Deep-sea ecosystem functioning in a changing climate: consequences of changing sea-ice cover for Arctic benthic ecosystems

深海生态系统在气候变化中发挥作用：海冰覆盖变化对北极底栖生态系统的影响

• 批准号: NE/J023094/1
• 负责人: Ursula Witte
• 金额: $ 51.23万
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FJ023094%2F1
• 关键词: Deep; sea; ecosystem; functioning; changing

Deep-sea sediments form a major reservoir in the global carbon (C) cycle and C burial in these sediments constitutes a major process that sequesters C on geological time scales. Organic matter sinking from surface waters is the main food source for deep-sea organisms, and their feeding and foraging activities control whether this organic C is recycled into the water column or buried in sediments ('carbon sequestration'). Food supply to the deep-sea benthos is reliant on phytoplankton growth in the euphotic zone, and changes in community composition, export flux or timing of bloom events will directly affect the supply to and turnover of POC at the seafloor and, subsequently, C sequestration.However, due to the remoteness of the deep-sea floor, our knowledge of the interplay between organic matter characteristics, benthic biodiversity and the early diagenesis of POC in the deep sea is very limited, and we can therefore neither reliably assess nor predict the consequences of climate change for this important ecosystem service. The detailed study of benthic C cycling in areas of strong natural fluctuations in POC flux characteristics, and/or pronounced climate-induced change in the pelagic environment, seems a promising way to gain urgently needed information on the potential impact of climate change on the cycling or burial of C in deep-sea sediments, while at the same time improving our understanding of the interplay between POM characteristics and benthic communities, and its function in the early diagenesis of POM.Sea ice is a unique feature of polar marine ecosystems and the fact that small temperature differences can have large effects on the extent and thickness of this sea ice makes polar marine ecosystems particularly sensitive to climate change. Indeed, major ecosystem shifts related to retreating sea ice have been reported from both the Arctic and Antarctic. Ice algae account for up to 25 % of the primary production (PP) in ice covered areas on the deep Arctic shelf, and even more in the Arctic Basin, and thus are likely to form an integral part of the diet of deep-sea organisms. Moreover, ice algal blooms differ considerably from phytoplankton in terms of timing and distribution, thus providing higher organisms with food when and where other food is scarce. Ice algae also contain very high concentrations of so-called "micronutrients", essential substances that many marine organisms can not synthesize themselves. The retreat of sea ice and subsequent loss of ice algae as food source is thus likely to significantly impact on deep-sea food webs and ecosystems. However, despite much speculation, very little information is available on the importance of ice algae as food for benthic organisms.We therefore propose to investigate the potential consequences of a climate-induced loss of ice algae (and possible shift to phytoplankton) as a food source for Arctic deep-sea food webs via two different approaches: A. Ice algae and phytoplankton differ in their bulk Carbon isotope signatures, as well as in the Carbon isotope signatures of certain essential fatty acids. We will thus use this difference in isotopic signature to trace the uptake of ice algal and phytoplankton biomass by benthic fauna. B. A series of in situ tracer experiments: we will label both ice algae and planktic algae with a tracer, add them to sediment cores obtained from the seafloor (so-called 'mesocosms'), and subsequently follow whether and how they are metabolized by the deep-sea organisms. This work will be carried out in the Canadian Arctic in collaboration with Professor Philippe Archabault from the University of Quebec, during field campaigns in the Gulf of St. Lawrence and the Beaufort Sea.

