Collaborative Research: US GEOTRACES GP17-OCE and -ANT Sections: External sources, cycling and processes affecting mercury in the South Pacific and Southern Oceans

合作研究：US GEOTRACES GP17-OCE 和 -ANT 部分：影响南太平洋和南大洋汞的外部来源、循环和过程

• 批准号: 2152649
• 负责人: Silvia Newell
• 金额: $ 37.85万
• 依托单位: Wright State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2152649&HistoricalAwards=false
• 关键词: Collaborative; Research; US; GEOTRACES; GP17

This project will evaluate the concentrations of mercury (Hg) in its various forms in the ocean and atmosphere to examine the factors that control its concentration and chemistry in remote regions of the ocean. The proposed work will examine mercury sources, primarily from the atmosphere, and how mercury is finally removed from ocean waters. Specifically, this study is focused on the South Pacific and Southern Ocean around Antarctica, regions that are remote from human activity and their associated Hg inputs to the biosphere. Human activity has substantially enhanced the amount of Hg in the biosphere and its levels in seafood consumed by humans, and therefore their potential exposure, but its impact in these remote regions is poorly constrained. The measurements will be made during two ocean expeditions that form part of the international GEOTRACES program. GEOTRACES aims to examine the concentrations and distributions of trace elements and their isotopes in the atmosphere, surface and deep oceans of the world. Mercury is a primarily a concern because of its ability to bioaccumulate in marine food chains, primarily in its organic form, methylmercury (MeHg). Elevated levels of MeHg in fish and other marine organisms is a concern for human and wildlife health due to exposure through seafood consumption, and the factors controlling this exposure are not well understood. The proposed work will support three graduate and several undergraduate students across the three participating institutions.During the two expeditions, the research team will collect high resolution data on the concentrations of the primary Hg forms in the atmosphere, the water column, and the sediments, to examine the sources of Hg to these regions and the processes that lead to the conversion of Hg to its more toxic and bioaccumulative form, MeHg. Dissolved and particulate forms of the various Hg species (gaseous elemental Hg, ionic Hg, MeHg and dimethylmercury) will be determined in the atmosphere and throughout the water column using high resolution sampling and novel techniques. Additionally, measurements of Hg stable isotopes in atmospheric and water samples will be used to identify sources (e.g., geogenic or anthropogenic inputs) and delivery mechanisms (e.g., dry or wet deposition, glacial melt) of Hg to these regions. This comprehensive project will leverage Hg speciation and Hg source tracking capabilities to assess the importance of human activity and climate change in altering the amount of Hg and MeHg in these ocean waters, and the resultant levels in marine organisms consumed by humans.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目将评估其在海洋和大气中各种形式的汞浓度（HG），以检查控制其偏远地区浓度和化学的因素。拟议的工作将主要从大气中研究汞来源，以及如何最终从海水中取出汞。具体而言，这项研究集中在南极附近的南太平洋和南大洋上，这些区域远离人类活动及其与生物圈相关的HG输入。人类活动大大提高了生物圈中的HG量及其在人类消耗的海鲜中的水平，因此它们的潜在暴露量，但其在这些偏远地区的影响受到了很大的约束。这些测量将在构成国际地理计划一部分的两次海洋探险中进行。 Geotraces旨在检查世界大气，表面和深海中痕量元素及其同位素的浓度和分布。汞主要是一个关注点，因为它具有在海洋食品链中生物蓄积的能力，主要是有机形式的甲基汞（MEHG）。鱼类和其他海洋生物的MEHG水平升高，这是人类和野生动植物健康的关注，这是由于海鲜消耗而暴露的，并且控制这种暴露的因素尚不清楚。拟议的工作将支持三个参与机构的三名毕业生和几名本科生。在两次探险中，研究团队将收集有关大气中主要HG形式的浓度的高分辨率数据，水柱，水柱和沉积物，以检查HG到这些地区的HG来源，并导致HG对其有毒和BioCaccic和BioCCCC的对象，并将其更加有毒。使用高分辨率采样和新技术，将在大气和整个水柱中确定各种HG物种（气态元素HG，Ionic HG，MEHG和Dimethylmercury）的溶解和颗粒形式。此外，将使用大气和水样品中HG稳定的同位素的测量来鉴定来源（例如，地球或人为输入）和向这些区域的HG的递送机制（例如，干燥或湿沉积，干燥或湿的沉积，冰川融化）。 This comprehensive project will leverage Hg speciation and Hg source tracking capabilities to assess the importance of human activity and climate change in altering the amount of Hg and MeHg in these ocean waters, and the resultant levels in marine organisms consumed by humans.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.