Morphometry of the diatom Fragilariopsis kerguelensis from Southern Ocean sediment: High-throughput measurements show second morphotype occurring during glacials
Morphometry of the diatom Fragilariopsis kerguelensis from Southern Ocean sediment: High-throughput measurements show second morphotype occurring during glacials
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DOI：
10.1016/j.marmicro.2018.07.002
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发表时间：
2018-09-01
影响因子：
1.9
通讯作者：
Beszteri, Bank
中科院分区：
文献类型：
--
作者：
Kloster, Michael;Kauer, Gerhard;Beszteri, Bank
Fragilariopsis kerguelensis是南大洋沉积物中最丰富的硅藻之一。其形态特征被提议作为代用指标，其依据是与铁的可得性、海面温度和冰川/间冰期条件等的联系。我们研究了F. kerguelensis阀在一个良好的研究沉积物芯记录，重点是冰川和间冰期之间的过渡时期。通过应用高通量硅藻成像和形态测定工作流程，我们发现了两种明显不同的形态类型，它们通过它们的矩形来区分。其中一个优先发生在冰川样品中，而另一个始终存在。这表明，它们的相对丰度取决于环境条件，从而指出的可能性，古代理的基础上F。kerguelensis瓣膜形态测量特征将来可能受益于区分这两种形态型。作为这一想法的初步探索，我们表明，这两种形态的丰度比与古温度已重建使用独立的数据从同一个核心。只有通过图像分析才能精确测量硅藻阀的轮廓和面积，突出了这种方法用于硅藻分析的潜力。
Fragilariopsis kerguelensis is one of the most abundant diatoms in the sediments of the Southern Ocean. Its morphometric features have been proposed as proxies, based on links with, for example, iron availability, sea surface temperature and glacial/interglacial conditions. We investigated morphometric changes in F. kerguelensis valves in a well-studied sediment core record, focusing on transition periods between glacials and interglacials. By applying a high-throughput diatom imaging and morphometry workflow, we found two clearly distinct morphotypes which were differentiated by their rectangularity. One of them occurred preferentially in glacial samples, whilst the other persisted throughout. This indicates that their relative abundances depend on environmental conditions and thereby points to the possibility that paleo-proxies based on F. kerguelensis valve morphometric features might in the future benefit from differentiating these two morphotypes. As an initial exploration of this idea, we show that the abundance ratio of both morphotypes correlates well with paleotemperatures which had been reconstructed using independent data from the same core. Distinguishing between the two morphotypes only became possible by image analysis for precisely measuring diatom valve outlines and area, highlighting the potential of such methods for diatom analyses.