中文摘要：

球形棕囊藻是一种具有复杂异型生活史的有毒有害赤潮生物,近年来在我国近海频繁暴发成灾,形成的巨大囊体为国内外罕见。迄今还未见到有效消除囊体型球形棕囊藻赤潮的方法报道。本文通过海上围隔实验和现场赤潮消除工程跟踪监测,考察了喷洒改性黏土消除囊体型球形棕囊藻赤潮的可行性与效率,并分析了改性黏土法治理赤潮时对水体及沉积环境的可能影响。围隔实验结果表明,喷洒改性黏土可以有效消除水体中过量的微藻细胞,其中以少量多次喷洒方法的效果最好,生物量（chl a）去除率〉90%。在对2016年2月广西防城港附近海域球形棕囊藻赤潮消除时的跟踪监测结果表明,改性黏土法适用于工程化消除赤潮作业,能够快速消除水体中的大量球形棕囊藻囊体,随改性黏土絮凝体沉入海底的赤潮藻可以快速分解而失去活性。喷洒改性黏土对于赤潮水体的主要理化指标影响不显著,所监测的水体COD、pH和不同形态氮、磷、硅等生源要素浓度都在原有水质水平范围内波动。

英文摘要：

Phaeocystis globosa has a polymorphic life cycle. It is a toxic phytoplankton species which can form colonies and bloom into eco-disasters in the worldwide seawaters. P. globosa blooms frequently occurred along the south China coasts in recent years. These colonies are over several centimeters in diameter, and is much larger than those reported in other oceans. No previous reports are made about how to mitigate effectively P. globosa blooms. In this study, we tested the efficiencies of the colony removal and the environmental effects of different modified clays（MCs） in the field mesocosm and a bloom mitigation. Results of our mesocosm experiments showed that it was efficient to remove P. globosa blooms by spraying MCs, which presented algal biomass removal efficiencies of more than 90%, and the better efficiency was achieved by frequent spraying MCs at small dosages. Spraying MCs was also effective for removing colonies of P. globosa blooms in the Fangchenggang coast. Analysis of algal pigments in sediments showed that MCs could effectively settle and lyse P. globosa cells after they were coagulated. Notably, the impact of MCs on COD, pH and concentrations of different forms of nitrogen, phosphorus and silicon in the bloomed water was minimum and the variations of these parameters were within the range of water quality.