Some refinements of the assessment of the South African squid resource, loligo vulgaris reynaudii
| dc.contributor.author | Glazer, Jean Patricia | |
| dc.contributor.author | Butterworth, Doug S | |
| dc.date.accessioned | 2016-03-11T11:23:58Z | |
| dc.date.available | 2016-03-11T11:23:58Z | |
| dc.date.issued | 2006 | |
| dc.date.updated | 2016-03-09T11:52:47Z | |
| dc.description.abstract | A biomass dynamic model making use of an observation error estimator has been used over recent years to assess the status of the squid resource, Loligo vulgaris reynaudii, off the coast of South Africa. This assessment has indicated the resource to be at a low level and the risk of collapse under the current level of fishing effort to be high. Accordingly, past scientific management advice has been that effort should be reduced. This assessment is refined here to take account of both observation and process error, and a number of sensitivity tests related to assumptions made in the original model are conducted. Bayesian analyses to take full account of estimation uncertainty are also undertaken. The results from the respective analyses are reported, and it is shown that changing the “hockey-stick” stock–recruitment function of the original model to a Beverton–Holt form opens the possibility that the resource is under less risk from the current level of effort than has been supposed. | en_ZA |
| dc.identifier | http://dx.doi.org/10.1016/j.fishres.2005.12.011 | |
| dc.identifier.apacitation | Glazer, J. P., & Butterworth, D. S. (2006). Some refinements of the assessment of the South African squid resource, loligo vulgaris reynaudii. <i>Fisheries Research</i>, http://hdl.handle.net/11427/17637 | en_ZA |
| dc.identifier.chicagocitation | Glazer, Jean Patricia, and Doug S Butterworth "Some refinements of the assessment of the South African squid resource, loligo vulgaris reynaudii." <i>Fisheries Research</i> (2006) http://hdl.handle.net/11427/17637 | en_ZA |
| dc.identifier.citation | Glazer, J. P., & Butterworth, D. S. (2006). Some refinements of the assessment of the South African squid resource, Loligo vulgaris reynaudii. Fisheries Research, 78(1), 14-25. | en_ZA |
| dc.identifier.issn | 0165-7836 | en_ZA |
| dc.identifier.ris | TY - Journal Article AU - Glazer, Jean Patricia AU - Butterworth, Doug S AB - A biomass dynamic model making use of an observation error estimator has been used over recent years to assess the status of the squid resource, Loligo vulgaris reynaudii, off the coast of South Africa. This assessment has indicated the resource to be at a low level and the risk of collapse under the current level of fishing effort to be high. Accordingly, past scientific management advice has been that effort should be reduced. This assessment is refined here to take account of both observation and process error, and a number of sensitivity tests related to assumptions made in the original model are conducted. Bayesian analyses to take full account of estimation uncertainty are also undertaken. The results from the respective analyses are reported, and it is shown that changing the “hockey-stick” stock–recruitment function of the original model to a Beverton–Holt form opens the possibility that the resource is under less risk from the current level of effort than has been supposed. DA - 2006 DB - OpenUCT DP - University of Cape Town J1 - Fisheries Research LK - https://open.uct.ac.za PB - University of Cape Town PY - 2006 SM - 0165-7836 T1 - Some refinements of the assessment of the South African squid resource, loligo vulgaris reynaudii TI - Some refinements of the assessment of the South African squid resource, loligo vulgaris reynaudii UR - http://hdl.handle.net/11427/17637 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/17637 | |
| dc.identifier.uri | http://www.sciencedirect.com/science/article/pii/S0165783605003322 | |
| dc.identifier.vancouvercitation | Glazer JP, Butterworth DS. Some refinements of the assessment of the South African squid resource, loligo vulgaris reynaudii. Fisheries Research. 2006; http://hdl.handle.net/11427/17637. | en_ZA |
| dc.language | eng | en_ZA |
| dc.publisher | Elsevier | 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.rights | Creative Commons Attribution Non-Commercial No Derivatives | |
| dc.source | Fisheries Research | en_ZA |
| dc.source.uri | http://www.sciencedirect.com/science/journal/01657836/78/1 | |
| dc.title | Some refinements of the assessment of the South African squid resource, loligo vulgaris reynaudii | en_ZA |
| dc.type | Journal Article | en_ZA |
| uct.subject.keywords | Loligo vulgaris reynaudii; Assessment; Biomass-based models; Observation error; Process error; Bayesian estimation; Projections | en_ZA |
| uct.type.filetype | Text | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Article | en_ZA |