The red shrimp Aristeus antennatus (Risso, 1816) fishery and biology in the Balearic Islands, Western Mediterranean

The present study updates the information on the red shrimp fishery in the waters of the Balearic Islands in the middle of the Western Mediterranean, from its beginning to the present. Also, the development of the fishery and the biology of the shrimp population exploited from 1992 to 1997 is analysed. The red shrimp (Aristeus antennatus) is one of the most important resources of bottom trawling in the Balearic Islands. It is fished on the slope between depths of 400 to 800 m. In biomass, it represents an average of 5% of the overall catches, but its economic value is 30% of the total earnings of the fishery. From 1948 to 1997, the landing increased at an average rate of 3405 kg per year. However, this increment was not constant for the whole period, and has been decreasing in the last five years. The engine power of boats fishing on the slope of the Balearic Islands doubled from the 1970s until the end of the study. At the moment, the number of fishing units is decreasing, although the power of the individual boats is increasing continuously. The trawl yields varied between 3 and 14 kg/h. The highest yields occurred in winter and spring. The decline of the sizes at first capture in 1997 and the increase of juveniles. in the catches can be interpreted as a change in the fishery strategy, which has increased the exploitation effort on the small sizes. (C) 1999 Elsevier Science B.V. All rights reserved.