黄海鳀鱼时空分布季节差异分析

Seasonal dissimilarity of Engraulis japonicus spatiotemporal distribution in Yellow Sea

利用1986—2010年的底拖网调查数据,基于GIS的空间分析和地统计分析技术,从不同角度阐明在捕捞压力和气候变化的双重胁迫下,黄海鳀鱼资源密度时空分布及其变动的季节差异。结果表明:不同季节鳀鱼空间分布趋势变化明显,冬季,资源密度从调查区域东北部向岸边和南部水域递减,春季,与冬季相反,资源密度由岸边向东部水域递减,夏季,整体上资源密度呈北高南低的趋势,但高值点散乱分布,秋季,与冬季相似,资源密度由东部水域向岸边环形递减,但变化梯度较冬季缓和;鳀鱼资源密度重心季节变化明显,但不同年代变化规律并不相同;1986—2010年,春、夏和秋3个季节,鳀鱼资源密度重心均向北移动,冬季,资源密度重心年间变化明显,但无整体迁移规律;不同季节,鳀鱼资源密度高值聚集区空间分布位置不同。

Based on the bottom trawl survey data in 19862010, and by using the techniques of GIS spatial analysis and geostatistics, this paper studied the spatiotemporal distribution and its seasonal dissimilarity of anchovy （Engraulis japonicus ） stock density in Yellow Sea under the double stress of fishing pressure and climate change. There existed obvious variations in the spa tial distribution of the anchovy in different seasons. In winter, the stock density of the anchovy decreased gradually from the northeastern waters to the shore and southern waters; in spring, the stock density decreased gradually from the shore to the eastern waters; in summer, the stock den sity had a trend of decreased from the northern waters to the southern waters, but the high value points scattered; in autumn, similar to that in winter, the stock density decreased from the east ern waters to the shore, but the variation gradient was smaller than that in winter. The stock den sity center of the anchovy had an obvious seasonal variation, but the variation pattern differed with years. From 1986 to 2010, the stock density center of the anchovy moved northward in spring, summer and autumn, and had an obvious yearly transformation but no overall migration trend in winter. In different seasons, the aggregation areas of the anchovy＇ s high stock density differed spatially.