Study of stock and management of Nemipterus virgatus in southwestern continental shelf of Nansha Islands

The stock status of Nemipterus virgatus (Houttuyn), is analyzed according to twice survey data in southwestern continental shelf of Nansha Islands of spring and autumn in 2003 and referring to the similar survey data from 1990 to 1993. The results show the catch rate varies with season, and is more in autumn (1.13 kgh-1) than in spring (1.07 kgh-1), the same as the average body-length and body-weight,the range of predominant body-length is during 151~190 mm in spring and 141~220 mm in autumn,and it mainly distributes in depth of 91~100 m. The stock of this species has decayed markedly, with the average catch rate decreasing from 3.32 kgh-1 to 1.10 kgh-1, the stock density from 36.73 kgkm-2 to 14.37 kgkm-2and the biomass from 3 178.60 t to 1 053.15 t. The present abundance is only 33.24% of the original. The management measures and advices of this species stock are also put forward in the paper.