Shallow Water Marine Sediment Bacterial Community Shifts Along a Natural CO2 Gradient in the Mediterranean Sea Off Vulcano, Italy
Shallow Water Marine Sediment Bacterial Community Shifts Along a Natural CO2 Gradient in the Mediterranean Sea Off Vulcano, Italy
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DOI：
10.1007/s00248-014-0368-7
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发表时间：
2014-05-01
影响因子：
3.6
通讯作者：
Adams, Jonathan M.
中科院分区：
文献类型：
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作者：
Kerfahi, Dorsaf;Hall-Spencer, Jason M.;Adams, Jonathan M.
大气中二氧化碳含量增加对海洋生态系统的影响是一个主要的环境问题，因为碳酸盐饱和层的迅速变浅使世界各地的大片海洋沉积物暴露在腐蚀性沃茨中。自然CO2梯度关闭Vulcano，意大利，揭示了深刻的生态系统变化沿着岩石海岸栖息地的碳酸盐饱和度下降，但还没有调查的沉积栖息地。在这里，我们采样了三个区域的火山砂上部2厘米，环境（中值pCO（2）419 mu atm，最小Omega（arag）3.77），中度CO2富集（中值pCO（2）592 mu atm，最小Omega（arag）2.96）和高度CO2富集（中值pCO（2）1611 mu atm，最小Omega（arag）0.35）。我们测试了这一假设，即海水pCO（2）水平的增加会导致沉积物细菌群落组成的显着变化，最近在研究现场的石生生物膜。在这项研究中，16S rRNA基因V1至V3区域的454焦磷酸测序显示，随着pCO的增加，群落组成发生了变化（2）。大多数优势属的相对丰度不受pCO（2）梯度的影响，尽管存在约5%的属（即Georgenia、Lutibacter、Photobacterium、Acinetobacter和Paenibacillus）存在显著差异，但Shannon多样性在长期酸化（> 100年）的沉积物中最大。总的来说，这支持了这样一种观点，即全球海洋pCO（2）的增加将与沉积物细菌群落组成的变化有关，但这些生物中的大多数是有弹性的。然而，需要进一步的工作来评估这些结果是否适用于其他类型的沿海沉积物，以及我们观察到的细菌类群的相对丰度的变化是否可以显着改变海洋沉积物的生物地球化学功能。
The effects of increasing atmospheric CO2 on ocean ecosystems are a major environmental concern, as rapid shoaling of the carbonate saturation horizon is exposing vast areas of marine sediments to corrosive waters worldwide. Natural CO2 gradients off Vulcano, Italy, have revealed profound ecosystem changes along rocky shore habitats as carbonate saturation levels decrease, but no investigations have yet been made of the sedimentary habitat. Here, we sampled the upper 2 cm of volcanic sand in three zones, ambient (median pCO(2) 419 mu atm, minimum Omega(arag) 3.77), moderately CO2-enriched (median pCO(2) 592 mu atm, minimum Omega(arag) 2.96), and highly CO2-enriched (median pCO(2) 1611 mu atm, minimum Omega(arag) 0.35). We tested the hypothesis that increasing levels of seawater pCO(2) would cause significant shifts in sediment bacterial community composition, as shown recently in epilithic biofilms at the study site. In this study, 454 pyrosequencing of the V1 to V3 region of the 16S rRNA gene revealed a shift in community composition with increasing pCO(2). The relative abundances of most of the dominant genera were unaffected by the pCO(2) gradient, although there were significant differences for some 5 % of the genera present (viz. Georgenia, Lutibacter, Photobacterium, Acinetobacter, and Paenibacillus), and Shannon Diversity was greatest in sediments subject to long-term acidification (> 100 years). Overall, this supports the view that globally increased ocean pCO(2) will be associated with changes in sediment bacterial community composition but that most of these organisms are resilient. However, further work is required to assess whether these results apply to other types of coastal sediments and whether the changes in relative abundance of bacterial taxa that we observed can significantly alter the biogeochemical functions of marine sediments.