Controls on the Isotopic Composition of Phytoplankton

9633091 POPP海洋浮游植物的碳同位素组成不仅反映了海水的同位素组成，而且反映了发生光合作用的环境条件。海洋学家和古生物学家特别感兴趣的是浮游植物的同位素组成与环境温度的关系，以便保存在海洋沉积物中的化石有机质可能被用来推断过去地质时代的气候条件。由于实际发现的藻类同位素组成是由多种因素造成的，因此有必要了解它们各自和集体的影响。夏威夷大学和斯科舍海洋研究所的这个研究小组将利用实验室和实地研究来研究生理状态、生长速度和环境条件等条件如何影响浮游植物的碳同位素分馏。实验室研究将涉及对两种藻类的仔细培养工作，结果将与从阿拉伯海的水柱和沉积物以及瓦胡岛附近的夏威夷海洋时间序列站收集的样本进行比较，使用将各种生理和环境因素与藻类同位素组成联系起来的数学模型。

9633091 POPP The isotopic carbon composition of the marine phytoplankton reflects not only the isotopic composition of seawater but also the environmental conditions under which photosynthesis occurs. Oceanographers and paleontologists are particularly interested in how phytoplankton isotopic composition is related to ambient temperature so that fossil organic matter preserved in marine sediments might be used to infer climatic conditions in the geologic past. Because variety of factors is responsible for the algal isotopic composition actually found, there is a need to understand their individual and collective impact. This research team from the University of Hawaii and the Scotia Institute of Oceanography will use laboratory and field studies to examine how conditions such as physiological state, growth rate, and environmental conditions affect carbon isotopic 'fractionation' by the phyplankton. The laboratory studies will involve careful culture work with two algal species, and the results will be compared to samples collected from the water column and sediments of the Arabian Sea and at the Hawaiian Ocean Time-Series station near Oahu using a mathematical model relating various physiological and environmental factors to algal isotopic composition.