水母代谢过程中释放的溶解有机质的光谱特征  

Spectral Characteristics of Dissolved Organic Matter Released during the Metabolic Process of Small Medusa

作　　者：郭东晖[1] 易月圆[1] 赵磊[1] 郭卫东[1] 

机构地区：[1]近海海洋环境科学国家重点实验室,厦门大学海洋与地球学院,福建厦门361005

出　　处：《光谱学与光谱分析》2012年第6期1584-1587,共4页Spectroscopy and Spectral Analysis

基　　金：国家(973计划)项目(2011CB403604;2011CB409804);国家自然科学基金项目(40776041);中央高校基本科研业务费专项资金项目(201112G011)资助

摘　　要：研究了实验室培养的小型水母弗洲指突水母(Blackfordia virginica)代谢过程中所释放的溶解有机物(DOM)及其吸收和荧光光谱特征的变化。与对照组海水相比,充分摄食后的水母在24h的代谢过程中向水体释放大量的溶解有机碳和总溶解态氮,有色溶解有机物的吸收系数a280也有显著增加。光谱斜率比值(SR)的增大和腐殖化指数(HIX)的降低,表明水母代谢产生的主要是腐殖化程度较弱的低分子量DOM。利用平行因子分析(PARAFAC)模型对三维荧光光谱进行解谱,识别出3个类腐殖质(C1-C3)和1个类蛋白质(C4)组分。发射波长在400nm以下的"海源"类腐殖质组分C2(<250,295/386nm)及类蛋白质组分C4(275/334nm)在代谢过程中有明显增加,表明它们是水母代谢释放的主要荧光物质;而发射波长在400nm以上的组分则变化不大。据此可将发射波长小于400nm与大于400nm的荧光组分强度和之间的比值,构建为DOM的浮游动物来源指标(ZIX),用于识别和示踪水环境中浮游动物代谢活动释放和产生的DOM。The metabolic processes of jellyfish can produce dissolved organic matter（DOM） which will influence the functioning of the aquatic ecosystems,yet the optical properties of DOM released by jellyfish are unknown.Here we report the absorption and fluorescence properties of DOM released by a medusa species Blackfordia virginica during a 24 h incubation experiment.Compared with the control group,an obvious increase in the concentrations of dissolved organic carbon（DOC）,absorption coefficient（a280） and total dissolved nitrogen（TDN） was observed in incubation group.This clearly demonstrated the release of DOM,chromophoric DOM（CDOM） and dissolved nutrients by B.virginica which feed on enough of Artemia sp.before the experiment.The increase in spectral slope ratio（SR） and decrease in humification index（HIX） indicated that the released DOM was less-humified and had relatively lower molecular weight.Parallel factor analysis（PARAFAC） decomposed the fluorescence matrices of DOM into three humic-like components（C1-C3） and one protein-like component（C4）.The Fmax of two components（C2： 250,295/386 nm;C4： 275/334 nm） with the emission wavelength 400 nm increased significantly during the metabolic process of B.virginica.However,the Fmax of the other two components with the emission wavelength 400 nm showed little changes.Thus,we suggested a zooplankton index（ZIX） to trace and characterize the DOM excreted by metabolic activity of zooplankton,which is calculated as the ratio of the sum of Fmax of all fluorescence components with the emission wavelength 400 nm to the sum of Fmax of the other components with the emission wavelength 400 nm.

关 键 词：溶解有机物 水母 代谢过程 三维荧光光谱 平行因子分析 浮游动物源指标 

分 类 号：O657.3[理学—分析化学]