A proposed management procedure for the toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands vicinity

• Main Authors: Brandão, Anabela, Butterworth, Doug S
• Format: Report
• Language: English
• Published: University of Cape Town 2008
• Subjects: Tac; Prince Edward Islands
• Online Access: http://hdl.handle.net/11427/18538; https://open.uct.ac.za/bitstream/11427/18538/1/Brand%c3%a3o_A_proposed_management_2008.pdf

Four Operating Models (OMs) reflecting an “Optimistic”, “Intermediate”, “Less Pessimistic” and a “Pessimistic” current status for the toothfish resource in the Prince Edward Islands region are developed which take account of the different selectivities of past longline and pot fisheries. These models are used for trials of a candidate Management Procedure (MP) which could provide future TAC recommendations for this resource. The MP uses two data sources: the recent trend in longline CPUE and the mean length of the catches made. A specific MP, with its associated control parameter values, is proposed for implementation based upon the results of the trials. Given the importance of an adequate catch rate for the economic viability of the fishery, the choice of control parameter values focused primarily on a reasonable probability of securing a catch rate increase, whatever the current resource status. MP performance is reasonably robust across a range of sensitivity tests, though does deteriorate in conservation terms if steepness h is low. These tests also indicate that monitoring of future catch-at-length information would be necessary to guard against a change in selectivity towards greater catches of older fish.