Fishing Effort Increase and Resource Status of the Deep-Sea Red Shrimp Aristeus antennatus (Risso 1816) in the Northwest Mediterranean Sea Since the 1950s

The deep-sea red shrimp Aristeus antennatus is one of the most valuable demersal resources for bottom trawl fishery in the Mediterranean Sea. Nevertheless, this fishery lacks specific management at Mediterranean level, data availability is sparse and official records are often unreliable. In particular, misreporting of trawlers engine power is a widespread issue, complicating the process of fish stock assessments. In Catalonia (Northeast Spain), the red shrimp is particularly important and the stock has been traditionally exploited. The aim of this study was to investigate the long-term effects of intense fishing activities on this resource. For this purpose, we built a reliable series of fishing effort and catch per unit of effort (CPUE), integrating official data with information obtained by interviews to fishermen. Stock assessment at two different time periods, 1984-1989 and 20082010, was performed. In this study, we provide the first evidence of the remarkable increase of fishing effort in the Northwest Mediterranean Sea in the last decades. Overfishing of the red shrimp was detected at all years studied. A decrease in the yield per recruit and mean individual length over the two time periods considered was also detected. In addition, the CPUE presented a marked decreasing trend, indicating a possible reduction in the resource abundance. Our results show that an appropriate fishery management for this resource is needed, and should aim at reducing fishing mortality and increasing yield per recruit. These objectives could be achieved by reducing fishing effort and increasing size at first capture.