Understanding the spatio-temporal variability of fisheries data for better bottom trawling management practices in the Catalan margin (NW Mediterranean Sea)

The long-time fishery tradition on the Mediterranean coastal region without a biological-base management strategy has led to an overexploitation of the main fishing resources. To overturn this trend, the European Union implemented the Western Mediterranean Multi-Annual Plan (WMMAP) aiming to better manage key commercial species caught by bottom trawling. The data to drive management decisions should be obtained from fisheries monitoring programs designed to collect data that reflect dynamics of both biological and spatio-temporal trends in different spatial extents and scales. With this in mind, the aim of this research is to analyze the spatio-temporal variability of the commercial fraction of the catch, focusing on the main fishing resources of the Catalan bottom trawling fleet throughout the GSA 6. The Institut Català de Recerca per a la Governança del Mar (ICATMAR) designed a locally-based monitoring program to collect biological data for seven main key fishing resources of the area including the spottail mantis shrimp, the red mullet, the horned octopus, the European hake, the deep-water rose shrimp, the Norway lobster and the blue and red shrimp. The study shows the patterns that affect the main fishing resources exploited by the Catalan bottom trawling fleet over space and time through the study of biological data relevant to fisheries. To develop best management practices, we suggest that this type of sampling be included in Mediterranean areas to complement the current Data Collection Framework (DCF) program, so that fisheries can be managed evaluating the biology of the species along with the social component of the fisheries structure.