Trends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously.

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dc.contributor.authorBrandão, Anabela
dc.contributor.authorButterworth, Doug S
dc.date.accessioned2020-01-28T08:57:00Z
dc.date.available2020-01-28T08:57:00Z
dc.date.issued2019
dc.description.abstractResults are given for an approach which simultaneously models the “old” and the “new” databases as recommended by the Panel for the 2018 International Fisheries Stock Assessment Workshop. These results are compared to two previous GLM methods reported by Brandão and Butterworth (2018a); a) a GLM applied to the “new” compliance database, and b) a GLM method applied to the “old” database in which estimates of relative effort efficiencies obtained from the “new” database are used to link effort to the number of confiscations (“old”-linked). By simultaneously modelling the “old” and the “new” databases, information on the trend in poaching, as well as on the relative efficiencies of different effort types from the “new” database, influence the estimates of poaching trends obtained from the combined model. However, due to the fact that the “old” database is a summation of operations which produced a number of instances of confiscations (including cases of zero confiscations), while the “new” database reports individual incidents with non-zero confiscations, undue weight is being given to the information available in the “new” database if data from each are equally weighted. We therefore advocate that an analysis which upweights the data in the “old” database should be used in the model which combines use of both the ”old” and “new” database values, and that this should serve as the primary basis for inferring poaching trends.en_US
dc.identifier.apacitationBrandão, A., & Butterworth, D. (2019). <i>Trends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously</i> ,Faculty of Science ,Department of Mathematics and Applied Mathematics. Retrieved from http://hdl.handle.net/11427/30817en_ZA
dc.identifier.chicagocitationBrandão, Anabela, and Doug Butterworth <i>Trends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously.</i> ,Faculty of Science ,Department of Mathematics and Applied Mathematics, 2019. http://hdl.handle.net/11427/30817en_ZA
dc.identifier.citationBrandão, A., Butterworth, D. 2019. Trends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously.en_ZA
dc.identifier.ris TY - Report AU - Brandão, Anabela AU - Butterworth, Doug AB - Results are given for an approach which simultaneously models the “old” and the “new” databases as recommended by the Panel for the 2018 International Fisheries Stock Assessment Workshop. These results are compared to two previous GLM methods reported by Brandão and Butterworth (2018a); a) a GLM applied to the “new” compliance database, and b) a GLM method applied to the “old” database in which estimates of relative effort efficiencies obtained from the “new” database are used to link effort to the number of confiscations (“old”-linked). By simultaneously modelling the “old” and the “new” databases, information on the trend in poaching, as well as on the relative efficiencies of different effort types from the “new” database, influence the estimates of poaching trends obtained from the combined model. However, due to the fact that the “old” database is a summation of operations which produced a number of instances of confiscations (including cases of zero confiscations), while the “new” database reports individual incidents with non-zero confiscations, undue weight is being given to the information available in the “new” database if data from each are equally weighted. We therefore advocate that an analysis which upweights the data in the “old” database should be used in the model which combines use of both the ”old” and “new” database values, and that this should serve as the primary basis for inferring poaching trends. DA - 2019 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PY - 2019 T1 - Trends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously TI - Trends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously UR - http://hdl.handle.net/11427/30817 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/30817
dc.identifier.vancouvercitationBrandão A, Butterworth D. Trends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously. 2019 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/30817en_ZA
dc.language.isoeng
dc.publisher.departmentDepartment of Mathematics and Applied Mathematicsen_US
dc.publisher.facultyFaculty of Scienceen_US
dc.titleTrends in poaching for West Coast rock lobster from modelling the “old” and the “new” databases simultaneously.en_US
dc.typeReporten_US
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