Collaborative Proposal: Unravelling the Oceanic Dimethylmercury Cycle

合作提案：揭示海洋二甲基汞循环

• 批准号: 2023046
• 负责人: Amina Schartup
• 金额: $ 37.07万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2023046&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Unravelling; Oceanic; Dimethylmercury

Collaborative Proposal: Unravelling the Oceanic Dimethylmercury CycleThis project will study how dimethylmercury is formed and removed in the oceans. Dimethylmercury is a naturally occurring compound. It is thought to be formed when man-made mercury is converted into monomethylmercury, a toxin that accumulates in fish. Despite representing a large fraction of mercury in the oceans, the origin and fate of dimethylmercury is not known. This research will use state-of-the-art analytical, genomic and modeling tools to address this information gap. It will also train graduate and undergraduate students to use field, experimental, and modeling methods. The results will be used in predictive models to forecast future trends in the oceanic mercury cycle. These models are needed to evaluate the effectiveness of international actions that seek to reverse increasing trends in the bioaccumulation of monomethylmercury in fish. Methylated mercury species in the ocean are formed in sediment and the water column from inorganic divalent mercury delivered from the atmosphere and rivers. The putative mechanism is a two-step process during which monomethylmercury is formed first, followed by slow methylation into dimethylmercury. The first step, biomethylation of divalent mercury into monomethylmercury, is relatively well-studied in sediment and known to be driven by sulfate- and iron-reducing bacteria and methanogens. The mechanism for monomethylmercury formation in the water column is less well understood, and the process of dimethylmercury formation in sediment or seawater is essentially unknown. Until recently, it was assumed that dimethylmercury represented a small enough fraction of the methylated and total mercury (the sum of all mercury species) pools to be insignificant in the global mercury cycle. Recent measurements, however, show that dimethylmercury levels in seawater can be in the same range as the other mercury species. This project will identify the biological and chemical methylating agents involved in the formation of dimethylmercury. Further, it will test the impact of varying biogeochemical conditions on dimethylmercury production. Results will be used to update the mercury module of the MIT General Circulation Model (MITgcm, a global biogeochemical model, and analyze the impacts of dimethylmercury production and degradation on monomethylmercury concentrations.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.

协作提案：揭开海洋二甲基汞环环项目将研究如何在海洋中形成和去除二甲基汞。二甲基汞是一种天然存在的化合物。 人们认为，当人造汞转化为单甲基汞时会形成，这是一种积聚在鱼类中的毒素。尽管在海洋中代表大量的汞，但二甲基汞的起源和命运尚不清楚。这项研究将使用最先进的分析，基因组和建模工具来解决此信息差距。它还将培训毕业生和本科生，以使用现场，实验和建模方法。结果将用于预测模型，以预测海洋汞周期的未来趋势。需要这些模型来评估国际行动的有效性，这些行动试图扭转鱼类单甲基汞生物积累的趋势。海洋中的甲基化汞物种是在沉积物中形成的，从大气和河流中传递的无机二价汞的水柱形成。推定的机制是一个两步的过程，在此过程中首先形成单甲基汞，然后慢慢地甲基化成二甲基汞。第一步是将二价汞的生物甲基化成单甲基汞，在沉积物中相对良好研究，已知是由硫酸盐和还原的细菌和甲基元素驱动的。水柱中单甲基汞形成的机制知之甚少，沉积物或海水中二甲基汞形成的过程本质上是未知的。直到最近，假定二甲基汞代表了足够小的甲基化和总汞（所有汞种类的总和）池在全球汞循环中微不足道的池。然而，最近的测量表明，海水中的二甲基水平可能与其他汞物种相同。该项目将确定与二甲基汞形成有关的生物学和化学甲基化剂。此外，它将测试不同生物地球化学条件对二甲基汞生产的影响。 Results will be used to update the mercury module of the MIT General Circulation Model (MITgcm, a global biogeochemical model, and analyze the impacts of dimethylmercury production and degradation on monomethylmercury concentrations.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.

项目成果

Methylmercury as a molecular imposter

甲基汞作为分子冒名顶替者

• DOI: 10.1038/s41557-021-00885-x
• 发表时间: 2022
• 期刊: Nature Chemistry
• 影响因子: 21.8
• 作者: Schartup, Amina T.

What are the likely changes in mercury concentration in the Arctic atmosphere and ocean under future emissions scenarios?

在未来的排放情景下，北极大气和海洋中的汞浓度可能会发生什么变化？

• DOI: 10.1016/j.scitotenv.2022.155477
• 发表时间: 2022
• 期刊: Science of The Total Environment
• 影响因子: 9.8
• 作者: Schartup, Amina T.;Soerensen, Anne L.;Angot, Hélène;Bowman, Katlin;Selin, Noelle E.
• 通讯作者: Selin, Noelle E.

Arctic mercury cycling

• DOI: 10.1038/s43017-022-00269-w
• 发表时间: 2022-03-22
• 期刊: NATURE REVIEWS EARTH & ENVIRONMENT
• 影响因子: 42.1
• 作者: Dastoor, Ashu;Angot, Helene;Zdanowicz, Christian
• 通讯作者: Zdanowicz, Christian