The zinc isotopic composition of siliceous marine sponges: investigating nature's sediment traps
The zinc isotopic composition of siliceous marine sponges: investigating nature's sediment traps
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DOI：
10.1016/j.chemgeo.2013.06.025
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发表时间：
2013-09
期刊：
影响因子：
3.9
通讯作者：
K. Hendry;M. B. Andersen
中科院分区：
文献类型：
--
作者：
K. Hendry;M. B. Andersen
海洋生物蛋白石的锌 (Zn) 含量和同位素组成有可能提供有关养分可用性、利用和颗粒有机物从表层到深水的输出的信息。在这里，我们报告了在南大洋收集的深海海绵骨骼元素（骨针）的锌同位素组成的首次测量。我们的结果强调了两个主要的硅质海绵进化枝（六线海绵和去海绵）之间不同的锌吸收和同位素分馏行为，这很可能与海绵进食策略有关。六线类针状体的锌同位素组成不会在海水中发生分馏，这很可能是由于锌通过海绵的开放内部结构进行运输。相比之下，海绵针表现出与蛋白石锌浓度相关的各种锌同位素组成，很可能反映了它们赖以生存的有机物颗粒中可变的锌同位素组成以及内部分馏过程。
The zinc (Zn) content and isotopic composition of marine biogenic opal have the potential to yield information about the nutrient availability, utilization and export of particulate organic matter from surface to deep waters. Here, we report the first measurements of the Zn isotopic composition of deep-sea marine sponge skeletal elements – spicules – collected in the Southern Ocean. Our results highlight different Zn uptake and isotopic fractionation behavior between the two major siliceous sponge clades (hexactinellids and demosponges), which is most likely linked to sponge feeding strategy. Hexactinellid spicule Zn isotopic compositions are not fractionated with respect to seawater, most likely due to Zn transport via the open internal structure of the sponges. In contrast, demosponge spicules exhibit a wide range of Zn isotopic compositions that are related to the opal Zn concentration, most likely reflecting variable Zn isotope compositions in the organic matter particles on which they feed, and internal fractionation processes.