| 摘要: |
| 长江口邻近海域是我国近海有害藻华高发区之一。受长江冲淡水和台湾暖流影响，海域环境条件复杂，有可能影响到藻华的分布状况、动态过程和危害效应。本文利用“藻华973项目”2011年的现场实测数据，从水体层化状况与藻华的关系入手，绘制出各要素的平面及剖面分布图，对比分析了春季硅藻藻华和甲藻藻华期间的温、盐跃层及其变化情况，探讨了硅、甲藻藻华的分布状况及其与温、盐跃层之间的关系。研究发现，2011年春季藻华期间该海域存在明显的温跃层和盐跃层。硅藻藻华期的温、盐跃层主要受到长江冲淡水影响；而在甲藻藻华期，受外海水入侵影响导致的温、盐跃层现象更加显著。藻华期间，浮游植物生物量高值区均出现在跃层上方的长江冲淡水影响区，其中硅藻藻华分布区与高强度跃层区基本一致，而甲藻藻华则主要分布在层化强度相对较弱的近岸海区，其分布可能受到上升流的影响。综合上述分析结果可以看出，长江口邻近海域春季的硅藻藻华主要受到长江冲淡水影响，而甲藻藻华的分布则在一定程度上受到外海水入侵及上升流影响。这一认识为进一步分析该海域春季硅、甲藻藻华演替过程及藻华优势种的长期演变趋势提供了新的思路和依据。 |
| 关键词: 长江口邻近海域 有害藻华 叶绿素a 温跃层 盐跃层 |
| DOI：10.11693/hyhz20160500115 |
| 分类号: |
| 基金项目:中国科学院先导专项（A类），XDA11020304号；国家重点基础研究发展计划（973）项目，2010CB428700号；国家自然科学基金，U1406403号。 |
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| RELATIONSHIP BETWEEN HARMFUL ALGAL BLOOMS AND WATER STRATIFICATION IN WATERS OFF CHANGJIANG RIVER ESTUARY |
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ZHOU Zheng-Xi1,2, YU Ren-Cheng1,3, LV Song-Hui4, GUAN Wei-Bing5, ZHOU Ming-Jiang1
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1.Key Laboratory of Marine Ecology & Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;2.University of Chinese Academy of Sciences, Beijing 100049, China;3.Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China;4.Institute of Hydrobiology, Jinan University, Guangzhou 510632, China;5.The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China
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| Abstract: |
| Coastal waters off Changjiang River estuary suffered from high-frequency of harmful algal blooms (HABs) in China in recent decade under complicated environmental conditions in which Changjiang Diluted Water (CDW) and Taiwan Warm Current (TWC) were active,the distribution,dynamics,and consequences of algal blooms were affected.Focusing on the potential effects of water stratification on algal blooms,an investigation was conducted and data collected during the cruises in 2011 as a part of the GEOHAB Ⅱ project.To understand possible link of the changes of thermocline and halocline to diatom or dinoflagellate bloom,distribution of different algal blooms and water stratification were studied.As our data show,the thermocline and halocline became apparent during spring blooms.Particularly,they cohered to the CDW for diatom bloom,to different ocean currents for dinoflagellate bloom.The phytoplankton biomass was boosted in the CDW above thermocline and halocline during spring blooms.Diatom blooms were found associated with strong stratification affected by CDW,while dinoflagellate blooms were with relatively weaker stratification in near-shore seawaters affected by upwelling and intrusion of Kuroshio.It was concluded that the CDW played an important role in affecting the distribution of diatom bloom in this region,while the dinoflagellate bloom was partially affected by the upwelling and intrusion of open sea waters.The results of this study may help further elucidate the different mechanisms of diatom blooms and dinoflagellate blooms,and to predict the long-term changes of HABs in this region. |
| Key words: Changjiang River estuary harmful algal blooms chorophyll a thermocline halocline |
