具齿原甲藻的生态特征及赤潮成因浅析

Ecological characteristics of Prorocentrum dentatum and the cause of harmful algal bloom formation in China Sea

在东海的长江口和舟山海域 ,2 0 0 0～ 2 0 0 2年连续 3年的 5月发生罕见的大规模赤潮 ,赤潮生物为具齿原甲藻 ,为了解该种的生态特征及赤潮频发原因 ,本文分析近年赤潮应急监测资料及野外生态调查资料 ,结果表明 ,该种适温、适盐范围分别为 15～ 2 5℃和 14～ 32 ,最适温度、盐度分别为 18～ 2 2℃和 2 2～31.该种运动能力较强 ,在海流交汇的紊乱水体中具有强适应能力 ,具有昼夜垂直移动特性 .水温、硝酸盐含量、海流及上升流、磷限制环境下的种间竞争优势对诱发和维持赤潮具有重要作用 .

Large-scale harmful alga bloom (HAB) has been found in Changjiang River estuary and Zhoushan archipelago in recent three years, and the alga is Prorocentrum dentatum, which distributes in the sea areas with high salinity and (may) originates in outer sea area. Data from recent HAB rapid monitoring and ecological investigation were analyzed to study its ecological characteristics and forming inducement. The results showed that the most suitable temperature and salinity range for HAB forming was from 18℃ to 22℃ and from 21 to 31, respectively. The P. dentatum was motile and owned diurnal vertical migration bringing them the advantages in obtaining light and nutrients.Eutrophication was the preliminary condition, and water temperature,nitrate content, upwelling current,and strong competence on low phosphate environment were important to cause and maintain HAB.