Collaborative Research: Defining the Role of Biologically Produced Reactive Oxygen Species in Dark Mercury Cycling

汞（Hg）是一种有毒的微量元素，可通过生物积累进入海洋食物网，通过食用海产品对人类的健康构成威胁。然而，人们对海洋中汞循环的控制知之甚少。迄今为止，大多数研究都集中在阳光照射和/或含汞环境中，在这些环境中，光诱导的化学反应和抗汞反应分别被确定为汞循环的主要途径。暗汞反应无关的范例正在消失，现在很明显，暗氧化还原反应，还原和氧化，在汞的循环中都很重要。在这项研究中，伍兹霍尔海洋研究所和科罗拉多矿业学院的研究人员将更好地了解海洋系统中汞（Hg）暗氧化还原转化的生物地球化学反应。研究人员将在一系列实验室和野外调查中探索微生物活动、活性氧和汞形态之间的关系，以获得对暗汞循环的机制理解。通过确定海洋中汞氧化还原循环的新控制，本研究将有助于为用于预测汞生物可利用性的全球和生态系统模型提供信息。更广泛的影响：支持者计划对波士顿南部的波士顿绿色学院的高中教师进行汞生物地球化学方面的教育，并让一名教师参加夏季研究游船，同时开发科学课程，让学校中代表性不足的学生参与科学。作为该项目的一部分，伍兹霍尔海洋研究所的一名博士后和一名研究生以及科罗拉多矿业学院的一名研究生将得到支持和培训。预计本科生将有机会以暑期实习生的身份参与研究。

Mercury (Hg) is a toxic trace element that bioaccumulates into marine food webs, imposing a health threat to humans through the consumption of seafood. However, controls on the cycling of Hg in the ocean are poorly understood. Most research to date has focused on sun-lit and/or Hg-laden environments, where light-induced chemical and mercury resistance reactions, respectively, have been identified as dominant pathways for Hg cycling. The paradigm that dark Hg reactions are irrelevant is fading and it is now apparent that dark redox reactions, both reduction and oxidation, are important in the cycling of Hg. In this study, researchers at the Woods Hole Oceanographic Institution and Colorado School of Mines will obtain a better understanding of the biogeochemical reactions responsible for dark redox transformations of mercury (Hg) in marine systems. The researchers will explore the relationship between microbial activity, reactive oxygen species, and Hg speciation in a series of laboratory- and field-based investigations to obtain a mechanistic understanding of dark Hg cycling. By identifying new controls on the redox cycling of Hg in the ocean, this research will help inform global and ecosystem models used to predict Hg bioavailability.Broader Impacts: The proponents plan to educate high school teachers from Boston Green Academy in South Boston on mercury biogeochemistry and have one teacher participate in the summer research cruises, as well as develop science curricula to engage the underrepresented students at the school in science. One postdoc and one graduate student from Woods Hole Oceanographic Institution and one graduate student from the Colorado School of Mines would be supported and trained as part of this project. It is anticipated that undergraduate students would have the opportunity to participate in the study as summer interns.