Phaeodaria: An Important Carrier of Particulate Organic Carbon in the Mesopelagic Twilight Zone of the North Pacific Ocean
Phaeodaria: An Important Carrier of Particulate Organic Carbon in the Mesopelagic Twilight Zone of the North Pacific Ocean
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DOI：
10.1029/2019gb006258
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发表时间：
2019-08-01
影响因子：
5.2
通讯作者：
Fujiki, Tetsuichi
中科院分区：
文献类型：
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作者：
Ikenoue, Takahito;Kimoto, Katsunori;Fujiki, Tetsuichi
Phaeodaria，其中包括一组大型，单细胞真核浮游动物，在过去的海洋生物学研究中，在很大程度上被忽视，因为Phaeodaria和它们脆弱的骨骼容易崩溃。因此，标本的收集和定量是困难的，并没有彻底研究phaeodarian丰度的季节性变化。只有少数几个代表性的物种的生源要素的下沉phaeodarians的运输进行了估计。在估算沉降颗粒通量时，尺寸大于1毫米的沉降颗粒和游泳者传统上被排除在外。本研究的重点是2014年6月至2015年7月在北太平洋西部收集的>1 mm沉降颗粒中的大量phaeodarians。通过显微镜检查和化学分析的仔细分类表明，在所有沉降颗粒中，浮游生物占有机碳的10%左右，在>1 mm的沉降颗粒中，浮游生物平均占有机碳的33%。中层微暗区150- 1 000米深处大量存在的暗色颗粒表明，富含有机碳的暗色颗粒的压舱作用，可以有效地将从真光层下沉的颗粒聚集体和粪粒输出到深海。
Phaeodaria, which comprise one group of large, single-celled eukaryotic zooplankton, have been largely ignored by past marine biological studies because Phaeodaria and their delicate skeletons are liable to collapse. As a result, collection and quantification of specimens are difficult, and seasonal changes of phaeodarian abundance have not been thoroughly studied. The transport of biogenic elements by sinking phaeodarians has been estimated for only a few representative species. Sinking particles >1 mm in size and swimmers have traditionally been excluded when estimating sinking particle fluxes. The focus of this study is the large number of phaeodarians among the >1-mm sinking particles collected in the western North Pacific from June 2014 to July 2015. Careful sorting by microscopic examination and chemical analyses revealed that phaeodarians accounted for up to about 10% of the organic carbon in all sinking particles and accounted for a mean of 33% of the organic carbon in the >1-mm sinking particles. The high-standing stocks of phaeodarians at depths of 150-1,000 m in the mesopelagic twilight zone suggested that particles sinking from the euphotic zone as aggregates and fecal pellets can be efficiently exported to the deep sea by the ballasting effect of large phaeodarian particles rich in organic carbon.