From ice to ocean: Understanding the impacts of melting glaciers on marine biogeochemical cycles

从冰到海洋：了解冰川融化对海洋生物地球化学循环的影响

• 批准号: RGPIN-2020-05975
• 负责人: Bhatia, Maya
• 金额: $ 2.19万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750893
• 关键词: ice; ocean; Understanding; impacts; melting

Climate change is the defining challenge of our times, fundamentally reorganizing our planet's ecosystems and the human societies they support. Nowhere is this more evident than in Canada's Arctic, where melting glaciers define the landscape. While the contributions of these shrinking ice masses to sea level rise are undisputed, their role in broader biogeochemical cycling is just beginning to be revealed. When glaciers melt, they contribute large quantities of water, ice, sediments, and dissolved chemicals to the ocean. Recent work around Greenland and Antarctica shows that glacially-associated nutrients and carbon have the potential to stimulate production at the base of marine food webs with associated impacts up the food chain (e.g., enhanced local fish harvests) and on the broader carbon cycle via a more active marine biological pump. Yet, knowledge gaps remain about what life-essential elements are exported from glacial systems, what happens to this discharge in the ocean, and what the impacts are on marine microbial communities. Nowhere are these gaps in knowledge more prominent than in the Canadian Arctic Archipelago (CAA) - a region where the role of glacial meltwater in marine biogeochemical cycles is largely unexplored - despite the fact that the CAA is a hotspot for glacial retreat and meltwater runoff to the ocean. Over the next 5 years, my group and I will work to quantify contemporary export of nutrients and carbon from glacial systems, and the associated impact of this export on marine processes and ecosystems. Specifically we will ask: 1) What is the source of biogeochemical constituents (nutrients, carbon) leaving the ice system? 2)What is the fate of glacial meltwater and its associated constituents in the coastal ocean? and 3) How does glacial meltwater impact marine microbial community production, structure, and function? To answer these questions we will conduct novel ice-to-ocean studies, combining field measurements of chemical species with molecular biological assays and laboratory experiments. This approach will address the impact of meltwater interactions close to the glacier termini and at broader regional scales, and target unanswered mechanistic questions. My program will be achieved by HQP using interdisciplinary techniques, bridging oceanography, geochemistry and microbial ecology. Together we will do this work in Jones Sound in the CAA, a region surrounded by glaciers and home to Inuit hamlet of Grise Fiord. The termini of tidewater glaciers here are highly productive waters, serving as hunting grounds for the hamlet. Understanding the drivers of marine production at the base of the food web, and the susceptibility of these drivers to climate change, is important to the long-term health of this northern community, and to coastal Arctic ocean functioning. Collectively, this research is a critical step towards revealing the role of melting glaciers on the marine carbon cycle in the past, present, and future.

气候变化是我们时代的决定性挑战，从根本上重组了我们的星球生态系统和所支持的人类社会。没有什么比在加拿大北极融化冰川定义景观更明显的地方了。尽管这些收缩的冰块对海平面上升的贡献是无可争议的，但它们在更广泛的生物地球化学循环中的作用才刚刚开始揭示。当冰川融化时，它们会贡献大量的水，冰，沉积物和溶解的化学物质。格陵兰和南极洲周围的最近工作表明，冰川相关的养分和碳具有刺激在海洋食品网的基础上产生的，与食物链相关的相关影响（例如，当地的鱼类收获增强），以及通过更活跃的海洋生物泵在更广泛的碳循环上。然而，知识差距仍然存在从冰川系统中出口哪些人生元素，在海洋中发生的事情以及对海洋微生物群落的影响。这些知识中的差距没有比加拿大北极群岛（CAA）更明显的地方了，即在一个地区，冰川融化在海洋生物地球化学周期中的作用在很大程度上没有探索 - 尽管CAA是CAA是冰川恢复和融化河水径流的热点。 在接下来的5年中，我和我的小组将努力量化冰川系统中的营养和碳的出口，以及该出口对海洋过程和生态系统的相关影响。具体来说，我们会问：1）离开冰系统的生物地球化学成分（营养，碳）的来源是什么？ 2）冰川融化的命运及其在沿海海洋中的相关成分是什么？ 3）冰川融化如何影响海洋微生物社区的生产，结构和功能？为了回答这些问题，我们将进行新的冰山研究，将化学物种的现场测量与分子生物学测定和实验室实验相结合。这种方法将解决靠近冰川终端和更广泛的区域尺度的融合融合相互作用的影响，并针对未解决的机械问题。 HQP将使用跨学科技术，桥接海洋学，地球化学和微生物生态学来实现我的计划。我们将在CAA的琼斯声音中一起进行这项工作，CAA的琼斯声音被冰川包围，是Grise Fiord的Inuit Hamlet的所在地。这里的潮水冰川的末端是高效的水域，是小村庄的狩猎场。了解食品网络基础上海洋生产的驱动因素，以及这些驱动因素对气候变化的敏感性，对这个北方社区的长期健康以及沿海北极海洋的运作至关重要。总的来说，这项研究是揭示冰川在过去，现在和未来中融化冰川在海洋碳循环中的作用的关键步骤。