珠江口赤湾一次双相赤潮成因初探

对2002年6月4日至13日在珠江口赤湾至桂山岛一带海域发生的赤潮进行跟踪监测,并根据监测结果对赤潮生物与各水化要素进行相关性分析。结果表明,该次赤潮为无纹环沟藻(Gyrodimium instriatum)和中肋骨条藻(Skeletonema costa-tum)引起的双相赤潮。赤潮期间,两种赤潮生物与pH值和溶解氧的相关性不明显;无纹环沟藻个体数量与活性硅酸盐含量之间呈显著负相关关系,而与活性磷酸盐含量和无机氮含量之间相关关系不明显;中肋骨条藻个体数量与活性磷酸盐含量成明显负相关关系而与活性硅酸盐、无机氮含量之间相关关系不明显;富营养化是形成本次赤潮的基础,而主要赤潮生物(无纹环沟藻和中肋骨条藻)的交互演替,则与其相互之间存在的竞争关系有关。

A primary study on one of "bilateral" red tide at Chi Bay of Pearl River Estuary

From June 4th to 13th of 2002, a red tide occurred from Chi Bay to Gui Shan online of Pearl River Estuary. Based on the monitoring information, a correlation analysis between the amount of the predominant organisms causing the red tide and the main environmental factors was made. The results showed that the organisms causing the bilateral red tide were two kinds of algae, Gyrodinium instriatum and Skeletonema costatum. The results of correlation analysis also showed that during the course of the red tide, there were not obvious correlations between pH values and the amount of Gyrodinium instriatum , as well as Skeletonema costatum , the same as DO. There was a notably negative correlation between the amount of Gyrodinium instriatum and silicate, but a obvious relation was not found between phosphate and nitrate. There was a negative correlation between the amount of Skeletonema costatum and phosphate, but a obvious relation was not found between silicate and nitrate. It was concluded that the main for the red tide was the eutrophication in the marine area; and the succession between Skeletonema costa~ tum and Gyrodinium instriatum was correlated with the competition in two organisms.