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.

在该项目中，参加2015年美国北极探险队的调查员将在北极海洋中建立砷和硒的浓度，化学物种形成和循环过程。美国北极探险队的目标是与国际地理计划计划中的其他跨国公司计划相同，是确定过程并量化流量，以控制海洋中关键的微量元素和同位素的分布，并确定这些分布对不断变化环境条件的敏感性。一些痕量元素对生命至关重要，另一些是已知的生物毒素，而另一些则很重要，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。该项目中要研究的金属元素砷和硒对许多海洋动植物有毒，并且它们在北极的循环尚不为人所知。因此，该项目将对增加对这些潜在有毒元素的化学知识的知识具有重要意义。该项目的结果将通过向北极居民以及将参加巡航的北极居民分享。金属元素砷和硒具有影响水柱微生物学的动态海洋周期，而它又受其影响。两者都存在于多种氧化态以及氧化状态内的无机和有机物种中。这种化学物种影响其反应性，生物摄取和毒性。如较低的纬度水域所示，溶解砷的浓度和形态可以控制主要生产者的丰度和类型。在北极，砷循环几乎一无所知，尽管加拿大河流和大气沉积的人为输入可能会增强。相比之下，来自北太平洋高纬度海洋和白令海的数据强烈表明，煤炭燃烧的人为硒正在进入北极，并在至少一个顶部捕食者中富集了其浓度。该项目的目的是定性地描述影响砷和硒的形成和浓度的输入，去除和内部循环过程，并使用直接测量和计算确定这些过程的投入和输出速率。这项研究将大大扩展有关砷和硒循环的知识，对北极变化的影响很大。