Collaborative Research: GEOTRACES Arctic Section: Mercury Speciation and Cycling in the Arctic Ocean

合作研究：GEOTRACES 北极部分：北冰洋的汞形态和循环

• 批准号: 1434653
• 负责人: Carl Lamborg
• 金额: $ 39.37万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1434653&HistoricalAwards=false
• 关键词: Collaborative; Research; GEOTRACES; Arctic; Section

In this project, investigators from Woods Hole Oceanographic Institution and Wright State University participating in the 2015 U.S. GEOTRACES Arctic expedition will measure total mercury and mercury species in seawater, particles, sediments, snow and sea-ice samples to better understand its cycling in the Arctic Ocean. In common with other multinational initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. Some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. In its methylated form, mercury poses a serious human and ecosystem health threat, and this research will provide important information on the extent and rate of change of mercury in the sensitive Arctic ecosystem. Results from this study will be shared through outreach efforts to middle schools students in the Dayton, Ohio area, and the research will involve training for graduate and undergraduate students.Mercury is a toxic trace metal that originates from natural and anthropogenic sources, and can enter the oceans through many processes, most importantly atmospheric deposition, riverine discharge, and coastal erosion in the Arctic Ocean. Mercury in the ocean can be transformed into varying species by a variety of abiotic and biotic processes. Its transformation to methylmercury is of primary concern as it can biomagnify in food webs. Wildlife in the Arctic has experienced unprecedented increases of methylmercury in their tissues during the past 200 years. While there has been a great deal of research related to mercury cycling in the Arctic in recent years, there remain large gaps in fundamental understanding, particularly with respect to mercury distributions and speciation. The researchers will 1) measure the concentration of four mercury species in the water column, particles, sediments, snow and sea-ice samples, 2) determine the concentration of other related chemical species (thiols and snow/ice bromine), and 3) explore the mercury-related genomics of bacteria in various samples. Results from this work will yield new insights into the extent and rate of change of mercury loadings in the Arctic Ocean.

在这个项目中，来自伍兹霍尔海洋研究所和莱特州立大学的研究人员将参与2015年美国地理痕迹北极探险，他们将测量海水、颗粒、沉积物、雪和海冰样本中的总汞和汞物种，以更好地了解其在北冰洋的循环。与国际地质勘测计划中的其他多国倡议一样，美国北极探险的目标是确定控制海洋中关键微量元素和同位素分布的过程和通量，并确定这些分布对不断变化的环境条件的敏感性。一些微量元素对生命是必不可少的，另一些是已知的生物毒素，还有一些很重要，因为它们可以用作海洋中各种物理、化学和生物过程的示踪剂。汞的甲基化形式对人类和生态系统健康构成严重威胁，这项研究将提供有关敏感北极生态系统中汞变化程度和速度的重要信息。这项研究的结果将通过推广到俄亥俄州代顿市的中学生中分享，这项研究将包括对研究生和本科生的培训。汞是一种有毒的痕量金属，来自自然和人为来源，可以通过许多过程进入海洋，最重要的是北冰洋的大气沉积、河流排放和海岸侵蚀。海洋中的汞可以通过各种非生物和生物过程转化为不同的物种。它转化为甲基汞是人们主要关注的问题，因为它可以在食物网中进行生物放大。在过去的200年里，北极野生动物的组织中甲基汞的含量出现了前所未有的增长。虽然近年来有大量关于北极汞循环的研究，但在基本认识上仍存在很大差距，特别是在汞的分布和形态方面。研究人员将1)测量水柱、颗粒、沉积物、雪和海冰样本中四种汞物种的浓度，2)确定其他相关化学物种(硫醇和雪/冰溴)的浓度，3)探索各种样本中与汞有关的细菌基因组学。这项工作的结果将对北冰洋汞负荷的变化程度和速度产生新的见解。