Refined trends in poaching for West Coast rock lobster based upon information from the DAFF compliance “new” database for the period 2012 to 2017, and final poaching trends used for updated assessments and projections
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2018-11
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Abstract
GLM methods are applied to the DAFF “new” compliance database in which policing effort is linked to confiscations taken as well as to the “old” compliance database on confiscations (and abandonments) and on policing effort (but restricting the analyses to policing effort types that are common with the “new” database) to estimate recent trends in the amount of rock lobster that is poached. GLM methods are also applied to this “old” database, but estimates of relative effort efficiencies for different effort types obtained from the “new” database (and adjusted to account for inspections with zero confiscations which are not recorded in the “new” database) are used to link effort to the number of confiscations to provide a refined “old”-linked time series for the level of poaching. Because the number of data in the “new” database is so much less (only some 0.5%) than in the “old” database, it was decided that the “new” database analyses be used only to provide estimates of relative efficiency of different effort types, and that the “old”-linked series serve as the basis for the assumptions concerning poaching needed for future assessments. This document finally reports the basis underlying the selected Base Case and two sensitivities for poaching estimates and trends developed by the WCRL Task Group (TG) which was appointed for that purpose. The TG’s proposals were based on analyses of both DAFF Compliance data and import-export data compiled by TRAFFIC, which were used for updated assessments and projections of the resource.
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Reference:
Brandão, A., Butterworth, D., Johnston, S. 2018-11. Refined trends in poaching for West Coast rock lobster based upon information from the DAFF compliance “new” database for the period 2012 to 2017, and final poaching trends used for updated assessments and projections.