南黄海及长江口附近海域绿潮暴发前期微观繁殖体的动态变化

The dynamics of micro-propagules before the Green tide(Ulva prolifera)outbreak in the Southern Huanghai Sea and Changjiang(Yangtze) River Estuary area

基于2011年3至5月对南黄海及长江口附近海域的水体与沉积物样品采集及实验室萌发培养实验,分析了绿潮暴发前期该海域微观繁殖体的时空分布特征。结果表明,在调查期间,南黄海水体中微观繁殖体空间分布趋势表现为近岸高远岸低,高值区主要集中在紫菜筏架养殖区附近海域,在122°30′E以东区域未发现有微观繁殖体存在。3,4,5月份该区域海水中平均微观繁殖体数分别为144,164和140株/dm3,最大值分别为278,426,和537株/dm3;南黄海沉积物中微观繁殖体数量分布范围介于19～127株/层,表层微观繁殖体数高于底层。长江口以北靠近江苏近岸区域有微观繁殖体存在,数量介于1～10株/dm3,31°N以南区域和河口内未发现有繁殖体分布,由此可排除黄海浒苔等绿藻微观繁殖体由长江水携带入海或来源于长江口南部海域。在春季绿潮暴发前开展该海域微观繁殖体的研究,可为查明绿潮发源地及早期发生发展过程提供基础资料,为预测和预警绿潮发生提供科技支撑。

Based on the monthly surveys conducted in the Southern Huanghai Sea and Changjiang（Yangtze） River Estuary during March to May 2011,the temporal and spatial distribution features of green algae micro-propagules in water and sediment were studied.The results showed：the spatial distribution of micro-propagules in the waters increased gradually from inshore to offshore areas in the Southern Huanghai Sea.The high values were presented mainly in the adjacent Porphyra farming area,and no micro-propagules were detected to the east of 122°30′ E.The average densities of micro-propagules in March,April and May were 144,164 and 140 inds/dm3 respectively,and the corresponding maximum densities were 278,426 and 537 inds/dm3 respectively.The content of micro-propagules in sediments ranged from 19 to 127 inds per layer,and this decreased with depth.Low density of micro-propagules（1-10 inds/dm3） were detected to the north of the Changjiang（Yangtze） River Estuary along the Jiangsu coast,while no micro-propagules were observed in the stations to the south of 31°N.Therefore,we could exclude the possibility that the green tide algae were carried into the sea by the Changjiang River or by the waters from south of the Changjiang（Yangtz） River Estuary.The research carried out,just before the breakout of green tide,was expected to predict the potential biomass of the green-tide Ulva species in seawater and provide technical support to green-tide control.