Where they can't breathe Climate warming is causing the expansion of marine oxygen-deficient zones, which are regions in which dissolved oxygen concentrations are so low that many marine animals cannot survive. This phenomenon also might affect the global cycles of carbon, sulfur, nitrogen, and trace metals in the oceans. Raven et al. show how ocean anoxia affects microbial sulfur processing in sinking marine particles. They observed cryptic microbial sulfate reduction, which forms organic sulfur that is resistant to acid hydrolysis, a process that could enhance carbon preservation in sediments underlying oxygen-deficient water columns. This may help explain some of the more extreme episodes of organic carbon preservation associated with marine anoxia in Earth's history. Science, this issue p. 178 Cryptic sulfur cycling may enhance organic carbon preservation in sediments below marine oxygen–deficient zones. Climate change is driving an expansion of marine oxygen-deficient zones, which may alter the global cycles of carbon, sulfur, nitrogen, and trace metals. Currently, however, we lack a full mechanistic understanding of how oxygen deficiency affects organic carbon cycling and burial. Here, we show that cryptic microbial sulfate reduction occurs in sinking particles from the eastern tropical North Pacific oxygen-deficient zone and that some microbially produced sulfide reacts rapidly to form organic sulfur that is resistant to acid hydrolysis. Particle-hosted sulfurization could enhance carbon preservation in sediments underlying oxygen-deficient water columns and serve as a stabilizing feedback between expanding anoxic zones and atmospheric carbon dioxide. A similar mechanism may help explain more-extreme instances of organic carbon preservation associated with marine anoxia in Earth history.

中文翻译：

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下沉海洋颗粒中的微生物硫酸盐还原和有机硫的形成

他们无法呼吸的地方 气候变暖导致海洋缺氧区扩大，这些地区的溶解氧浓度非常低，许多海洋动物无法生存。这种现象也可能影响海洋中碳、硫、氮和微量金属的全球循环。乌鸦等。展示海洋缺氧如何影响下沉海洋颗粒中的微生物硫处理。他们观察到神秘的微生物硫酸盐还原，它形成了耐酸水解的有机硫，这一过程可以增强缺氧水柱下沉积物中的碳保存。这可能有助于解释地球历史上与海洋缺氧相关的一些更极端的有机碳保存事件。科学，这个问题 p。178 隐性硫循环可能会增强海洋缺氧区以下沉积物中有机碳的保存。气候变化正在推动海洋缺氧区的扩张，这可能会改变碳、硫、氮和微量金属的全球循环。然而，目前我们对缺氧如何影响有机碳循环和埋藏缺乏完整的机制理解。在这里，我们表明神秘的微生物硫酸盐还原发生在来自东热带北太平洋缺氧区的下沉颗粒中，并且一些微生物产生的硫化物会迅速反应形成抗酸水解的有机硫。颗粒承载的硫化可以增强缺氧水柱下方沉积物中的碳保存，并作为扩大的缺氧区和大气二氧化碳之间的稳定反馈。类似的机制可能有助于解释地球历史上与海洋缺氧相关的更极端的有机碳保存情况。