深海沉积物是全球碳(C)循环的主要储存库，这些沉积物中的碳埋藏是在地质时间尺度上封存碳的主要过程。从地表水下沉的有机物是深海生物的主要食物来源，它们的摄食和觅食活动控制着这些有机碳是被循环进入水柱还是被埋在沉积物中（“碳封存”）。深海底栖生物的食物供应依赖于光带浮游植物的生长，群落组成、输出通量或水华事件时间的变化将直接影响海底POC的供应和周转，进而影响C的封存。然而，由于深海的偏远，我们对深海有机质特征、底栖生物多样性和POC早期成岩作用之间的相互作用的了解非常有限，因此我们既不能可靠地评估也不能预测气候变化对这一重要生态系统服务的影响。底栖生物C循环的详细研究领域的强劲自然波动POC通量特征,和/或明显的气候导致的变化在深海环境中,似乎是一个有前途的方法来获得急需的信息的潜在影响气候变化对C的自行车或埋葬在深海沉积物,同时提高我们理解POM特点和底栖生物群体之间的相互作用,及其在POM的早期成岩作用函数。海冰是极地海洋生态系统的一个独特特征，微小的温差会对海冰的范围和厚度产生巨大影响，这一事实使极地海洋生态系统对气候变化特别敏感。事实上，北极和南极都报道了与海冰消退有关的主要生态系统变化。冰藻占北极深陆架冰覆盖地区初级产量（PP）的25%，在北极盆地甚至更多，因此可能形成深海生物饮食的一个组成部分。此外，冰藻华在时间和分布方面与浮游植物有很大的不同，因此在其他食物稀缺的时候和地方为高等生物提供食物。冰藻还含有高浓度的所谓“微量营养素”，这是许多海洋生物不能自己合成的必需物质。因此，海冰的退缩和作为食物来源的冰藻的丧失可能会对深海食物网和生态系统产生重大影响。然而，尽管有很多猜测，关于冰藻作为底栖生物食物的重要性的信息却很少。因此，我们建议通过两种不同的方法来研究气候引起的冰藻（以及可能向浮游植物转移）作为北极深海食物网食物来源的潜在后果：a .冰藻和浮游植物在体积碳同位素特征以及某些必需脂肪酸的碳同位素特征上存在差异。因此，我们将利用这种同位素特征的差异来追踪底栖动物对冰藻和浮游植物生物量的吸收。B.一系列原位示踪实验：我们将用示踪剂标记冰藻和浮游藻类，将它们添加到从海底获得的沉积物岩心中（所谓的“中生态”），随后跟踪它们是否以及如何被深海生物代谢。这项工作将在加拿大北极地区与魁北克大学的Philippe Archabault教授合作，在圣劳伦斯湾和波弗特海的实地活动期间进行。

项目成果

The influence of depth and season on the benthic communities of a Macrocystis pyrifera forest in the Falkland Islands

• DOI: 10.1007/s00300-020-02662-x
• 发表时间: 2020-04-09
• 期刊: POLAR BIOLOGY
• 影响因子: 1.7
• 作者: Beaton, Emma C.;Kupper, Frithjof C.;Brickle, Paul
• 通讯作者: Brickle, Paul

Iodine and fluorine concentrations in seaweeds of the Arabian Gulf identified by morphology and DNA barcodes

通过形态和 DNA 条形码识别阿拉伯湾海藻中的碘和氟浓度

• 发表时间: 2020
• 作者: []

The influence of marine algae on iodine speciation in the coastal ocean

海藻对近海碘形态的影响

• DOI: 10.4490/algae.2020.35.5.25
• 发表时间: 2020
• 期刊: ALGAE
• 影响因子: 3.2
• 作者: Carrano, Mary W.;Yarimizu, Kyoko;Gonzales, Jennifer L.;Cruz-López, Ricardo;Edwards, Matthew S.;Tymon, Teresa M.;Küpper, Frithjof C.;Carrano, Carl J.
• 通讯作者: Carrano, Carl J.

Organic matter remineralization in marine sediments: A Pan-Arctic synthesis

• DOI: 10.1002/2016gb005378
• 发表时间: 2017-01-01
• 期刊: GLOBAL BIOGEOCHEMICAL CYCLES
• 影响因子: 5.2
• 作者: Bourgeois, Solveig;Archambault, Philippe;Witte, Ursula
• 通讯作者: Witte, Ursula

DNA barcoding of marine algae from Malta: new records from the central Mediterranean

• DOI: 10.37427/botcro-2021-020
• 发表时间: 2021-10-01
• 期刊: ACTA BOTANICA CROATICA
• 影响因子: 1.3
• 作者: Bartolo, Angela G.;Zammit, Gabrielle;Kupper, Frithjof C.
• 通讯作者: Kupper, Frithjof C.