Remineralization of particulate organic carbon in an ocean oxygen minimum zone.
Remineralization of particulate organic carbon in an ocean oxygen minimum zone.
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DOI：
10.1038/ncomms14847
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发表时间：
2017-03-21
影响因子：
16.6
通讯作者：
Sanders R
中科院分区：
文献类型：
--
作者：
Cavan EL;Trimmer M;Shelley F;Sanders R
生物海洋过程，主要是表面的生产，下沉和有机颗粒的内部矿化，保持大气中的二氧化碳低于如果海洋是非生物的。颗粒化长度尺度（RLS，有机颗粒通量下降63%的垂直距离，受颗粒呼吸，破碎和下沉速率的影响）控制着这种效应的大小，并且在氧气最小区（OMZ）非常高。在这里，我们表明在东热带北太平洋OMZ 70%的POC矿化是由于微生物呼吸，表明高RLS是浮游动物较低的颗粒破碎的结果，可能是由于OMZ沃茨中几乎完全没有浮游动物颗粒相互作用。因此，浮游动物对海洋氧浓度的敏感性可能对大气碳固存产生直接影响。未来有机开放区的扩大可能会增加海洋生物碳储存，并对气候变化产生负面反馈。相对于含氧沃茨，在最低含氧区，有机碳从表层向下转移到深海的情况有所增加。在这里，作者表明，由于低氧，浮游动物与下沉颗粒的相互作用减少，这可能是观察到的高碳转移的主要原因。
Biological oceanic processes, principally the surface production, sinking and interior remineralization of organic particles, keep atmospheric CO2 lower than if the ocean was abiotic. The remineralization length scale (RLS, the vertical distance over which organic particle flux declines by 63%, affected by particle respiration, fragmentation and sinking rates) controls the size of this effect and is anomalously high in oxygen minimum zones (OMZ). Here we show in the Eastern Tropical North Pacific OMZ 70% of POC remineralization is due to microbial respiration, indicating that the high RLS is the result of lower particle fragmentation by zooplankton, likely due to the almost complete absence of zooplankton particle interactions in OMZ waters. Hence, the sensitivity of zooplankton to ocean oxygen concentrations can have direct implications for atmospheric carbon sequestration. Future expansion of OMZs is likely to increase biological ocean carbon storage and act as a negative feedback on climate change. The downward transfer of organic carbon from the surface to the deep ocean is increased in oxygen minimum zones relative to oxic waters. Here, the authors show reduced interactions of zooplankton with sinking particles owing to low oxygen are likely the primary reason for the observed high transfer of carbon.