In Situ Incubation and Filtration System for the Pelagic Ocean (InSIncFS)

远洋原位孵化和过滤系统 (InSIncFS)

• 批准号: NE/X005941/1
• 负责人: Phyllis Lam
• 金额: $ 95.47万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX005941%2F1
• 关键词: Situ; Incubation; Filtration; System; Pelagic

The Ocean is a key climate regulator: Has it not been its 'biological carbon pump' (BCP), atmospheric CO2 would have been at least twice as high as it is today. BCP operates with CO2 firstly absorbed and fixed into organic carbon in the surface ocean by photosynthetic phytoplankton, then a fraction of this carbon is transferred into the deep interior of the ocean where it is locked away (sequestered) for centuries. Hence, the efficiency of BCP relies on the productivity of surface phytoplankton, interactions with other microbes and organisms that might hamper the carbon delivery to the deep, and respiration -feeding on the fixed carbon as food and converted back to CO2- in the twilight ocean, the critical buffer zone between the sunlit surface and the deep ocean. Meanwhile, it is also this phytoplankton-derived fixed carbon that feeds the majority of diverse marine life, and forms the basis of many ecosystem services and food security that humans enjoy. Under current, rapid climate change, ocean warming and stratification limits the replenishment of nutrients in the surface ocean, while seawater becomes more acidic and loses oxygen. The latter especially can stimulate production of even stronger greenhouse gases like methane and nitrous oxide. Clearly, accurate understanding of all these biogeochemical processes, mediated mostly by small plankton and microbes, is critical to our ability to project future changes on our planet.How marine biogeochemists and plankton ecologists have been assessing activity of these important processes to date are mostly based on incubation experiments conducted on shipboard: Briefly, samples of water and resident plankton are taken out from ocean depths, brought onto ship-deck and into various bottles, perhaps with additions of indicator compounds for tracing changes (e.g. rare isotopes 13C and 15N) or hypothesised substrates that might simulate activity (e.g. iron). They are placed in a lab incubator at similar temperature as found at in situ depths for a period of time to monitor changes in chemical/biological properties, possibly with screens to mimic light intensity in deeper water. However, atmospheric pressure is typically used in ex-situ incubations, even though the sample may have come from 100's-1000's m depth, so decompression to 1 bar from originally 10's to 100's bar! As one can imagine, the conditions experienced by the plankton/ microbes during such ex-situ incubations can be vastly different from their real habitats, and any activity measurements thus obtained most certainly differ from reality. Moreover, 'omics analyses, especially those of RNA, have recently become very useful in studying active metabolisms and pathways organisms use (e.g. Tara Oceans). However, plankton respond quickly to changes and RNA can be altered within seconds to minutes, so they have most likely changed during the journey between sampled water depths and the collection on ship-deck.Despite these artefacts, shipboard incubations and RNA filtration are widely used - because there is no other practical option. It is unknown how much error and extent of misunderstanding such artefact-laden activity measurements and RNA profiles might have brought, and they are currently used in models.The proposed In Situ Incubation and Filtration System (InSIncFS) for the pelagic ocean will provide, for the first time, a transformative platform for truly in situ activity assessments with integrated sensors, large array of possible parallel hypothesis-driven experiments, and in situ RNA-preservation. It will eliminate the artefacts of ex situ incubations, and correct for the inaccuracies of activities previously determined ex situ. No such system exists in the world. InSIncFS will enable us to truly answer questions on climate change that has not been possible before. It represents world-class innovation and paves the way toward NERC's ambition of Net Zero Oceanographic Capability on autonomous activity sensing.

海洋是一个关键的气候调节器：如果不是它的‘生物碳泵’(BCP)，大气中的二氧化碳至少会是今天的两倍。BCP的运作方式是，二氧化碳首先被光合作用的浮游植物吸收并固定在表层海洋中的有机碳中，然后这些碳的一小部分被转移到海洋深处，在那里被锁定(隔离)数个世纪。因此，BCP的效率取决于表层浮游植物的生产力，与其他微生物和生物体的相互作用，这可能会阻碍碳向深海的输送，以及呼吸-以固定碳为食物并在暮光海洋中转化回CO2-，这是阳光充足的表面和深海之间的关键缓冲区。同时，也正是这种浮游植物衍生的固定碳养活了大多数不同的海洋生物，并构成了人类享有的许多生态系统服务和食品安全的基础。在当前迅速的气候变化下，海洋变暖和层化限制了表层海洋营养物质的补充，而海水变得更加酸性，失去了氧气。后者尤其可以刺激产生更强的温室气体，如甲烷和一氧化二氮。显然，对所有这些主要由小浮游生物和微生物介导的生物地球化学过程的准确理解，对于我们预测地球未来变化的能力至关重要。海洋生物地球化学家和浮游生物生态学家迄今一直在评估这些重要过程的活动，主要是基于船上进行的培养实验：简单地说，从海洋深处提取水和浮游生物样本，带到船甲板上并放入不同的瓶子，可能会添加用于跟踪变化的指示化合物(例如稀有同位素13C和15N)或可能模拟活动的假设底物(例如铁)。它们被放置在实验室孵化器中，温度与在现场深处发现的温度相似，并持续一段时间，以监测化学/生物特性的变化，可能会有屏幕来模拟更深水域的光强度。然而，大气压通常用于异地孵化，即使样品可能来自100‘S-1000’S米深处，所以减压从原来的10‘S到100’S吧！正如人们可以想象的那样，浮游生物/微生物在这种异地孵化过程中所经历的条件可能与它们的真实栖息地有很大的不同，因此获得的任何活动测量结果都肯定与现实不符。此外，组学分析，特别是RNA的组学分析，最近在研究活跃的新陈代谢和生物利用的途径方面变得非常有用(例如，Tara Ocean)。然而，浮游生物对变化的反应很快，RNA可以在几秒钟到几分钟内改变，所以它们很可能在采样水深和在船甲板上收集之间的旅程中发生了变化。尽管存在这些人工制品，但船上培养和RNA过滤被广泛使用-因为没有其他实用的选择。目前尚不清楚这种人工制品带来的活动测量和RNA图谱可能会带来多大的误差和误解的程度，目前它们正被用于模型中。拟议的远洋原位孵化和过滤系统(InSIncFS)将首次提供一个变革性的平台，利用集成的传感器、大量可能的平行假设驱动的实验和原位RNA保存来进行真正的原位活动评估。它将消除异地孵化的伪影，并纠正先前确定的异地孵化活动的不准确性。世界上不存在这样的制度。InSIncFS将使我们能够真正回答有关气候变化的问题，这是以前不可能的。它代表了世界级的创新，并为NERC在自主活动传感方面实现净零海洋能力的雄心铺平了道路。