Elevated trace metal content of prokaryotic communities associated with marine oxygen deficient zones
Elevated trace metal content of prokaryotic communities associated with marine oxygen deficient zones
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DOI：
10.1002/lno.10363
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发表时间：
2017-01
影响因子：
4.5
通讯作者：
D. Ohnemus;S. Rauschenberg;G. Cutter;J. Fitzsimmons;R. Sherrell;B. Twining
中科院分区：
文献类型：
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作者：
D. Ohnemus;S. Rauschenberg;G. Cutter;J. Fitzsimmons;R. Sherrell;B. Twining
关于海洋原核生物的微量金属含量知之甚少，部分原因是它们与上层海洋中更丰富的颗粒相共存，如浮游植物和生物碎屑，岩石矿物和自生Mn和Fe羟基氧化物。我们试图从美国GEOTRACES东太平洋带状样带（巡航GP 16）在东热带南太平洋（ETSP），表现出一致的最大值P和其他生物活性的微量金属，和最小值的颗粒Mn，在缺氧区（ODZs）的13个站的颗粒数据中分离这些生物量信号。亚硝酸盐最大值和硝酸盐赤字表明ETSP ODZ内存在浓缩的原核生物量，10个站点ODZ上边界的深层次生荧光最大值也表明存在低光自养群落。在西经99°处观测到臭氧消耗区，距离南美洲海岸超过2300公里，在那里风成岩和侧向/再悬浮沉积物的输入可以忽略不计，这为研究原核金属化学计量提供了一个独特的机会。ODZ颗粒P最大值可以竞争环流混合层生物量浓度，对氧高度敏感，并且超过当地Fe羟基氧化物和酸挥发性硫化物可清除的量。即使在对成岩和铁清除金属进行校正后，ODZ P-最大值通常富含Cd，Co，Cu，Ni，V和Zn，表现出颗粒痕量金属与P的比率超过混合层生物量比率2-9倍。ODZ原核生物群落可能在很大程度上是隐藏的，TM丰富的游泳池参与海洋循环的这些生物活性的微量金属。
Little is known about the trace metal content of marine prokaryotes, in part due to their co‐occurrence with more abundant particulate phases in the upper ocean, such as phytoplankton and biogenic detritus, lithogenic minerals, and authigenic Mn and Fe oxyhydroxides. We attempt to isolate these biomass signals in particulate data from the US GEOTRACES Eastern Pacific Zonal Transect (cruise GP16) in the Eastern Tropical South Pacific (ETSP), which exhibited consistent maxima in P and other bioactive trace metals, and minima in particulate Mn, in the oxygen deficient zones (ODZs) of 13 stations. Nitrite maxima and nitrate deficits indicated the presence of denitrifying prokaryotic biomass within ETSP ODZs, and deep secondary fluorescence maxima at the upper ODZ boundaries of 10 stations also suggested the presence of low‐light, autotrophic communities. ODZs were observed as far west as 99°W, more than 2300 km from the South American coast, where eolian lithogenic and lateral/resuspended sedimentary inputs were negligible, presenting a unique opportunity to examine prokaryotic metal stoichiometries. ODZ particulate P maxima can rival gyre mixed layer biomass concentrations, are highly sensitive to oxygen, and are in excess of amounts scavengable by local Fe oxyhydroxides and acid–volatile sulfides. Even after correction for lithogenic and ferruginous–scavenged metals, ODZ P‐maxima are often enriched in Cd, Co, Cu, Ni, V, and Zn, exhibiting particulate trace metal ratios to P that exceed mixed layer biomass ratios by factors of 2–9. ODZ prokaryotic communities may be largely hidden, TM–rich pools involved in the marine cycles of these bioactive trace metals.