赤潮过程中塔玛亚历山大藻(Alexandrium tamareme)C、N稳定同位素组成的变化规律

为了探索赤潮监测预防的新思路和方法,本研究选取典型赤潮藻(塔玛亚历山大藻Alexandrium tamareme)作为实验藻种,模拟一次完整的赤潮形成过程,测定重要监测指标(生物量、营养盐浓度)的变化,找出稳定同位素特征值与之相关变化规律。实验结果表明,藻种生长过程可明显分为四个阶段:适应期、对数生长期、稳定生长期及衰亡期;N、P浓度随培养时间呈下降趋势,与生物量的变化有很好的相关性,但在生长过程中几乎不吸收硅酸盐。在一次完整的赤潮发生过程中,C稳定同位素组成(13C值)随时间显示出减小趋势,而N稳定同位素组成(15N值)值则显示增大趋势。因此,赤潮藻的C和N稳定同位素组成为赤潮监测提供了可能的新指标和新方法。

Variation of carbon and nitrogen stable isotope composition of Alexandrium tamareme in the process of red tide

In order to explore a new method for the red tide monitoring, this study selected one of the typical red tide algae, Alexandrium tamareme, as experimental material.We simulated a complete algal bloom process and examined the important monitoring index (biomass, nutrient concentration), find out the rule of the correlation with stable isotope characteristic value.The results show that algae growth process can be obviously divided into four stages:the adaptation period, the logarithmic growth phase, stable growth phase and decline phase;N, P nutrient concentration decreased with the incubation time, there is a good correlation with the change of biomass in the growth process, but almost no absorption of silicate.In a complete algal bloom process, the stable carbon isotope composition (13C) shows decrease tendency, while the stable nitrogen isotope composition (15N) reveals increase tendency.Therefore, the stable isotope composition can provide new indexes and possible new methods for the red tide monitoring.