Compound specific amino acid delta13C patterns in a deep-sea proteinaceous coral: Implications for reconstructing detailed delta 13C records of exported primary production
Compound specific amino acid delta13C patterns in a deep-sea proteinaceous coral: Implications for reconstructing detailed delta 13C records of exported primary production
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深海蛋白质珊瑚中复合特定氨基酸 delta13C 模式：重建出口初级生产的详细 delta13C 记录的意义
DOI：
10.1016/j.marchem.2014.09.008
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发表时间：
2014
期刊：
影响因子：
3
通讯作者：
M. McCarthy
中科院分区：
文献类型：
--
作者：
John T. Schiff;F. Batista;O. Sherwood;T. Guilderson;T. Hill;A. Ravelo;K. McMahon;M. McCarthy
深海蛋白质珊瑚是高分辨率的古档案，其生物地球化学时间序列远远超出了最近的仪器数据。虽然最近的研究已经应用复合特定氨基酸δ 15 N（δ 15 N-AA）测量其有机骨架层来研究全新世氮循环，但氨基酸δ 13 C（δ 13 C-AA）在蛋白质珊瑚中的潜在应用尚未得到研究。本文对深海竹珊瑚（Isidellasp.）从蒙特里峡谷重建出口初级生产超过80年的记录。保存的深海珊瑚必需氨基酸δ 13 C-AA模式（δ 13 C-EAA）与天然和养殖浮游植物的预期模式非常吻合，支持深海珊瑚δ 13 C-EAA值代表出口初级生产来源的不变特征的假设。在过去的世纪中，珊瑚体δ 13 C记录显示出0.5‰的周期性变化，在20世纪60年代初转向较低的δ 13 C值。珊瑚δ 13 C-EAA值的变化与δ 13 C的整体特征密切相关，尽管与δ 13 C-EAA记录相比，δ 13 C整体记录的变化范围和幅度都大大减弱。我们的研究结果表明，蛋白质珊瑚中的δ 13 C-EAA代表了初级生产中δ 13 C的一种新的直接替代物，比散装δ 13 C更敏感和准确。为了验证这一想法，我们使用现有的浮游植物δ 13 C-AA数据来计算大量δ 13 C和δ 13 C-EAA之间的偏移。当应用到我们的数据，输出的有机质的δ 13 C值的重建记录是一致的区域浮游植物动态和预期的营养转移效应，表明显着的AA再合成仅在非必需的AA池。总之，这些结果表明，深海蛋白质珊瑚中的δ 13 C-EAA为研究出口初级生产和生物地球化学的变化提供了一个强大的新的长期，高分辨率的工具。
Deep-sea proteinaceous corals represent high-resolution paleoarchives, extending biogeochemical time series far beyond recent instrumental data. While recent studies have applied compound specific amino acid δ15N (δ15N-AA) measurements of their organic skeletal layers to investigate Holocene nitrogen cycling, potential applications of amino acid δ13C (δ13C-AA) in proteinaceous corals have not yet been examined. Here we developed δ13C-AA analysis in deep-sea bamboo coral (Isidellasp.) from the Monterey Canyon to reconstruct exported primary production over an ~ 80 year record. Preserved deep-sea coral essential amino acid δ13C-AA patterns (δ13C-EAA) closely matched those expected from natural and cultured phytoplankton, supporting the hypothesis that deep-sea coral δ13C-EAA values represent unaltered signatures of exported primary production sources. The coral bulk δ13C record showed cyclic 0.5‰ variations over the last century, with a shift to lower δ13C values in the early 1960s. Variations in coral δ13C-EAA values closely followed bulk δ13C signatures, although both the range and the magnitude of change in the bulk δ13C record were highly attenuated compared to the δ13C-EAA record. Our results indicate that δ13C-EAA in proteinaceous corals represent a new, direct proxy for δ13C in primary production that is more sensitive and accurate than bulk δ13C. To test this idea, we used existing phytoplankton δ13C-AA data to calculate an offset between bulk δ13C and δ13C-EAA. When applied to our data, a reconstructed record of δ13C values for exported organic matter was consistent with regional phytoplankton dynamics and expected trophic transfer effects, suggesting significant AA resynthesis only in the non-essential AA pool. Together, these results indicate that δ13C-EAA in deep-sea proteinaceous corals provide a powerful new long-term, high resolution tool for investigating variations in exported primary production and biogeochemistry.