This paper presents the results obtained from applying an objective classification method to the daily commercial landings
data of the Spanish bottom-trawl fishery off the Gulf of Cádiz for defining mixed-species fisheries or fishing trip types.
Definition of these operational fisheries was based on the relatively unique and homogeneous species composition of the
landings and technical characteristics of the vessels. The method was based on cluster (CA) and linear discriminant (DA)
analysis techniques. The application of CA techniques to the 1993 data matrix of daily catch per unit of effort per species
and active vessel resulted in the identification of 22 types of fishing trips, which were defined by the relative importance
of their target and accessory species. Subsequently, different linear discriminant functions were derived for each FTT in
order to classify new records. Five different fleet types were also identified through CA techniques according to the vessel’s