Biogeochemistry of trace metals in Canada's subarctic and Arctic oceans under a rapidly changing climate

快速变化的气候下加拿大亚北极和北冰洋微量金属的生物地球化学

• 批准号: RGPIN-2020-06203
• 负责人: Cullen, Jay
• 金额: $ 2.62万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741090
• 关键词: Biogeochemistry; trace; metals; Canada; subarctic

The oceans provide ecosystem services that benefit all Canadians but these services are increasingly threatened by human activity. Two of these services at risk are the sequestration of atmospheric carbon dioxide through photosynthesis, which helps to mitigate climate change, as well as the production of food through our fisheries. Photosynthetic marine microbes provide these services because they consume CO2 and form the base of the marine food web. As a maritime nation, understanding what controls the growth of marine microbes and thereby the services the marine environment provides has clear economic and cultural relevance for Canadians. Trace metals are elements that are found in very small concentrations in seawater either because they are rare on our planet or because they are rapidly removed from the ocean by chemical and/or biological processes. The amount and chemical form of trace metals in seawater can prevent photosynthetic microbes from growing either because they are essential limiting nutrients, or they are toxins when too abundant. Ultimately, metals can control the oceans ability to take up greenhouse gases and slow climate change. Similarly, the health and sustainability of our fisheries can depend on the biological availability of metal nutrients and toxins. So, while trace metals are not abundant in the ocean they have impacts that are much greater than their small concentrations might suggest. My research group develops and uses highly sensitive analytical tools to study trace metal chemistry in the ocean. The long-term goals of my research program are to understand the processes that control the distribution, chemical form and resulting availability of trace metals to microbes, and how climate change is likely to impact trace metal chemistry in the future. We focus on metals that control primary production and microbe community structure (e.g. iron, copper and zinc), serve as paleoceanographic tracers that provide important information regarding the oceans role is past climate change (e.g. silver, cadmium), or potentially toxic heavy metals that might negatively impact the marine ecosystem (copper, silver and cadmium). Over the next 5 years my short term research objectives are to: 1) examine how changing temperature, ocean acidification and light where sea ice melts in high latitude ocean surface waters will impact biologically important metals; 2) unravel how much metals are either added or removed from the ocean near the continents; and 3) determine how decreasing oxygen levels in the ocean impact the relative distribution of metals. Our data will allow for better incorporation of metal chemistry in computer models designed to predict the response of marine services that benefit Canadians to climate change. This understanding will allow policy makers to make effective plans to moderate and mitigate ongoing human caused climate change and to sustainably manage and steward our marine resources into the future.

海洋提供生态系统服务，使所有加拿大人受益，但这些服务越来越受到人类活动的威胁。这些处于危险中的服务中有两种是通过光合作用将大气二氧化碳固定，这有助于减轻气候变化以及通过我们的渔业生产食物。光合海洋微生物提供这些服务，因为它们消耗了二氧化碳并构成了海洋食品网的基础。作为一个海洋国家，了解什么控制了海洋微生物的增长，因此海洋环境提供的服务对加拿大人具有明显的经济和文化意义。痕量金属是在海水中发现的元素，因为它们在我们的星球上很少见，或者是因为它们通过化学和/或生物过程迅速从海洋中移走。海水中痕量金属的数量和化学形式可以防止光合微生物生长，因为它们是必不可少的养分，或者在过多时是毒素。最终，金属可以控制海洋占用温室气体和气候变化缓慢的能力。同样，渔业的健康和可持续性可以取决于金属养分和毒素的生物学可用性。因此，尽管痕量金属在海洋中并不丰富，但它们的影响远大于其少量浓度。 我的研究小组开发并使用高度敏感的分析工具来研究海洋中的痕量金属化学。我的研究计划的长期目标是了解控制微生物的分布，化学形式以及导致金属可用性的过程，以及气候变化如何影响未来的痕量金属化学反应。我们专注于控制一级生产和微生物群落结构（例如铁，铜和锌）的金属，作为古环摄影示踪剂，提供有关海洋角色的重要信息是过去的气候变化（例如，银，镉）或可能对海洋生态系统（铜，银和碳）产生负面影响的可能性有毒的重金属。在接下来的5年中，我的短期研究目标是：1）检查温度，海洋酸化和光线如何在高纬度海面水中融化的海冰会影响生物学上重要的金属； 2）解散从大洲附近的海洋中添加或去除多少金属； 3）确定海洋中的氧气水平降低如何影响金属的相对分布。我们的数据将允许在计算机模型中更好地纳入金属化学，以预测有益于加拿大人对气候变化的海洋服务的响应。这种理解将使政策制定者能够制定有效的计划，以适应和减轻正在进行的人类导致气候变化，并可持续地管理和管理我们的海洋资源到未来。