School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332-0340, USA.
Nat Commun. 2013;4:1981. doi: 10.1038/ncomms2981.
Iron has a key role in controlling biological production in the Southern Ocean, yet the mechanisms regulating iron availability in this and other ocean regions are not completely understood. Here, based on analysis of living phytoplankton in the coastal seas of West Antarctica, we present a new pathway for iron removal from marine systems involving structural incorporation of reduced, organic iron into biogenic silica. Export of iron incorporated into biogenic silica may represent a substantial unaccounted loss of iron from marine systems. For example, in the Ross Sea, burial of iron incorporated into biogenic silica is conservatively estimated as 11 μmol m⁻² per year, which is in the same range as the major bioavailable iron inputs to this region. As a major sink of bioavailable iron, incorporation of iron into biogenic silica may shift microbial population structure towards taxa with relatively lower iron requirements, and may reduce ecosystem productivity and associated carbon sequestration.
铁在控制南大洋的生物生产力方面起着关键作用，但人们对调节这一海洋区域和其他海洋区域铁可利用性的机制还不完全了解。在这里，我们基于对南极洲西部沿海海域的浮游植物的分析，提出了一种新的从海洋系统中去除铁的途径，涉及将还原态有机铁结构纳入生物硅中。结合生物硅的铁的输出可能代表了从海洋系统中大量未被发现的铁的损失。例如，在罗斯海，结合生物硅的铁的埋藏量保守估计为每年 11 μmol m ⁻² ，这与该区域主要的生物可利用铁输入量处于同一范围。作为生物可利用铁的主要汇，将铁纳入生物硅可能会使微生物种群结构向相对较低铁需求的类群转移，并可能降低生态系统生产力和相关的碳固存。
