胶州湾浮动弯角藻赤潮生消过程

A RED TIDE CAUSED BY DIATOM EUCAMPIA ZOODIACUS IN THE JIAOZHOU BAY

根据 1 999年 6月中旬胶州湾东北部养殖水域浮动弯角藻 (Eucampia zoodiacus)赤潮的监测资料 ,分析讨论了赤潮生消动态过程中浮游植物种类组成、密度、Chl.a及水文化学要素的变化特征。结果表明 ,本次赤潮高峰持续时间为 3天 ,面积约为 1 5 km2 ,赤潮原因种为浮动弯角藻 ,密度变化范围为 5 2× 1 0 6— 1 0 2 8× 1 0 6个 /m3 ,Chl.a变化范围为 1 .5 3—3 2 .2 8mg/m3 ,浮游植物密度变化范围为 4.0× 1 0 6— 7.7× 1 0 8个 /m3 ,赤潮过程中浮游植物种类组成更替明显 ;水文化学等要素亦有较大变化 ,海水呈棕褐色 ,透明度范围为 0 .1— 0 .3 m,温度范围为 2 0 .4— 2 4 .8℃ ,盐度范围为 2 9.4— 3 2 .9,DO、COD均出现异常增高现象 ,营养盐含量有不同程度下降 ,其中铵态氮、磷酸盐、硅酸盐降幅明显 ,成为后期限制赤潮种生长、繁殖的重要因素 。

In June 1999,a red tide occurred in a marine aquaculture site,northeast of the Jiaozhou Bay with Eucampia zoodiacus being the causative species Phytoplankton composition,phytoplankton density,chlorophyll a and other environmental factors were measured during the red tide period The whole event lasted for 3 days in an area of about 15km 2 The color of seawater was brown and the transparency varied from 0 1 to 0 3 meter during the bloom The ranges of total phytoplankton density, E zoodiacus density and chlorophyll a were respectively 4 0×10 6-7 7×10 8cells·m -3 ,52×10 6-1028×10 6cells·m -3 ,and 1 53-32 28mg·m -3 DO,COD and pH were enhanced significantly during the event The rapid increases of nutrients caused by the drainage after rain was the main contribution to the occurrence of the bloom and the depletion of nutrients was assumed to cause the red tide to disappear