秋季东海北部和黄海南部沙海蜇资源分布及其与底层温盐度的关系

根据2006～2009年秋季在东海北部和黄海南部对沙海蜇(Nemopilema nomurai)和温盐度的同步监测数据,对秋季沙海蜇的资源分布特点及其和底层温盐度的关系进行了研究。结果表明:秋季东海北部和黄海南部沙海蜇的高生物分布区主要集中在以下3个海域:(1)南黄海西侧浅水海域;(2)南黄海中央深水区(32°30'N～34°00'N、123°00'E～124°30'E);(3)大沙和长江口外海水域。前2个高生物量分布区某些年份会连成一片,第二个高生物量区基本上每年都会出现,第三个高生物量区某些年份可能不会出现。结合底层温盐度的分布特征,可以看出:沙海蜇高生物量区主要出现在黄海冷水团的前缘或冷暖水团的交汇处,且在冷暖水团的交汇处,更易形成高生物量聚集。而在暖水团控制的海域内,其生物量较低,在垂直分布上,沙海蜇可能主要活动区域在30 m以深的水温相对较低(低于15℃)且变化幅度较小、盐度处于中盐水平(32.0～33.5)的水体内。

Distribution of Nemopilema nomurai and its relationship with bottom temperature and salinity in north East China Sea and south Yellow Sea in autumn

Based on the simultaneous monitoring data of Nemopilema nomurai and water temperature and salinity in the north East China Sea and south Yellow Sea in autumn from 2006 to 2009,the resource distribution of Nemopilema nomurai and its relationship with bottom temperature and salinity were studied.The results showed that: Nemopilema nomurai distribution area of high bio-concentration were in the following 3 sea waters in the investigated areas in autumn:(1) shallow water district in western part of south Yellow Sea;(2) deep water district in the central of south Yellow Sea(32°30′N-34°00′N,123°00′E-124°30′E);(3) off-the-coast water district of DaSha and the Yangtze River estuary.The former two high-biomass distribution areas were connected into one in some years,and the second appeared basically every year and the third area of high biomass may not appear in some year.Combination of the distribution characteristics of bottom water temperature and salinity could show:areas of high biomass Nemopilema nomurai were mainly in the front of Yellow Sea cold water mass or the junction of cold and warm water masses,it was more likely to form high biomass accumulation in the interchange areas of cold and warm water masses,but in the water areas controlled by warm water mass,the biomass was lower.In the vertical distribution,Nemopilema nomurai may be mainly live beyond 30 m deep water,where temperature was relatively low(below 15 ℃) and temperature changes were slight,and the salinity level was in the middle(32.0-33.5 psu).