东海北部哈氏仿对虾资源量评估

根据2005～2008年东海北部哈氏仿对虾的生物学数据,应用FISATⅡ软件的ElEFANⅠ技术计算生长参数,得到VonBertalanffy生长方程的相关参数为L∞=123.4mm,K=1.70,t0=-0.16,自然死亡系数M=2.55,总死亡系数Z=5.81,捕捞死亡系数F=3.26。应用长度结构的实际种群分析,得出稳定状态下资源量为2.86×104吨。利用Beverton-Holt和Thompson-Bell模型对单位补充量的产量Y/R和单位补充量的产值Yv/R进行分析,表明在现行状态下,该群体未出现过度捕捞现象。综合考虑当前可能的捕捞强度及经济效益,在有利于保持较高产量的前提下,建议在适当降低捕捞强度的同时把哈氏仿对虾的开捕体长由55.6mm增加至74.0mm。

Stock assessment of Parapenaeopsis hardwickii in the Northern East China Sea

Based on the monthly length - frequency data of Parapenaeopsis hardwickii obtained during 2005 - 2008 in the Northern East China Sea, the growth parameters was analysed by applying the ElEFANI. The result showed that the growth parameters of Von Bertalanffy growth equation was L∞ = 123. 4mm, K = 1.70, t0 = - 0. 16, natural mortality coefficient （M） was 2. 55, total mortality coefficient （Z） was 5.81. The Fishing Mortality Coefficient （F） in 2000s was calculated that F = 3.26. The Steady - state Biomass was 2. 86 × 104 t by using Length - Structured Virtual Population Analysis. Yield - per - recruit analysis and the value of yield - per - recruit analysis applying Beverton - Holt and Thompson - Bell model indicated that the stock resource of Parapenaeopsis hardwiddi can＇ t be exploited until the body length at first capture body length （Lc） reaches to 55. 6mm and F to 3.26. Taking into account the possible fishing effort and economic requirement, it＇ s suggested that Lc should be increased from 55. 6 mm to 74. 0 mm and great efforts in reducing fishing intensity should be made by the government.