1999年7月胶州湾东部赤潮生消过程生态环境要素分析

Analysis of the Ecological Environment Elements in the Red Tide Generating and Vanishing Process in the Eastern Jiaozhou Bay in July, 1999

根据 1 999年 7月 2 3 - 2 4日胶州湾东部赤潮发生海区的观测资料 ,结合同年 6 ,7,8月3个航次的数据 ,分析了赤潮前后水体浮游植物群落、叶绿素 a和营养盐等要素的变化特征。结果显示 ,本次赤潮为短角弯角藻 (Eucampia Zoodiacus)赤潮 ,总生物密度高达 1 .6× 1 0 10个 /m L。赤潮发生时 ,叶绿素 a浓度范围为 2 8.8～ 3 6 .0 mg/m3 ;温度、盐度变化不大 ,DO,p H值升高 ,营养盐浓度处于较低水平 ,其中 P降幅最大 ,N/P值则急剧上升 ,峰值为 2 4 7,P被认为是本次赤潮的限制因子 ;NO2 - N/NO3 - N的值变化很大 ,高于正常值。赤潮消退 。

Based on the data observed in the eastern Jiaozhou Bay red tide area during July 23 to 24, 1999 and the data observed in June, July and August, 1999, the variations in ecological elements, including phytoplankton community, chlorphyll-a and nutrients in the seawater before and after the red tide occurrence were analysed. It is shown from the analysis results that this red tide is an Eucampia Zoodiacus red tide with a high total cell concentration of 1.6×10 10 cells/mL. When the red tide occurred, the chlorophyll-a ranged 28.8 mg/m 3 to 36.0 mg/m 3, the changes in temperature and salinity were not great, the DO and pH values increased; the concentrations of nuutrients, especially phosphate, decreased to result in a drastic increase in N/P value with a peak N/P value of 247, and P is considered as the limiting factor for this red tide; the NO 2-N/NO 3-N fluctuated greatly and reached an abnormally high value. When the red tide had disappeared,the above ecological elements returned to normal again.