ASSESSMENT OF SHRIMP STOCK BIOMASS IN CONTINENTAL SHELF WATERS OF THE EAST CHINA SEA

On the basis of data from beam shrimp trawl net surveys in four seasons of 2008 and 2009 in the East China Sea Region, the existing shrimp stock in the surveyed areas and MSY were assessed by using stock density method for the first time. The result showed that the seasonal average stock density was 203.5 kg/km2. The density was the highest in summer and the lowest in winter, and it was the highest in southern area and the lowest in middle area. The current shrimp stock was approximately 10.6×104 t and MSY approximately was 22.2×104 t. The MSY was higher than the catches in 2008, which demonstrated that the shrimp resources were not fully exploited and were worthy to be further exploited. The current shrimp stock and MSY of Parapenaeus fissuroides was the highest among the main economic shrimps. The resources of the species that had more economic value such as Parapenaeopsis hardwickii and Penaeus japonicus decreased obviously, but resources of low economic species raised gradually, which indicated that the component of shrimp resources had been significantly changed in the continental shelf waters of the East China Sea.