FISHERIES_2020_OCT_SWG-DEM_24Rev.pdf (399.27 kB)

Key aspects of the proposed Management Procedure for the Toothfish (Dissostichus eleginoides) Resource in the Prince Edward Islands vicinity

Download (399.27 kB)
report
posted on 29.01.2021, 10:23 by Anabela Brandao, Doug Butterworth
This paper summarises the key aspects and results of analyses conducted to develop a Management Procedure (MP) for toothfish. This is to assist focus the discussion required in the Demersal Working Group to formulate and agree upon a recommendation for its adoption. All background details can be found in Brandão and Butterworth (2020). This MP inputs information on trends in the cumulative number of recaptured tags as well as the recent mean of the trotline CPUE, considers an initial smoothing of the TAC, is tuned to a target of 40% for the median final depletion under toothfish Operating Model OM10 and constrains the TAC to a maximum inter-annual change of 10%. This MP performs satisfactorily under most of the OMs, in that median catches increase for most of the projection period while catch rates continue to increase and the median final depletion remains above the specified target value under OM10. The application of an initial TAC smoothing mechanism largely eliminates an earlier problematic pattern of an initial increase before a later drop in TACs fairly soon thereafter.

History

Department/Unit

Department of Mathematics and Applied Mathematics, University of Cape Town