Collaborative Research: Foraminiferal Ecological Response to Ocean Conditions in the Northwest Pacific Ocean

有孔虫是生活在海洋中的微小的有壳原生动物。它们贝壳的化学成分在生长过程中会随着海洋条件的变化而变化。海底常见的有孔虫化石被用来重建过去的海洋条件和地球的气候历史。新的数据显示，东北太平洋存在的有孔虫物种组合正在迅速变化，以应对海洋变暖事件，即通常所说的海洋热浪。这项研究将提高我们在古气候研究中利用温带和高纬度物种的能力。它还将有助于量化现代气候变化如何改变该地区存在的物种。这项研究将包括在浮游生物网和沉积物捕集器中收集标本。它将量化沉积物捕集器部署过程中存在的物种，并将它们贝壳的组成与它们生长时的海洋条件进行比较。少量标本将在实验室中培养，更多的标本将用于遗传分析。该项目将有助于展示现代海洋条件如何影响该地区物种的组合，以及生长条件如何影响贝壳的组成。该项目将支持俄勒冈州立大学的两名研究生以及俄勒冈州立大学和南卡罗来纳大学的多名本科生。来自该研究项目的有孔虫贝壳将在MicroCT扫描仪上成像，以生成3D图像。这些图像随后将提供给更广泛的社区用于研究和教学目的。该项目将提高温带和高纬度浮游有孔虫在古气候研究中的效用，并量化现代气候变化对东北太平洋有孔虫组合的影响。主要目标是扩大我们对温带和高纬度有孔虫物种地球化学的生态学和环境控制的知识，量化它们对海洋条件(特别是海洋热浪)现代变化的反应，并在它们沉入海底时限制有孔虫的地球化学特征。这将通过大量的现场和实验室工作来实现，其中包括新收集的浮游生物拖网、短期船基养殖实验、从存档的浮游生物拖网样本中收集数据，以及部署两个系泊沉积物捕集器。拟议的多管齐下的采样战略将提供了解这一重要海洋边缘地区有孔虫的生物地球化学和生态所需的关键样本，增加它们在了解过去海洋条件方面的效用，并为了解高纬度物种将如何应对未来气候变化奠定基础。高度受控的养殖实验将量化温带到极地物种中微量元素掺入的动力学和导致贝内微量元素变异的机制。这些实验结果将为解释温带到高纬度地区有孔虫化石的地球化学提供重要信息，拓宽我们对高纬度和温带有孔虫物种中微量元素掺入控制的理解，并提高它们在古海洋重建中的实用性。将对沉积物捕集器、浮游生物拖曳和养殖标本进行微量元素和同位素组成的分析。将对活体捕获的样本进行分析，以确定它们的基因和微生物组。有孔虫和沉积物捕集器样本将被存档在俄亥俄州立大学海洋地质库，以供科学界未来研究。这一裁决反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Foraminifera are tiny, shelled protists that live throughout the ocean. The chemical composition of their shells varies as a function of the ocean conditions during growth. Fossil foraminifera, which are common on the seafloor, are used to reconstruct past ocean conditions and Earth’s climate history. New data show that the mix of foraminifera species present in the Northeast Pacific Ocean is changing rapidly in response to ocean warming events, commonly referred to as marine heat waves. This study will improve our ability to use temperate and high-latitude species in paleoclimate research. It will also help quantify how modern climate change is modifying the species present in this region. The study will include collecting specimens in plankton nets and sediment traps. It will quantify the species present during the sediment trap deployment and will compare the composition of their shells to ocean conditions when they grew. A small number of specimens will be grown in the laboratory and additional specimens will be used for genetic analyses. This project will help show how modern ocean conditions impact the mix of species present in this region and how growth conditions influence the composition of their shells. This project will support two graduate students at Oregon State University (OSU) and multiple undergraduate students at OSU and at the University of South Carolina. Foraminifera shells from this research project will be imaged on a MicroCT scanner to generate 3D images. Those images will then be made available to the broader community for research and teaching purposes. The project will improve the utility of temperate and high-latitude planktic foraminifera in paleoclimate research and quantify the effects of modern climate change on foraminifera assemblages in the Northeast Pacific Ocean. The main objectives are to expand our knowledge of the ecology and environmental controls on the geochemistry of temperate and higher-latitude foraminifera species, quantify their response to modern changes in oceanographic conditions (specifically marine heat waves), and constrain foraminiferal geochemical signatures as they sink to the seafloor. This will be achieved through a significant field-based and laboratory effort that includes newly collected plankton tows, short-duration ship-based culture experiments, assemblage data from archived plankton tow samples, and the deployment of two moored sediment traps. The proposed multi-pronged sampling strategy will provide critical samples needed to understand the biogeochemistry and ecology of foraminifera in this important ocean margin region, increase their utility in understanding past oceanographic conditions, and lay the groundwork for understanding how high-latitude species will respond to future climate change. Highly controlled culture experiments will quantify trace element incorporation dynamics and mechanisms responsible for intrashell trace element variability in temperate to polar species. The results of these experiments will offer important information that can be used to interpret the geochemistry of fossil foraminifera in temperate to high-latitude regions, broaden our understanding of the controls on trace element incorporation in high-latitude and temperate foraminifera species, and improve their utility in paleoceanographic reconstructions. Sediment trap, plankton tow, and cultured specimens will be analyzed for their trace element and isotopic composition. Live captured specimens will be analyzed to determine their genotype and microbiome. Foraminifera and sediment trap samples not used by the PIs in this project will be archived at the OSU Marine Geological Repository for future studies by the scientific community.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.