GEOTRACES Arctic Section: Processes affecting the biogeochemical cycling of essential and toxic metalloids in the Arctic Ocean

GEOTRACES 北极部分：影响北冰洋必需和有毒类金属生物地球化学循环的过程

• 批准号: 1435708
• 负责人: Gregory Cutter
• 金额: $ 23.84万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435708&HistoricalAwards=false
• 关键词: GEOTRACES; Arctic; Section; Processes; affecting

In this project, an investigator participating in the 2015 U.S. GEOTRACES Arctic expedition will establish the concentrations, chemical speciation, and cycling processes of arsenic and selenium 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. The metalloid elements arsenic and selenium to be studied in this project are toxic to many marine plants and animals, and their cycling in the Arctic is not well known. Thus, this project will have important implications for increased knowledge on the chemistry of these potentially toxic elements. Results from the project will be shared through outreach to Arctic residents and through a PolarTREC teacher who will participate in the cruise.The metalloid elements arsenic and selenium have dynamic marine cycles that affect the microbiology of the water column and in turn are affected by it. Both exist in multiple oxidation states and inorganic and organic species within an oxidation state. This chemical speciation affects their reactivity and biotic uptake and toxicity. As shown in lower latitude waters, the concentration and speciation of dissolved arsenic can control the abundance and types of primary producers. In the Arctic virtually nothing is known about arsenic cycling, although there are possibly enhanced anthropogenic inputs from Canadian rivers and atmospheric deposition. In contrast, data from the high latitude North Pacific Ocean and Bering Sea strongly suggest that anthropogenic selenium from coal combustion is entering the Arctic and enriching its concentration in at least one top predator. The goal of this project is to qualitatively describe the input, removal, and internal cycling processes affecting the speciation and concentrations of arsenic and selenium, and determine rates of inputs and outputs of these processes using both direct measurements and computations. The study will greatly expand knowledge about arsenic and selenium cycling, with strong implications for the changing Arctic.

在这个项目中，一名参与2015年美国GEOTRACES北极考察的研究人员将确定北冰洋中砷和硒的浓度、化学形态和循环过程。与国际GEOTRACES计划中的其他多国倡议一样，美国北极考察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量化通量，并确定这些分布对环境条件变化的敏感性。一些微量元素是生命所必需的，另一些是已知的生物毒素，还有一些是重要的，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。在这个项目中要研究的非金属元素砷和硒对许多海洋植物和动物是有毒的，它们在北极的循环并不为人所知。因此，该项目将对增加对这些潜在有毒元素的化学知识产生重要影响。该项目的成果将通过与北极居民的外展以及通过将参加巡航的PolarTREC教师进行分享。非金属元素砷和硒具有动态的海洋循环，影响水柱的微生物学，反过来又受其影响。两者都以多种氧化态存在，并在氧化态内存在无机和有机物种。这种化学形态影响它们的反应性和生物吸收和毒性。如在低纬度沃茨所示，溶解砷的浓度和形态可以控制初级生产者的丰度和类型。在北极，几乎没有什么是已知的砷循环，虽然有可能加强人为输入加拿大河流和大气沉积。相比之下，来自高纬度北太平洋和白令海的数据强烈表明，来自煤炭燃烧的人为硒正在进入北极，并在至少一种顶级捕食者中富集其浓度。本项目的目标是定性地描述影响砷和硒的形态和浓度的输入、去除和内部循环过程，并使用直接测量和计算来确定这些过程的输入和输出速率。这项研究将极大地扩展有关砷和硒循环的知识，并对北极的变化产生重大影响。