青岛海域漂浮浒苔光合生理特性及藻体状态等级评价研究

Studies on photosynthetic physiological characteristics and grade evaluation for free-floating algae( Ulva prolifera) along Qingdao coast

研究了黄海青岛海区漂浮绿潮藻浒苔（Ulva prolifera）的光合生理特性并进行状态等级评价，为今后黄海绿潮暴发趋势预警预测和生长潜力评估奠定基础。首先根据藻体状态对应其最大光量子产量（Fv/Fm）的差异，初步将藻体分为4个等级：Ⅰ级健康藻体，藻体呈绿色（G），Fv/Fm为0.70~0.75；Ⅱ级亚健康藻体，藻体呈黄绿色（GY），Fv/Fm为0.60~0.69； Ⅲ级半健康藻体，藻体呈黄色（Y），Fv/Fm为0.41~0.59；Ⅳ级衰老藻体，藻体呈白色（W），Fv/Fm为0~0.40。对2011年青岛近岸海域的漂浮浒苔藻体状态等级进行测定和评价，发现各采样点藻体处于以下3个不同等级：Ⅱ级亚健康藻体，其Fv/Fm最高仅0.68，总叶绿素含量为（0.608±0.032） mg/g；Ⅲ级半健康藻体,其Fv/Fm最高为0.57，总叶绿素含量为（0.226±0.031）mg/g；Ⅳ级衰老藻体，其Fv/Fm最高仅为0.29，总叶绿素含量为（0.088±0.029） mg/g。其中，QD1、QD2、QD3主要以Ⅲ级（51.34%~71.37%）和Ⅳ级藻体（17.84%~28.08%）为主；而QD4、QD5、QD6主要以Ⅲ级藻体为主（95.13%以上）。表明漂入青岛海域绿潮藻浒苔大部分状态较差，不能健康存活。另发现浒苔藻体叶绿素含量高低与光合活性呈正相关（F=25.106,R=0.782,P〈0.01），为探索两者耦合关系以及今后完善藻体状态评价体系提供依据。

In this paper, for laying the foundation in future for the forecast and potential evaluation of green tide occurrence in the Yellow Sea, the photosynthetic physiological characteristics parameters and grade evaluation of free floating algae,Ulva prolifera drifting along Qingdao coast were studied. According to the difference of algae physiological states corresponding to the maximum light quantum yield （Fv/Fm）, the floating Ulva proliferaare divided into four categories： Grade I： green healthy algae （G）, the range of Fv/Fm value is from 0.70 to 0.75; Grade Ⅱ： green yellow sub health algae （GY）, the range of Fv/Fm value is from 0.60 to 0.69; Grade Ⅲ： yellow ill health algae （Y）, the range of Fv/Fm value is from 0.41 to 0.59; Grade IV： white decayed algae （W）, the range of Fv/Fm value is from 0 to 0.40. The free floating algae sampled at various sampling points along Qingdao coast in 2011 can be classified into the following three categories after the measurement and evaluation on the algae state： Grade Ⅱ, the highest Fv/Fm value was 0.68 corresponding to the total chlorophyll content was （0.608±0.032） mg/g; Grade Ⅲ, the highest Fv/Fm value was 0.57 corresponding to the total chlorophyll content was （0.226±0.031） mg/g; Grade IV, the highest Fv/Fm value was 0.29 corresponding to the total chlorophyll content was （0.088±0.029） mg/g. Furthermore, the healthy levels of floating thalli were mainly composed of Grade Ⅲ （51.34% 71.37%） and Grade IV （17.84% 28.08%） in QD1 3 sampling points, and were predominated by Grade Ⅲ （above 95.13%） in QD4 6 sampling points, indicating that most free floating green tide algae could not survive in Qingdao coast. In addition, the results showed that the chlorophyll content was in direct proportion to the photosynthetic activity of U. prolifera（F=25.106,R=0.782,P〈0.01）, which provides a basis to explore the coupling relationship and consummate the evaluation system in the future.