Compositional analysis of catch curve data, with an application to Sebastes maliger

Schnute, J. T. and Haigh, R. 2007. Compositional analysis of catch curve data, with an application to Sebastes maliger. – ICES Journal of Marine Science, 64: 218–233. This paper applies modern compositional analysis to catch curve data from a quillback rockfish (Sebastes maliger) population in British Columbia, Canada. Bubble plots and ternary diagrams portray variable age distributions and highlight distinctions between commercial and survey sample data. The models formalize important historical issues in catch curve analysis related to selectivity and recruitment variability, where a particular model corresponds to a prescribed vector of design parameters. The roles that compositional distributions (multinomial, Dirichlet, logistic-normal) can play in fishery data analysis are described, and Bayesian methods are used to examine how the distribution of a key mortality parameter depends on model choice. The framework provides a direct link between model designs and policy outcomes that depend on estimated mortalities or mortality ratios.