The role of coccolithophore calcification in bioengineering their environment.
The role of coccolithophore calcification in bioengineering their environment.
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DOI：
10.1098/rspb.2016.1099
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发表时间：
2016-06-29
期刊：
影响因子：
--
通讯作者：
Wheeler G
中科院分区：
文献类型：
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作者：
Flynn KJ;Clark DR;Wheeler G
珊瑚虫是一种神秘的浮游生物，它们产生碳酸钙球石，随着地质时间的推移，这种球石将大气中的二氧化碳埋入石灰岩中，改变了大气和地球的地质。然而，球藻对这些生物增殖的作用尚不清楚；建议包括在抗捕食、增强光合作用和防晒方面的作用。在这里，我们测试了这样的假设，即钙化作用稳定了生物体附近海水的pH值，提供了一定程度的酸化来对抗净光合作用期间发生的有害碱化。这种生物工程为生长提供了更稳定的pH环境，并符合不同环境条件下钙化速率变化的经验证据。在这种情况下，模拟表明，无机和有机颗粒C的最佳生产比率(PIC：POCprod)将较低(约为。20%)随着海洋酸化，在未来酸化的海洋中球藻的过量生产，那里的pH缓冲更弱，对钙化细胞构成风险。
Coccolithophorids are enigmatic plankton that produce calcium carbonate coccoliths, which over geological time have buried atmospheric CO2 into limestone, changing both the atmosphere and geology of the Earth. However, the role of coccoliths for the proliferation of these organisms remains unclear; suggestions include roles in anti-predation, enhanced photosynthesis and sun-screening. Here we test the hypothesis that calcification stabilizes the pH of the seawater proximate to the organisms, providing a level of acidification countering the detrimental basification that occurs during net photosynthesis. Such bioengineering provides a more stable pH environment for growth and fits the empirical evidence for changes in rates of calcification under different environmental conditions. Under this scenario, simulations suggest that the optimal production ratio of inorganic to organic particulate C (PIC : POCprod) will be lower (by approx. 20%) with ocean acidification and that overproduction of coccoliths in a future acidified ocean, where pH buffering is weaker, presents a risk to calcifying cells.