2009年至2016年华南近海赤潮分布特征

Characteristics of Red Tide in Coastal Region of South China from 2009 to 2016

本文对2009年至2016年间南海近岸海域发生的赤潮进行了分析,研究近岸海域赤潮爆发的时间规律,空间分布特征,初步探讨了赤潮种类的分布特性。结果表明,华南近海赤潮整体高发期集中在春季海水水温上升期,甲藻赤潮在南海赤潮中所占的比例达79%,且在南海近岸广泛分布,而硅藻出现次数较少,分布范围较窄。同时初步探讨了爆发硅藻赤潮为主的湛江港和爆发甲藻赤潮为主的大鹏湾内,水体环境和赤潮的关系:湛江港内水体中可溶性无机氮和无机磷含量长期处于赤潮富营养阈值,氮磷比在4至37之间,中肋骨条藻(Skeletonema costatum)集中在春夏水温较高时期爆发赤潮;而大鹏湾水体中可溶性无机氮和无机磷含量均为超过富营养阈值,夜光藻(Noctiluca scintillans)集中在冬季和初春水体温度较低时爆发赤潮,不同的温度变化和氮磷含量是导致2个海湾赤潮种类差异较大的重要因素。

Statistics analysis of red tide off-shoreof South China from 2009 to 2016 was executed to study the specificity of red tide species, geographical and temporal characteristics. It is showed that the red tide is intensively explored in spring, when the sea water temperature is increased. 79% of the red tide in the coastal region of South China was generated by dinoflagellate, and aggregated mainly around the off-shore area. However, diatom was found occasionally and with limited distribution range. In order to reveal the regularity of red tide exploration in Zhanjiang Harbor and Dapeng Bay, especially for Skeletonema costatum and Noctiluca scintillans, the temperature, ratio of inorganic nitrogen and phosphorus concentration were selected for analyses. The N：P ratio is from 4 to 37, which is beneficial for Skeletonema costatumred tide exploration in Zhanjiang harbor. And it usuallytook place in spring and summer, when sea water was warm. Noctiluca seintillans red tide usually explored in Dapeng Bay, where the inorganic nitrogen and phosphorus concentration in sea water exceeded eutrophication threshold. Noctiluca scintillans is easily to be found when sea water temperature was relatively low, such as in early spring or in winter. It is believed that the discrepancy of different red tide species was caused by the changes in sea water temperature, inorganic nitrogen and phosphorus concentration in these two waters.