秘鲁外海茎柔鱼渔场时空分布分析

Spatial and Temporal Distribution of Fishing Ground for Dosidicus gigas in the Offshore Waters of Peru

秘鲁外海茎柔鱼是重要的经济性种类,掌握其渔场时空分布规律有助于资源的合理利用。本文根据2003—2004年和2006—2009年我国鱿钓船在秘鲁外海的生产统计和海洋表面温度(SST)等资料,使用空间距离和聚类分析的方法,对其各年间渔场时空分布进行分析比较。结果表明,各年产量重心的分布都存在一定差异,产量重心在经度上随月份整体上呈现向西移动的趋势,在纬度方向上1～6月整体上呈向北移动的趋势,7～12月则表现出向南移动的趋势。聚类分析表明,2003、2006和2008年;2004、2007和2009年空间分布格局各为一类。空间距离分析表明,2006和2009年产量重心差异最大,其中前者平均产量重心为82°23′W、12°53′S,后者为81°47′W、14°27′S,南北相差约1.5个纬度。研究认为,渔场分布的月间变化是由茎柔鱼南北洄游所引起的,年间渔场分布差异与SST等海洋环境关系密切。

Jumbo flying squid,Dosidicus gigas,distributed in the waters of Peru,is an important economic squid.Understanding of the spatial and temporal variations in the distribution of this squid is useful to rational utilization of its resources.In this study,based on the fishing data and sea surface temperature（SST） collected by Chinese squid fleets in the waters off Peru from 2003 to 2004 and from 2006 to 2009,the methods of spatial distance and aggregative analysis were used to study the spatial and temporal variations in fishing ground for Dosidicus gigas.The result indicated that there were some differences on the gravity between years.It was found that the position of longitude showed westward move with months,whereas its latitude showed northward shift from January to June and southward shift from July to December.The cluster analysis showed that four groups are divided,i.e.（2003,（2006 and 2008））,（2004,（2007 and 2009）） respectively.The results indicated that the gravities of catch between 2006 and 2009 are different.The former＇s weight position of catch is 82°23′W and 12°53′S and the latter＇s weight position of catch is 81°47′W and 14°27′S,which have 1.5 degrees of latitude difference.The results showed that the monthly difference in fishing ground may be caused by the migration of jumbo flying squid,and the annual difference in fishing ground may be related to the changes of marine environment.