基于光谱相似性指数的赤潮藻荧光识别技术

Fluorescence Discrimination Technology for the Red Tide Algae by Spectra Similarity Index

东海原甲藻(Prorocentrum dentatum)、裸甲藻(Gymnodinium stein)和中肋骨条藻(Skeletonema costatum)是近几年我国东海频繁引发赤潮的藻种。基于这三种赤潮藻的活体叶绿素荧光激发光谱,通过计算光谱相似性指数对其进行识别。结果表明,活体叶绿素荧光激发光谱在平行测量和不同生长期的相对标准偏差(RSD)分别小于3%和5%;光谱混合及混合海藻荧光光谱与标准谱之间的光谱相似性指数与混合比例之间存在线性关系。通过计算混合藻的荧光光谱与标准谱之间的相似性指数能够定性地识别引发赤潮的藻种,并半定量地估计赤潮藻种的相对含量。当噪声小于25%时,噪声基本不会对赤潮藻的识别分析产生影响。

Prorocentrum dentatum, Gymnodinium stein and Skeletonema costatum are the main algae which frequently cause red tide. In this paper in vivo fluorescence excitation spectra were measured and the discrimination method of the red tide algae was established by the similarity index of spectra. The results show that the in vivo fluorescence excitation spectra were well reproduced （RSD≤5%） and the spectra precision was very high （RSD≤3 %）. The similarity index between the standard spectra of one algae species and hypothetical mixed spectra of algae and spectra of mixed algae assemblage was calculated. There is a linear relationship between the similarity index and the relative content of the algae. So the red tide algae can be discriminated by calculating the similarity index between fluorescence spectra of mixed algae and their standard fluorescence spectra, and the relative content of the red tide algae can also be detected semi quantitatively. There is almost no influence of noise on the discrimination of red tide algae when noise is lower than 25 %.