Avaluació i anàlisi de la pressió pesquera a la costa de Catalunya mitjançant dades VMS

Abstract

Fishing pressure is understood as the level of activity of fishing fleets, and when this is very high it can generate what is known as overfishing and consequently all the negative effects on biodiversity that can be derived. In this study, we intend to make a global analysis of this problem in the Catalan coast during the last ten years by three different fishing methodologies: trawling seine fishing and surface longline, and thus be able to observe what trends are present in the fleets fishing activities relating to compliance with legislation. It is also intended to observe how the three fishing methods studied have evolved, either in the number of vessels or in the intensity of the fishing activity. To carry out the aforementioned tasks, a cartography has been drawn up in which the spatial distributions during the series from 2009 to 2018 can be appreciated, for each art and year, and thus be able to observe in detail the differences existing in the spatial distributions of each year after year. In these maps it is observed that for the three arts, there are several infractions referring to the regulations, and as a special case, the delta of the Ebro by the art of drag, since it is the clearest case of all. Next, a part of this study has also been dedicated to an analysis by seasons, that is, what are the possible effects of the different seasons of the year on the spatial distributions of the fishing fleets. In order to fulfil this last analysis, the data of the whole year 2018 have been separated according to the season of the year in which they were, that is, winter, spring, autumn and summer, and a map has been drawn up for each art and station of the year, obtaining a total of twelve. In this last analysis, the possibility of observing the effects of the implementation of temporary closures on the spatial distributions of the fishing fleets has been interesting, since it has been seen that while in the areas delimited by the closure the fishing activity is practically null , in the rest of the Catalan coastal areas, the fishing intensity increases. As main conclusions, this study allows us to say that VMS data are a good tool to control fishing, and in the specific case of the coast of Catalonia it is clear that this control is not being done correctly since there are too infractions