Collaborative Research: Constraining Planktic Foraminiferal Ecology Using Compound Specific Isotope Analysis of Amino Acids

合作研究：利用氨基酸的复合特定同位素分析来限制浮游有孔虫生态

• 批准号: 2303608
• 负责人: Catherine Davis
• 金额: $ 29.51万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2303608&HistoricalAwards=false
• 关键词: Collaborative; Research; Constraining; Planktic; Foraminiferal

Current climate change is unique in human history. To understand how the Earth and life on it responds to comparable change it is necessary to look millions of years in the past. A huge amount of what we know about past climate comes from the fossils of marine plankton. Specifically, a group of single-celled organisms called foraminifera. Foraminifera make tiny fossil shells which capture the chemistry of the water they grew in. As a result, they can be used to reconstruct ancient ocean waters and climate. To use the fossil shells of foraminifera to their greatest effect, the ecology of the living creature must be understood. Variables like what the foraminifera ate, what depth it lived at, and whether it had symbionts will all impact how shell chemistry is interpreted. Compound-specific nitrogen and carbon isotopes of specific amino acids (CSI-AA) represent a unique approach to study these variables in living plankton. This proposal would test how well this approach can be applied to fossil shells. If successful, this would provide powerful ways to describe the ecology of long extinct planktic foraminifera. In doing so, one may better understand the records they hold of Earth’s past. The project broader impacts include support for a postdoctoral researcher, development of a career-opportunities workshop to introduce students from Primarily Undergraduate Institutions to geoscience research, and content contributions to a summer program for at-risk STEM transfer students at UC Santa Cruz. Specifically, this project will investigate and develop multiple aspects of CSI-AA to better understand the species-level ecology of planktic foraminifera. This is key to generating paleoclimate and paleoceanographic records that can contextualize the Ocean’s future climate and trajectory. The proposed project will use CSI-AA to constrain three key aspects of planktic foraminiferal ecology: depth habitat, diet, and symbiosis. CSI-AA from shell-bound organics will be used in foraminifera for the first time to refine species-level inferences about these ecological traits. First CSI-AA applications in extant species will be ground-truthed using plankton tows, sediment traps, and recent sedimentary samples from the Santa Barbara Basin. Lessons learned will then be applied deeper into the fossil record to elucidate the trophic ecology of extinct foraminifera. Finally, amino acid molar ratios and racemization (the diagnostic shift between amino acid forms which occurs with fossil age) will be used to assess amino acid preservation in fossils and ultimately test the limits of this approach by targeting a suite of abundant species from the Miocene, Eocene, and Cretaceous.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

当前的气候变化在人类历史上是独一无二的。要了解地球和生命如何应对可比的变化，有必要在过去看数百万年。我们对过去气候的了解大量来自海洋浮游生物的化石。具体而言，一组称为有孔虫的单细胞生物。有孔虫制作微小的化石壳，以捕获其生长的水的化学反应。因此，它们可用于重建古老的海水和气候。要使用有孔虫的化石壳达到其最大的作用，必须理解生物的生态。变量像有孔虫的食物，它的深度以及它是否具有符号都会影响壳化学的解释方式。特异性氨基酸（CSI-AA）的化合物特异性氮和碳同位素代表了研究这些变量活浮游生物的独特方法。该建议将测试该方法如何应用于化石壳。如果成功，这将提供有力的方法来描述长期灭绝的浮游有孔虫的生态。这样一来，人们可能会更好地了解他们持有地球过去的记录。该项目更广泛的影响包括对博士后研究人员的支持，开发职业发展的研讨会，以介绍主要是本科机构的学生来介绍地球科学研究的学生，以及对UC Santa Cruz的高危STEM转移学生的夏季计划的内容贡献。具体而言，该项目将调查和发展CSI-AA的多个方面，以更好地了解浮游有孔虫的物种水平的生态学。这是产生古气候和古洋野系统记录的关键，可以使海洋未来的气候和轨迹背景下背景。拟议的项目将使用CSI-AA来限制浮游有孔虫生态学的三个关键方面：深度栖息地，饮食和符号。来自壳体结合有机物的CSI-AA将首次在有孔虫中使用，以完善有关这些生态特征的物种级别的信息。首先，使用浮游生物烟，沉积物陷阱和来自圣塔芭芭拉盆地的最近的沉积样品对广泛物种中的第一个CSI-AA应用。然后，所学的经验教训将更深入地应用于化石记录中，以阐明灭绝有孔虫的营养生态。最后，将使用氨基酸摩尔比和种族化（与化石年龄发生的氨基酸形式之间的诊断转移）用于评估化石中的氨基酸保留，并最终通过针对中新世，尤其固奖的构成宣传的构建奖，并通过构建了该方法来测试这种方法的局限性。优点和更广泛的影响审查标准。