近10年珠江口海域赤潮发生特征及原因初探

对2000-2009年珠江口海域发生的各种赤潮灾害资料进行统计分析,研究珠江口海域赤潮发生的时空分布规律、赤潮种类的变化规律、海水营养限制的变化状况.结果表明,珠江口赤潮多发区为深圳湾海区,近年珠江口西部珠海沿岸海域频发大面积赤潮;赤潮灾害发生的持续时间呈上升趋势;赤潮多发种为中肋骨条藻,多发于深圳湾;定鞭藻类原球形棕囊藻引发的有毒赤潮明显增多且影响范围较大.研究发现,珠海沿岸海域频发大面积赤潮和深圳湾春季频发赤潮可能与出现潜在硅酸盐营养限制有关,冬季频发球形棕囊藻与季节骤然升温有关.

10-year?retrospective?analysis?on?the?harmful?algal?blooms?in?the?Pearl?River?Estuary

Based on the historical analysis of accumulated 10 years’ data on the harmful algal blooms(HAB) in the Pearl River Estuary,the paper has made a comprehensive study on the HAB.It studied the regularity of the HAB distribution and the succession of causative organisms as well as the status of nutrient limitation.The result of the study and analysis indicated that the frequent occurrence area of HAB was Shenzhen Bay.Intensive bloom events of HAB occurred in the western coasts of the Pearl River Estuary,and the annual blooming period tended to rising significantly.The most causative species of HAB was Skeleton costatum and usually bloomed in Shenzhen Bay.In addition,toxic events turned up more and more frequently.The blooms of Haptophyceae(such as Phaeocystis globasa ) increased and the areas affected by Phaeocystis globasa blooming events extended.According to the data,one of the influential factors for the occurrence of HAB in Zhuhai coastal area and Shen-Zhen Bay was the potential limitation of silicate content in the sea water,and the key factor causing the bloom of Phaeocystis globasa in the Pearl River Estuary was the sudden rising of temperature in winter.