Abstract
This document presents a standardized index update of adult yellowfin (>30 kg) of tropical purse seine fleets in the Atlantic Ocean from 1980 to 2006. The data used were taken from spear fishing logbooks and detailed information of the fleet. The standardization has been carried out by generalized linear models (GLM) using the delta model. The standardized indices are obtained from the GLM model estimations: one is calculated from the least squares means (LSMeans) and another from the annual averages of the adjusted values. The variability of the latter is lower. Therefore, in this case, it is a more adequate index to be used in assessment models. The year, country, category, age of vessel and catches of skipjack tuna, which is the other target species of these fleets, were considered as explanatory variables.