| 摘要: |
| 海洋酸化是近年来人类所遇到的重大全球环境问题之一，它指的是大气CO2浓度增加引起的海水pH降低的现象。海洋酸化已经威胁到珊瑚礁及其它钙质生物的生存与发展。近期的预测模型与野外实验均表明，海洋酸化的后果可能比以前想象的更为严峻。本研究采用叶绿素荧光技术，选取3种鹿回头珊瑚礁区常见的珊瑚种类（Acropora valida、Galaxea astreata和Favites abdita），分别设置海水环境为450 μatm、650 μatm（IPCC预测的2065年的水平）和750 μatm（IPCC预测的2100年的水平）的3个pCO2浓度梯度，监测珊瑚在不同CO2浓度背景下10天内的光合荧光参数的变化。实验结果表明，水体pCO2为650μatm时，珊瑚的总体光合效率最高，但随着时间的延长，珊瑚荧光参数在3个浓度梯度下都会显示不同程度的下降趋势。虽然3种珊瑚对不同浓度CO2响应的程度不同，但基本上显示出，在低浓度pCO2时，pH下降引起的酸化作用控制着珊瑚共生藻的光合效率；而随着浓度的增加，CO2增加引起的施肥效应愈加明显，与酸化作用竞争，共同作用于珊瑚共生藻，使得光合荧光参数在波动中变化。 |
| 关键词: 海洋酸化 pCO2 造礁珊瑚 光合效率 酸化效应 施肥效应 |
| DOI：10.11693/hyhz20121221001 |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目），国家重大科学研究计划课题 |
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| Experimental study on the impact of ocean acidification on photosynthesis efficiency of symbiotic zooxanthellae of corals |
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Zhou Jie,Yu Ke-fu and Shi Qi
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South China Institute of Oceanology, CAS,South China Institute of Oceanology, CAS,South China Institute of Oceanology, CAS
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| Abstract: |
| Ocean acidification, referred to the phenomenon of the lowering of ocean pH, which is caused by the increase of concentration of CO2 at atmosphere, is one of the global environmental threat in recent year. The phenomenon has already threatened coral reefs and calcifying organisms. It is indicated by latest forecast models and field data, that the concequences caused by ocean acidification may be much more severe than was forecast previously. The objectives of this short-term study were to investigate the viability of three ecologically important reef-building coral species, Acropora valida , Galaxea astreata and Favites abdita, exposed to high pCO2 conditions and to observe possible changes in physiologically related parameters. Fragments of corals were kept for 10 days under controlled aquarium conditions characterized by elevated pCO2 conditions, i.e. pCO2 values of 450 μatm, 650 μatm and 750 μatm. Fluorescence analysis showed that the gross photosynthetic efficiency was highest when the pCO2 of seawater was 650 μatm. During the 10-day experiments, with the time in the acidified seawater goes on, the fluorescence parameters have the tendency of decreasing in diverse degree. Though the responses of three kinds of corals were not agreed with each other, it is suggested that when pCO2 is low, acidification effect, which controls the changes of zooxanthellae, is stronger than fertilization effect induced by increasing CO2. As the pCO2 increases, the fertilization effect, which becomes apparent, competes with acidification effect and takes effect on corals, leading to the variations of fluorescence parameters. |
| Key words: ocean acidification, pCO2, scleractinian coral, photosynthetic efficiency, acidification effect, fertilization effect |
