Updated specifications, conditioning results and projections for the Hake OMP2018 Reference Set models

Abstract

The 2018 Reference Set of Operating Models used for testing OMP2018 was not fully endorsed by the Panel for the 2018 International Stock Assessment workshop. This document provides results for an updated RS that take account of the recommendations made by the Panel to address the reasons why they did not fully endorse these OMs, and projects them forward under the rules of OMP2018. There are some substantial changes to certain of the Beverton-Holt models (primarily as a result of finding improved minima for model fits rather than of correcting other of the issues identified by the Panel). These reflect more instances of an M. capensis population currently below its MSY level, but this status is not well determined in terms of the likelihood; furthermore, arguably these results are less plausible than those for the Ricker model, the fits for which have an appreciably better likelihood and reflect this population to be above its MSY level at present. This uncertainty about the status of the M. capensis population notwithstanding, projections for the updated Reference Set under OMP2018 indicate that the performance of this OMP remains fully adequate.