Biofilm-like properties of the sea surface and predicted effects on air-sea CO2 exchange
Biofilm-like properties of the sea surface and predicted effects on air-sea CO2 exchange
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DOI：
10.1016/j.pocean.2016.03.002
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发表时间：
2016-05
影响因子：
4.1
通讯作者：
O. Wurl;C. Stolle;Chu Văn Thuộc;X. Mari
中科院分区：
文献类型：
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作者：
O. Wurl;C. Stolle;Chu Văn Thuộc;X. Mari
由于海表控制着海洋与大气之间的各种相互作用，它对海洋地球化学和气候调节具有深远的作用。海面是与气候有关的气体、热量和粒子交换的门户。因此，为了确定海洋和大气如何在全球范围内相互作用并对环境变化作出反应，必须对海面进行定性和了解。水柱的最高部分被定义为海面微层，并经历强烈的空间和时间动态，主要是由于气象强迫。海面上的波浪阻尼区是由表面活性有机物质的积累造成的，被定义为浮油。天然浮油经常被观察到，但其地球化学性质知之甚少。在本研究中，我们在北太平洋、南中国海和波罗的海的多个站点发现，与底层散装水相比，浮油中的透明外聚合物颗粒（TEP）（任何生物膜的基础）高达40倍。我们发现一个显着较低的富集TEP（高达6）在非光滑的海面相比，其底层散装水。此外，浮油的特点是大量的微生物生物量，另一个共同的特点与传统的生物膜在固体表面。与非光滑样品相比（平均两两相似性为70%），浮油中细菌群落组成逐渐增加（平均.成对相似性为45%），与大量水群落不同，表明TEP-基质为其居民创造了特定的环境。因此，我们得出结论，浮油可以具有生物膜样的特性，颗粒和微生物的过度积累。我们还评估了潜在的分布和频率的滑形成在沿海和海洋区域，以及它们对海气CO2交换的影响，根据文献数据。我们估计，浮油可以减少CO2通量高达15%，因此，在调节海气相互作用中发挥重要的本地和区域作用。
Because the sea surface controls various interactions between the ocean and the atmosphere, it has a profound function for marine biogeochemistry and climate regulation. The sea surface is the gateway for the exchange of climate-relevant gases, heat and particles. Thus, in order to determine how the ocean and the atmosphere interact and respond to environmental changes on a global scale, the characterization and understanding of the sea surface are essential. The uppermost part of the water column is defined as the sea-surface microlayer and experiences strong spatial and temporal dynamics, mainly due to meteorological forcing. Wave-damped areas at the sea surface are caused by the accumulation of surface-active organic material and are defined as slicks. Natural slicks are observed frequently but their biogeochemical properties are poorly understood. In the present study, we found up to 40 times more transparent exopolymer particles (TEP), the foundation of any biofilm, in slicks compared to the underlying bulk water at multiple stations in the North Pacific, South China Sea, and Baltic Sea. We found a significant lower enrichment of TEP (up to 6) in non-slick sea surfaces compared to its underlying bulk water. Moreover, slicks were characterized by a large microbial biomass, another shared feature with conventional biofilms on solid surfaces. Compared to non-slick samples (avg. pairwise similarity of 70%), the community composition of bacteria in slicks was increasingly (avg. pairwise similarity of 45%) different from bulk water communities, indicating that the TEP-matrix creates specific environments for its inhabitants. We, therefore, conclude that slicks can feature biofilm-like properties with the excessive accumulation of particles and microbes. We also assessed the potential distribution and frequency of slick-formation in coastal and oceanic regions, and their effect on air–sea CO2exchange based on literature data. We estimate that slicks can reduce CO2fluxes by up to 15%, and, therefore, play important local and regional roles in regulating air–sea interactions.