Estimation and mapping of fishing effort, size-class of catches and CPUEs for the fishery of the deep-sea red shrimp Aristeus antennatus in Catalonia (NE Spain) using Vessels Monitoring System data and daily landings per size class

Abstract

The deep-sea red shrimp Aristeus antennatus is the most valuable demersal resource exploited by the trawling fleets of Catalonia (NE Spain). In this area, the abundance of this species displays important seasonal fluctuations, forming dense aggregations at different depths in different times of the year. The fishing fleet is known to target such aggregations. In this context, detailed knowledge of spatial and temporal distribution of the fishing effort and size-class of catches is crucial, if we are to establish an ad hoc management strategy involving specific actions on a seasonal or spatial basis, such as temporary and spatial fishing closures. For this study we obtained from the Spanish Ministry of Agriculture, Livestock and Fishery the VMS (Vessels Monitoring System) data relative to the trawling fleets of Catalonia from 2005 to the actuality. For two of the main ports in the area, Blanes and Palamós, we also disposed of data on daily landings per vessel per each commercial size of the resource (four for Palamós and two for Blanes), supplied by the local fishermen associations. By merging the two datasets, we were finally able to draw maps showing spatial distribution of fishing effort, catches and CPUEs at different times of the year, considering size classes altogether or separately. The results obtained so far show that fishing effort concentrates on the heads of the submarine canyons. These areas host a consistent aggregation of juveniles of red shrimp typically in winter, when they are recruiting to the fishing area from deeper waters