Phytoplankton production and taxon-specific growth rates in the Costa Rica Dome.
Phytoplankton production and taxon-specific growth rates in the Costa Rica Dome.
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哥斯达黎加穹顶的浮游植物产量和分类单元特定增长率。
DOI：
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发表时间：
2016
影响因子：
2.1
通讯作者：
A. Pasulka
中科院分区：
文献类型：
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作者：
K. Selph;M. Landry;Andrew G. Taylor;A. Gutiérrez‐Rodríguez;M. Stukel;John J. Wokuluk;A. Pasulka
在2010年夏季，我们调查了东热带太平洋19个站点的浮游植物产量和生长率，那里的风和强烈的对流形成了哥斯达黎加穹顶(CRD)，这是一种开放的海洋上升流特征。从8个深度的原位培养样品中估计初级生产量(14C-掺入)和群体特定生长率和净生长率(两处理海水稀释法)。我们的巡航恰逢轻微的厄尔尼诺现象，在CRD只观察到微弱的上升流。然而，浮游植物丰度最高的是圆顶中心附近。然而，混合层增长率在穹顶中心最低(∼0.5~0.9d-1)，但在穹顶边缘(∼0.9~1.0d-1)和邻近沿海水域(0.9-1.3d-1)较高。我们发现，在估计增长率的独立方法之间存在很好的一致性。原氯球菌和聚球藻的混合层增长率在很大程度上被死亡率所平衡，而真核浮游植物呈现正的净增长(∼0.5d-0.6d-1)，即可支持更大的(中游动物)消费者生物量的增长。这是该区域第一次针对特定群体的浮游植物速率估计，它们表明综合初级生产力很高，平均超过1g Cm-2day-1，即使在上升流减少的时期也是如此。
During summer 2010, we investigated phytoplankton production and growth rates at 19 stations in the eastern tropical Pacific, where winds and strong opposing currents generate the Costa Rica Dome (CRD), an open-ocean upwelling feature. Primary production (14C-incorporation) and group-specific growth and net growth rates (two-treatment seawater dilution method) were estimated from samples incubated in situ at eight depths. Our cruise coincided with a mild El Niño event, and only weak upwelling was observed in the CRD. Nevertheless, the highest phytoplankton abundances were found near the dome center. However, mixed-layer growth rates were lowest in the dome center (∼0.5-0.9 day-1), but higher on the edge of the dome (∼0.9-1.0 day-1) and in adjacent coastal waters (0.9-1.3 day-1). We found good agreement between independent methods to estimate growth rates. Mixed-layer growth rates of Prochlorococcus and Synechococcus were largely balanced by mortality, whereas eukaryotic phytoplankton showed positive net growth (∼0.5-0.6 day-1), that is, growth available to support larger (mesozooplankton) consumer biomass. These are the first group-specific phytoplankton rate estimates in this region, and they demonstrate that integrated primary production is high, exceeding 1 g C m-2 day-1 on average, even during a period of reduced upwelling.