为了解印度洋大眼金枪鱼(Thunnus obesus)温跃层参数适宜分布区间及季节变化,采用Argo浮标剖面温度数据重构热带印度洋各月平均温跃层特征参数,并结合印度洋金枪鱼委员会(IOTC)大眼金枪鱼延绳钓渔业数据,本文绘制r月平均温跃层特征参数和月平均CPUE的空间叠加图,用于分析热带印度洋大眼金枪鱼渔场CPUE时空分布和温跃层特征参数的关系.结果表明,热带印度洋温跃层上界深度、温度和下界深度都具有明显的季节性变化,大眼金枪鱼中心渔场分布和温跃层季节性变化有关.夏季季风期间,高CPUE渔区温跃层上界深度在30～50 m,浅于冬季的50～70 m;温跃层上界温度范围为24～30℃.在冬季季风期间,高CPUE区域对应的温跃层上界温度范围为27～30℃;从马达加斯加岛北部沿非洲大陆至索马里附近海域,温跃层下界深度在170～200 m时的渔区CPUE普遍较高；当深度超过300 m时,CPUE值均非常低.采用频次分析和经验累积分布函数计算其最适温跃层特征参数分布,得出大眼金枪鱼最适温跃层的上界、下界温度范围分别是26～29℃和13～15℃；其上界、下界深度范围分别是30～60 m和140～170m.文章初步得出印度洋大眼金枪鱼中心渔场温跃层各特征参数的适宜分布区间及季节变化特征,为金枪鱼实际生产作业和资源管理提供理论参考.%This study plotted spatial overlay maps to analyze the relationship between bigeye tuna (Thunnus obesus) distribution in fishing grounds in the tropical Indian Ocean and thermocline characteristics, calculated from monthly temperature profile data from Argo buoys and the monthly CPUE (catch per unit effort) from bigeye tuna longlines. Seasonal variability was observed in the depth of the upper boundary temperature and in the lower boundary depth. Our analysis suggested that the distribution of bigeye tuna was related to these seasonal variations of the thermocline. The range of the upper boundary depth for high CPUE during the summer monsoon was 30-50 m, which was lower than in the winter (50-70 m). A higher CPUE was found from northern Madagascar to Somalia where the lower boundary depth was at 170-200 m. Where the lower boundary depth was more than 300 m, the value of CPUE was low. The range of upper boundary temperatures in the higher CPUE fishing grounds was 27-30 m during the winter monsoon and 24-30 m the summer monsoon. Frequency analysis and the empirical cumulative distribution function (ECDF) were used to compute the optimum range of thermocline characteristics. The optimum depth range of the upper boundary temperature was 26-29 m and the for the lower boundary temperature, it was 13-15 m. The optimum range of the upper boundary depth was 30-60 m and the lower boundary depth was 140-170 m. The conclusions were confirmed using Kolmogorov-Smirnov test. The suitable distribution interval and seasonal change characterize of each thermocline in the central fishing ground of bigeye tuna were preliminary obtained in this paper. The results could provide reference to longline production operation in sea and resource management.
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