Empirical weighting of multiple stock-abundance indices for parameter estimation and stock assessment in a multi-zone or multi-species fishery

Abstract

In order to make use of all available information, fishery stock assessment researchers often use several indices of stock abundance. These indices are derived from commercial, as well as fishery-independent sources. Since the indices all relate to the same fishery but may differ in the degree of accuracy with which they reflect stock size, appropriate weights must be chosen for each. This paper contains an outline of an empirical approach to assigning index weights via the likelihood function that underpins both classical and Bayesian statistical methods. The approach is demonstrated for a stimulated three-zone paua ( Haliotis iris ) fishery, and can be used readily for multi-species fisheries and/or for assessment of multiple-use management of marine resources.