A., & Butterworth, D. S. (2003). Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks. Namibian Ministry of Fisheries and Marine Resources document DWFWG/WkShop/Mar03/Doc, 3. | en_ZA |
| dc.identifier.ris | TY - Working Paper AU - Brandão, Anabela AU - Butterworth, Doug S AB - Updated assessments of the four orange roughy aggregations off Namibia, based upon a maximum penalised likelihood approach which uses all available indices of abundance, are presented, and projections under constant catch levels reported. Earlier methodology is extended to reflect the proportion of a stock present at the fishing aggregation each year governed by a beta distribution. This new methodology is argued to provide the most reliable assessment of the resource. It suggests that Johnies, Frankies and Rix are all presently at some 60% of their preexploitation level, but that Hotspot is perhaps much more depleted. Overall, medium term sustainable yields would seem to be in the 2 500 – 3 500 ton range. However, variable aggregation levels from year to year would lead to difficulties in making a catch of this size every year. DA - 2003 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2003 T1 - Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks TI - Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks UR - http://hdl.handle.net/11427/18360 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/18360 | |
| dc.identifier.vancouvercitation | Brandão A, Butterworth DS. Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks. 2003 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/18360 | 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 | Stock assessment of Namibian orange roughy populations using an age-structured production model and all available indices of abundance from 1994 to 2002, and making allowance for annually variable aggregation of the stocks | en_ZA |
| dc.type | Working Paper | en_ZA |
| uct.type.filetype | ||
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Research paper | en_ZA |