Exploratory analyses of the Agulhas sole assessment

A number of different production model approaches are considered for assessment of the Agulhas sole resource, Stationary models, either with observation error only estimation, or adding annual process error, exhibit systematic patterns in residuals. The best approach seems to be to postulate a non-stationary situation, with some change in the dynamics of the resource (or equivalently in the fishery catchability q) in the new century. Some initial comments are made as regards the next steps needed to advance this approach further