A gender-disaggregated assessment of the South African hake resource, fitting directly to age-length keys: a new reference case

Rademeyer, Rebecca A; Butterworth, Doug S

A gender-disaggregated assessment of the South African hake resource, fitting directly to age-length keys: a new reference case

Working Paper

2009

Publisher

University of Cape Town

Department

Marine Resource Assessment and Management Group

Faculty

Faculty of Science

Abstract

The assessment methodology for the hake resource is refined to take account of recommendations made by the Panel at the December 2008 International Stock Assessment Workshop to move to a gender-disaggregated model, and to fit directly to age data and estimate growth curve parameters directly in the likelihood maximisation process. This approach proves to remove the conflict between fits to catch-at-age and catch-at-length distributions evident in earlier assessments. The current M. paradoxus female spawning biomass is estimated to be at 76% of its MSY level, while the corresponding M. capensis estimate well above this level.