Solea solea: landings data and LPUE standardization from official logbooks in Atlantic Iberian waters

Abstract

Time series of abundance indices are the main source of information to calibrate stock assessment models. Standardized LPUEs (Landings per unit effort) derived from fishery-dependent data can be used as a proxy of the species abundance. In this study we present a first attempt of standardization of landings per unit of effort (LPUE) for soleid species. Soleid species, in particular the common sole (Solea solea), are important fisheries resources with high economic value, targeted by the Spanish fleet in Iberian Atlantic waters. Nevertheless, information on these resources is scarce. Time series data from 2009 to 2020 from the official logbooks of the Spanish fleet operating in the ICES subdivisions 8.c and 9.a. have been analysed in order to provide some insights into this fishery. Uncertainties in the accuracy of the identification of the species led to the aggregation of 6 taxa: Solea solea, Solea senegalensis, Solea elongata, Solea spp., Pegusa lascaris and Pegusa cadenati, as one single category, being the common sole, Solea solea, the most important taxon in terms of economic value and landings. Landings per unit of effort (LPUE) based on the estimated soleid species landed weight by fishing days (unit effort), for the most important métiers in terms of landings, were used as response variable. Generalised linear mixed models, fitted with a Gamma distribution, were employed, and several explanatory variables were tested to be included in the models: year, quarter, month, ICES division, statistical rectangle, landing port, vessel characteristics (LOA category, vessel power), depth, fishing time and number of fishing operations.