Use of a Multiplicative Model to Estimate Catch Rate and Effort from Commercial Data

Abstract

The multiplicative model described by Robson can be used to obtain estimates of annual standardized catch rate and its variance by including years in the model. The corresponding estimate of standardized effort is the ratio of the total catch and the estimated catch rate. If the error is assumed to be lognormally distributed then these estimators have well defined statistical properties.Key words: effort standardization, catch rate, multiplicative model, stock assessment