利用围隔实验研究赤潮过程中藻细胞荧光能力

2002年5月和2003年5月在东海赤潮现场进行了添加营养盐诱发赤潮的船基围隔实验。通过测定赤潮藻活体荧光和DCMU增强荧光研究赤潮生消过程中藻细胞荧光能力的变化,揭示在赤潮形成阶段的藻细胞增长期细胞荧光能力较强,反之,在赤潮消亡过程中随着生物量和叶绿素a下降,细胞荧光能力也随之下降。不同围隔中生物量和叶绿素a有较大差别,而细胞荧光能力差别不大。这说明细胞荧光能力的大小与生物量无关,而是取决于藻细胞的生理状况。各围隔中加入DCMU后的增强荧光与正常荧光之间的差值(Fd-F)在赤潮发展过程中均增大,在赤潮消亡过程中均减小。根据它的大小和细胞荧光能力可初步判定赤潮是处于发展过程还是消亡过程。

Study of Algal Cellular Fluorescence Capacity in Red Tide Process Using Mesocsm Experiment

During May 2002 to May 2003,ship-based mesocosm experiments were conducted to study the role of nutrients in the red tide process in the East China Sea,and the variations of cellular fluorescence capacity(CFC) of red tide algae in the red tide process was studied by measuring in vivo fluorescence F and DCMU induced fluorescence F_d.It is shown from the study results that the CFC was higher in the red tide formation stage,and the CFC decreased with decreasing bimass and chlorophyll-a in the red tide moribund stage,Although there was big difference in bimass and chlorophyll-a between different mesocosms,there was no fignificant difference in CFC,which indicates that the CFC of algal cells is independent of bimass,and is dependent on the physiological conditions of algal cells.The difference between DCMU induced fluorescence and in vivo fluorescence(F_d-F) increased in the red tide development process and decreased in the red tide moribund process,so the value of F_d-F can be used to preliminarily determine whether the red tide is in the development process or in the moribund process.