印度洋金枪鱼延绳钓主要渔获种类及分布

根据印度洋金枪鱼管理委员会IOTC的金枪鱼生产数据库,对1967-2004年间印度洋金枪鱼延绳钓主要渔获种类的产量按年进行汇总和基于5度格网进行了空间上的统计,采用GIS软件制作了印度洋金枪鱼延绳钓主要渔获种类的捕捞产量的地理空间分布图,分析了其资源的空间分布特征。分析结果表明,大眼金枪鱼Thunnus obesus、黄鳍金枪鱼Thunnus albacares、长鳍金枪鱼Thun-nus alalunga和剑鱼Xiphias gladius是印度洋金枪鱼延绳钓的主要渔获种类,其产量之和占到总产量的90%,这4种印度洋金枪鱼延绳钓的主要渔获种类从1967-2004年的产量均呈上升趋势,但产量的峰谷变化各不相同;空间分布特征研究表明,尽管在印度洋海域分布范围广泛,但产量丰沛的区域存在明显差异。

Main species caught by tuna longline fisheries and their distribution in the Indian Ocean

According to the tuna catch database established by Indian Ocean Tuna Commission （IOTC）, which covers the time from 1967 to 2004, the annual and the total catch in each spatial grid of 5°×5°were summarized. In addition, the maps of total catch distribution of the Indian Ocean tuna long-line fishing were plotted using GIS software, and the spatial distribution of tuna were analyzed. The analysis showed that big-eye tuna Thunnus obesus, yellow-fin tuna T. albacares, albacore T. alalunga and swordfish Xiphias gladius were the main species caught by tuna longline fisheries in the Indian Ocean, which comprised 90% of the total catch weight. Although the catch weight of the four main species in the Indian Ocean showed a trend of increase from 1967 to 2004, the maximum and minimum productions were different. Though the four species distributed widely in the Indian Ocean, their top catch areas were widely differ- ent.