Collaborative Research: Iodine in Foraminifera as a proxy for ocean deoxygenation during the Paleocene-Eocene Thermal Maximum

随着全球变暖的进展，海洋中的氧气水平预计将下降，这可能会对海洋生物造成严重影响。为了预测未来海洋氧气水平的变化，需要更好地了解与过去变暖事件相关的脱氧作用。这项由锡拉丘兹大学和耶鲁大学的研究人员合作的项目将在海底有孔虫测试中使用碘作为过去氧气条件的新替代品。这项研究的动机是氧化还原条件与海水中的碘酸盐(IO3-)浓度之间的密切关系，这些因素会影响有孔虫测试中的I/Ca值。该项目将扩大前期工作，以便更好地校准碘替代物，然后将其应用于古新世-始新世最高温度(PETM)的研究，这是一种发生在约5500万年前的变暖事件。研究人员将利用海洋钻探计划从大西洋、太平洋和印度洋盆地以及地中海、美国东部和新西兰的陆地部分收集的岩芯中的海底有孔虫，重建PETM期间海洋氧合作用的时间、水深和地理变化。此外，他们将研究缺氧和海底生物灭绝之间的联系，并考虑缺氧/缺氧的模式，以评估哪些因素(例如，温度、生产力、循环、当地甲烷氧化)对低氧条件的发展影响最大。研究人员将与德国(GEOMAR)和英国(牛津)的机构在代理改进方面进行国际合作，并将通过耶鲁气候与能源研究所等场所与政策制定者接触。资金将支持一名职业生涯早期的研究人员；此外，该项目还将培训一名博士、一名硕士和两名本科生。该项目将让代表不足的高中生通过进化，这是美国国家科学基金会资助的耶鲁皮博迪博物馆的课后项目。结果将被纳入大学课程和针对本科生的展览。

Oxygen levels in the ocean are expected to decrease as global warming progresses, with potentially serious implications for marine life. To forecast future changes in ocean oxygen levels, a better understanding is needed of deoxygenation associated with past warming events.This project, a collaboration between researchers at Syracuse and Yale Universities, will use iodine in benthic foraminiferal tests as a novel proxy for past oxygenation conditions. The research is motivated by the a close relationship between redox conditions and iodate (IO3-) concentrations in seawater, which affect I/Ca values in foraminiferal tests. The project will expand upon preliminary work in order to better calibrate the iodine proxy, then apply it to a study of the Paleocene-Eocene Thermal Maximum (PETM), a warming event that occurred ~55 million years ago. The researchers will reconstruct temporal, bathymetric, and geographic variations in ocean oxygenation during the PETM, using benthic foraminifera in cores collected by the Ocean Drilling Program from the Atlantic, Pacific, and Indian Ocean basins, as well as land sections from the Mediterranean, eastern U.S., and New Zealand. In addition, they will examine the link between deoxygenation and benthic extinctions, and consider patterns of hypoxia/anoxia to assess which factors (e.g., temperature, productivity, circulation, local methane oxidation) most influenced the development of low oxygen conditions.The researchers will collaborate internationally on proxy refinement with institutions in Germany (GEOMAR) and the UK (Oxford), and will engage policy makers through venues like the Yale Climate and Energy Institute. Funding will support an early-career investigator; additionally, the project will train one PhD, one MS, and two undergraduate students. The project will involve underrepresented high school students through EVOLUTIONS, an NSF-funded after-school program at the Peabody Museum (Yale). Results will be incorporated into university coursework and exhibits targeted at undergraduates.