Potential drivers of sinking particle's size spectra and vertical flux of particulate organic carbon (POC): Turbulence, phytoplankton, and zooplankton
Potential drivers of sinking particle's size spectra and vertical flux of particulate organic carbon (POC): Turbulence, phytoplankton, and zooplankton
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下沉颗粒尺寸谱和颗粒有机碳 (POC) 垂直通量的潜在驱动因素：湍流、浮游植物和浮游动物
DOI：
10.1002/2013jc009754
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发表时间：
2014
影响因子：
--
通讯作者：
S. Basedow
中科院分区：
文献类型：
--
作者：
I. Wiedmann;M. Reigstad;A. Sundfjord;S. Basedow
温带和高纬度陆架海域的浮游植物春季繁殖通常与从泛光带输出聚集体的颗粒有机碳（POC）增加有关。相比之下，开花后的情况通常与主要的POC保留有关，其中小细胞（<10 μm）和强放牧压力占主导地位。本研究旨在研究湍流、浮游植物、水华阶段和浮游动物丰度对下沉颗粒粒径谱和POC通量的影响，以提高对100 m以上下沉通量机制的认识。我们在巴伦支海（一个北极陆架海）沿分层和浮游植物繁盛梯度的四个深度放置了沉淀物捕集器，部分用凝胶罐进行了改造。尽管食草动物的丰度很高（12,000个体m−3），但在深混合、开花后受大西洋影响的水域中，POC输出最高（60 m: 923 mg C m−2 d−1）。粒径谱显示，该通量以等效球直径0.05 ~ 1.00 mm的颗粒（esimage）为主，POC：体积比与桡足类粪便颗粒匹配。大颗粒（0.5 ~ 2.8 mm ESDimage）在分层后期峰华站和极锋分层后期峰华站的通量中占主导地位，但POC：体积比和POC通量较低（60 m: <823 mg C m−2 d−1）。因此，绿化带底部的高POC通量并不一定是由大型浮游植物聚集体驱动的，也可能以高POC含量的粪便颗粒碎片的形式出现在华后情况下。
Phytoplankton spring blooms in temperate and high-latitude shelf seas are commonly associated with an enhanced particulate organic carbon (POC) export of aggregates from the euphotic zone. In contrast, a postbloom situation is usually linked to a predominant POC retention, where small cells (<10 μm) and strong grazing pressure prevail. This study aimed to examine impacts of turbulence, phytoplankton, bloom stage, and zooplankton abundance on the sinking particles' size spectra and POC flux to improve the understanding of the downward flux mechanisms in the upper 100 m. We deployed sediment traps, partly modified with gel jars, at four depths along a stratification and phytoplankton bloom gradient in the Barents Sea, an Arctic shelf sea. The highest POC export (60 m: 923 mg C m−2 d−1) was found in deep-mixed, postbloom Atlantic influenced waters, despite the high grazer abundance (12,000 individuals m−3). Particle size spectra indicated that this flux was dominated by particles of 0.05–1.00 mm equivalent spherical diameter (ESDimage) with a POC:volume ratio matching copepod fecal pellets. Large particles (0.5–2.8 mm ESDimage) dominated the flux at a stratified, late peak bloom station in Arctic Waters and a stratified, late bloom situation at the Polar Front, but with lower POC:volume ratio and POC flux (60 m: <823 mg C m−2 d−1). Accordingly, a high POC flux at the base of the euphotic zone is not necessarily driven by large phytoplankton aggregates, but can also occur during a postbloom situation in form of small fecal pellet fragments with high POC content.