摘要： 为了探索南海金枪鱼延绳钓合适作业参数，根据2010年6月至2013年2月8个航次的南海金枪鱼延绳钓探捕调查数据，估算了大眼金枪鱼和黄鳍金枪鱼在不同水层的渔获率，以浮子绳长度hf、两浮子间钩数n和短缩率k这三个作业参数的调整为研究对象，采用最小二乘法来度量不同水层上钓钩分布频率与金枪鱼渔获分布频率的匹配程度。当两者之间的频差平方和达到最小值时，即认为找到延绳钓最适作业结构。结果显示：hf=34 、n=25、k=0.68对捕捞大眼金枪鱼最合适；hf=10、n=14、k=0.71对捕捞黄鳍金枪鱼最合适；两种兼顾时，hf=8、n=27、k=0.69更合适。

关键词: 金枪鱼, 延绳钓, 作业参数, 南海

Abstract: In order to understand the suitable operation parameters of tuna longline in South China Sea, catch rate in different water layers were estimated for Thunnus obesus and Thunnus albacre based on 8 voyages of tuna longline survey data from June 2010 to February 2013 in South China Sea. With adjustment of three operation parameters - float line length hf, numbers of hook between two floats n and sag ratio k as the object of study, matching degree of hook distribution frequency with tuna harvesting distribution frequency in different water layers was measured by least square method. The most suitable operation structure of logline was found as the sum of squared frequency difference was minimized. The result showed that hf=34, n=25, k=0.68 were the most suitable for targeting Thunnus obesus; hf=10, n=14, k=0.71 were the most suitable for targeting Thunnus albacre; hf=8, n=27, k=0.69 were more suitable for targeting both species.

Key words:  tuna, longline, operation parameters, South China Sea