Mechanistic understanding of the role of diatoms in the success of the Arctic Calanus complex and implications for a warmer Arctic

对硅藻在北极卡拉努斯复合体成功中的作用的机制理解以及对北极变暖的影响

基本信息

批准号：
NE/P006353/1
负责人：
Daniel Mayor
金额：
$ 55.96万
依托单位：
NATIONAL OCEANOGRAPHY CENTRE
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FP006353%2F1
关键词：
Mechanistic understanding role diatoms success

项目摘要

Copepod species of the genus Calanus (Calanus hereafter) are rice grain-sized crustaceans, distant relatives of crabs and lobsters, that occur throughout the Arctic Ocean consuming enormous quantities of microscopic algae (phytoplankton). These tiny animals represent the primary food source for many Arctic fish, seabirds and whales. During early spring they gorge on extensive seasonal blooms of diatoms, fat-rich phytoplankton that proliferate both beneath the sea ice and in the open ocean. This allows Calanus to rapidly obtain sufficient fat to survive during the many months of food scarcity during the Arctic winter. Diatoms also produce one of the main marine omega-3 polyunsaturated fatty acids that Calanus require to successfully survive and reproduce in the frozen Arctic waters. Calanus seasonally migrate into deeper waters to save energy and reduce their losses to predation in an overwintering process called diapause that is fuelled entirely by carbon-rich fat (lipids). This vertical 'lipid pump' transfers vast quantities of carbon into the ocean's interior and ultimately represents the draw-down of atmospheric carbon dioxide (CO2), an important process within the global carbon cycle. Continued global warming throughout the 21st century is expected to exert a strong influence on the timing, magnitude and spatial distribution of diatom productivity in the Arctic Ocean. Little is known about how Calanus will respond to these changes, making it difficult to understand how the wider Arctic ecosystem and its biogeochemistry will be affected by climate change. The overarching goal of this proposal is to develop a predictive understanding of how Calanus in the Arctic will be affected by future climate change. We will achieve this goal through five main areas of research:We will synthesise past datasets of Calanus in the Arctic alongside satellite-derived data on primary production. This undertaking will examine whether smaller, more temperate species have been increasingly colonising of Arctic. Furthermore, it will consider how the timing of life-cycle events may have changed over past decades and between different Arctic regions. The resulting data will be used to validate modelling efforts.We will conduct field based experiments to examine how climate-driven changes in the quantity and omega-3 content of phytoplankton will affect crucial features of the Calanus life-cycle, including reproduction and lipid storage for diapause. Cutting-edge techniques will investigate how and why Calanus use stored fats to reproduce in the absence of food. The new understanding gained will be used to produce numerical models of Calanus' life cycle for future forecasting.The research programme will develop life-cycle models of Calanus and simulate present day distribution patterns, the timing of life-cycle events, and the quantities of stored lipid (body condition), over large areas of the Arctic. These projections will be compared to historical data.We will investigate how the omega-3 fatty acid content of Calanus is affected by the food environment and in turn dictates patterns of their diapause- and reproductive success. Reproductive strategies differ between the different species of Calanus and this approach provides a powerful means by which to predict how each species will be impacted, allowing us to identify the winners and losers under various scenarios of future environmental changes. The project synthesis will draw upon previous all elements of the proposal to generate new numerical models of Calanus and how the food environment influences their reproductive strategy and hence capacity for survival in a changing Arctic Ocean. This will allow us to explore how the productivity and biogeochemistry of the Arctic Ocean will change in the future. These models will be interfaced with the UK's Earth System Model that directly feeds into international efforts to understand global feedbacks to climate change.

Copepod氏菌（Calanus）属（以下文章）是稻米大小的甲壳类动物，是螃蟹和龙虾的遥远亲属，它们发生在整个北极海洋中，消耗了大量的微量藻类（Phytoplankton）。这些小动物代表了许多北极鱼，海鸟和鲸鱼的主要食物来源。在早春期间，他们在大量的季节性花朵上涂抹硅藻，肥胖的浮游植物泛滥，在海冰下方和开阔的海洋下都散发出来。这使卡拉努斯能够在北极冬季迅速获得足够的脂肪在食物稀缺的许多月中生存。硅藻还产生了卡拉努斯（Calanus）成功生存和繁殖的主要海洋omega-3多不饱和脂肪酸之一。卡拉努斯（Calanus）季节性地迁移到更深的水域中，以节省能源并将其损失减少到捕食的越冬过程中，称为糖尿病，这完全由富含碳的脂肪（脂质）助长。这种垂直的“脂质泵”将大量碳转移到海洋的内部，最终代表了大气二氧化碳（CO2）的缩减，这是全球碳循环中的重要过程。预计整个21世纪的全球变暖将对北极海中硅藻生产力的时机，幅度和空间分布产生强大的影响。关于卡拉努斯将如何应对这些变化，很难理解更广泛的北极生态系统及其生物地球化学将受到气候变化的影响。该提案的总体目标是对北极中的卡拉努斯如何受到未来气候变化的影响进行预测理解。我们将通过研究的五个主要领域实现这一目标：我们将在北极中综合北极的Calanus的数据集与卫星衍生的主要生产数据一起。这项承诺将检查较小，更温带的物种是否越来越多地殖民北极。此外，它将考虑过去几十年以及不同北极地区之间生命周期事件的时机如何发生变化。最终的数据将用于验证建模工作。我们将进行基于现场的实验，以检查浮游植物的数量和omega-3含量的变化如何影响calanus生命周期的关键特征，包括生殖和脂质存储为滞育。尖端的技术将研究卡拉努斯如何以及为什么在没有食物的情况下使用储存的脂肪繁殖。获得的新理解将用于生成Calanus生命周期的数值模型，以供未来预测。研究计划将开发calanus的生命周期模型，并模拟当今的分布模式，生命周期事件的时间和数量储存的脂质（身体状况），在北极的大面积上。这些预测将与历史数据进行比较。我们将研究calanus的omega-3脂肪酸含量如何受食物环境的影响，进而决定其抑郁和生殖成功的模式。生殖策略之间的不同种类的calanus和这种方法提供了一种强大的手段，可以通过预测每个物种的影响，使我们能够在未来环境变化的各种情况下确定赢家和输家。该项目的综合将借鉴提案的以前所有要素，以产生新的卡拉努斯数字模型，以及食品环境如何影响其生殖策略，从而在不断变化的北极海洋中生存能力。这将使我们能够探讨北极海洋的生产力和生物地球化学将来如何改变。这些模型将与英国的地球系统模型相连，该模型直接融入了国际努力，以了解全球对气候变化的反馈。