Collaborative Research: Experimental constraints on marine Fe isotope effects - Biology, ligands, and particles

铁是海洋浮游植物必需的微量营养素，在全球碳循环和海洋生态系统中起着关键作用，有必要更好地了解海洋中这种必需微量营养素的来源和汇。铁同位素是近年来发展起来的铁生物地球化学循环示踪剂，新的铁同位素结果表明，铁结合配体可能在溶解铁的同位素分馏中起关键作用。然而，目前，铁溶解或生物铁摄取在海洋中溶解铁同位素分馏中的定量重要性尚不清楚。在这项研究中，来自南卡罗来纳大学和百慕大海洋科学研究所的研究人员将从百慕大大西洋时间序列站（BATS）收集和分析样本，以便；1)测量天然铁结合配体存在下天然气溶胶和含氧沉积物中铁溶解的速率和同位素分馏；2)研究浮游植物在生物吸收过程中如何分解铁同位素。本研究结果将推动铁同位素作为海洋铁生物地球化学循环追踪工具的发展。更广泛的影响：该项目将为本科生、研究生和博士后提供科学培训和发展。这项研究的结果将通过一个网页、外联活动和百慕大海洋科学研究所的公众参观来提高公众对生物地球化学科学的认识。

Iron is an essential micronutrient for marine phytoplankton, which plays a key role in the global carbon cycle and marine ecosystems, and there is a need to better understand the sources and sinks of this essential micronutrient in the oceans. Iron isotopes are a recently developed tracer of iron biogeochemical cycling, and new iron isotope results indicate that iron-binding ligands may play a critical role in the isotopic fractionation of dissolved iron. At present, however, the quantitative importance of iron dissolution or biological iron uptake in the isotopic fractionation of dissolved iron in the oceans is not well-known. In this study, researchers from the University of South Carolina and the Bermuda Institute of Ocean Sciences will collect and analyze samples from the Bermuda Atlantic Time-series Station (BATS) in order to; 1) measure the rate and isotope fractionation of iron dissolution from natural aerosols and oxic sediments in the presence of natural iron-binding ligands, and; 2) examine how phytoplankton fractionate iron isotopes during biological uptake. Results from this study will advance the development of iron isotopes as a tool for tracing iron biogeochemical cycling in the oceans.Broader Impacts: The project will provide scientific training and development to undergraduate, graduate, and postdoctoral students. Results of the study will be used to raise public awareness of biogeochemical science via a webpage, outreach activities, and public tours at the Bermuda Institute of Ocean Sciences.