Carbon and Nutrient Dynamics and Fluxes over Shelf Systems (CANDYFLOSS)

巨大的大陆块被广袤的浅海(约100米深)所包围，这些浅海被称为“陆架海”。它们是巨大扰动的陆地环境和广阔的公海海洋系统之间的分界线，具有巨大的社会经济意义。它们是人类开发海洋资源的主要区域，包括可再生能源和化石燃料能源、娱乐、贸易和粮食生产。虽然陆架海仅占全球海洋表面积的5%左右，但却提供了全球90%的渔获量，而这些渔获量构成了全球许多人口的重要食物来源。它们还在整个海洋提供的生态系统服务中发挥重要作用，特别是在将碳储存在远离大气层的地方。陆架海的物理和生化过程影响从大气中去除二氧化碳以及随后在深海储存碳。生物生长吸收水中的碳，然后被大气中二氧化碳中的碳所取代。在陆架海，这种增长是由陆地和开阔海洋的营养源支持的，这意味着陆地生物圈和开阔海洋环境在调节陆架海洋气候服务方面发挥了密切作用。海洋也可能是包括一氧化二氮(N2O)在内的其他温室气体的主要来源或汇，浅海大陆架被认为发挥了关键作用。水下大陆架的空间范围差异很大。欧洲西北部大陆架海是最大的大陆架海之一，因此可能在海洋生物地球化学循环中发挥重要作用，并为其他系统提供了一个有用的模型。然而，即使在这个研究相对较好的区域，我们也缺乏对碳和主要营养元素氮、磷和硅循环的主要控制因素的很好了解。因此，也很难预测这些元素的循环以及它们所支持的碳去除可能会如何被正在进行的和未来可能发生的全球变化所改变。我们的建议旨在通过全面研究西北欧洲大陆架海系水柱中主要营养物质和碳的循环来解决这些不确定因素。通过与一系列合作伙伴的密切合作，我们将对整个欧洲西北大陆架进行为期一年的观测计划。我们将测量海水中主要形态碳和营养物质的浓度。结合实际的水传输和测量的大气和海面之间气体(特别是二氧化碳和N2O)的传输，我们将量化陆架海与邻近深海和大气之间的主要营养物质和碳的通量。这将最终确立这一陆架系统在全球碳循环和营养循环中的作用。我们还将进行4次专门的研究巡航，重点了解不同形式的营养物质和碳的生物和化学加工的季节性周期。我们将测量光合作用浮游生物和消费浮游生物将营养物质和碳吸收到其细胞材料中的速度，以及随后这一生物/化学系统的组合活动如何影响主要元素的循环。这将使我们能够了解如何维持搁置系统在全球周期中的作用。这项提案和其他方案工作包所提供的综合工作将使我们能够确定西北部欧洲搁置系统的哪些方面可能会受到当前或未来环境变化的影响。这些知识将为政策制定者和其他利益攸关方提供更好的科学理解和改进的预测工具。

The large continental land masses are surrounded by extensive shallow (ca 100m depth) seas known as the 'shelf seas'. These act as the boundary between the massively perturbed terrestrial environment and the vast open ocean marine system, and have huge socio-economic importance. They are the primary regions of human marine resource exploitation, including both renewable and fossil fuel energy sources, recreation, trade and food production. Although comprising only about 5% of the global ocean surface area, the shelf seas provide 90% of the global fish catches which form an important source of food to much of the global population. They also play an important role in the ecosystem services provided by the oceans as a whole, in particular in storing carbon away from the atmosphere.Physical and biochemical processes in shelf seas influence the removal of CO2 from the atmosphere and the subsequent storage of carbon in the deep ocean. Biological growth draws carbon out of the water, which is then replaced by carbon in CO2 from the atmosphere. In the shelf seas this growth is supported by terrestrial and open ocean sources of nutrients, implying intimate roles for both the terrestrial biosphere and the open ocean environment in regulating shelf sea climate services. The oceans can also be a major source or sink for other greenhouse gases, including nitrous oxide (N2O), with the shallow shelf seas thought to play a key role.The spatial extent of the submerged continental shelves varies greatly. The NW European shelf sea is one of the largest and hence is likely to play a significant role in marine biogeochemical cycling, alongside providing a useful model for other systems However, even in this relatively well studied region, we lack a good understanding of the principal controls on the cycling of carbon and the major nutrient elements, nitrogen, phosphorous and silicon. Consequently it is also difficult to predict how the cycling of these elements and hence the carbon removal they support may be altered by ongoing and potential future global change. Our proposal aims to address these uncertainties through a comprehensive study of the cycling of the major nutrients and carbon throughout the water column over the NW European shelf sea system.Through close collaboration with a range of partners, we will undertake a year-long observation programme of the whole NW European continental shelf. We will measure the seawater concentrations of the major forms of carbon and nutrients. Combining these with physical water transports and measured transfer of gases (specifically CO2 and N2O) between the air and sea surface, we will quantify the major fluxes of nutrients and carbon between the shelf sea and both the adjacent deep ocean and atmosphere. This will definitively establish the role of this shelf system in the global carbon and nutrient cycles. We will also undertake 4 dedicated research cruises focused on understanding the seasonal cycle of biological and chemical processing of the different forms of the nutrients and carbon. We will measure the rates at which both the photosynthetic and consumer plankton incorporate nutrients and carbon into their cellular material, and subsequently how the combined activity of this biological/chemical system influences the cycling of the major elements. This will allow us to understand the ways in which the role of the shelf system in global cycles is maintained.The combined work delivered by both this proposal and the other programme workpackages will allow us to identify aspects of the NW European shelf system which may be susceptible to ongoing or future environmental changes. Such knowledge will provide both enhanced scientific understanding and improved predictive tools for policy makers and other stakeholders.