Collaborative Research: Three decades of foraminiferal assemblages in the Santa Barbara Basin provide a link between present and past

现代温室气体二氧化碳向大气中的排放量是过去3000万年来最高的。这导致了海洋的重大变化。这项工作的重点是使用一组贝壳形成生物，浮游有孔虫。有孔虫的碳酸盐壳存在于海底沉积物中。它们提供了它们生长环境的历史。该项目的目标是利用有孔虫的贝壳更好地了解不同有孔虫物种的丰度随着气候变化的速度和原因。从加利福尼亚州圣巴巴拉盆地收集的储存样本将创造30年来浮游有孔虫丰度的记录。结果将与现代海洋学测量和在较老的海底沉积物中发现的有孔虫有关。这将使人们能够更好地了解气候变化在很长一段时间内如何影响海洋环境，并使未来能够进行预测。该项目将为学生提供实践研究培训。将开展课堂活动，促进使用真实世界数据集的量化和数据可视化技能。有孔虫具有特定物种的环境偏好，这会影响它们在水柱和海洋沉积物中的组合。此外，有孔虫贝壳的地球化学已成为广泛使用的古海洋学指标的基础。然而，对化石有孔虫记录的解释必须从根本上建立在有孔虫生态学的基础上。例如，地球化学指标的使用依赖于季节性或生境随时间的变化可以忽略不计的假设，违规行为可能导致古海洋学记录中的关键错误。除了评估有孔虫动物群变化的速率和驱动因素外，这项研究还将实现以下目标：1)测试季节性变化如何影响基于有孔虫的替代记录的解释；2)评估沉积物圈闭动物群是否具有下伏沉积物的代表性；3)将21世纪有孔虫动物群变化与地质记录相结合。为实现这些目标，将产生来自每两周一次的沉积物捕捉器的组合和来自沉积物岩心的近一年分解的样品。选择圣巴巴拉盆地是因为它拥有沉积物圈闭材料的档案，广泛的重叠观测数据，保存完好的化石记录，以及经历从季节性到人为和更长时间的气候振荡。定量组合将得到壳体子集的稳定同位素和痕量元素分析的支持，以测试地球化学替代记录的解释。该奖项反映了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。

Modern day releases of the greenhouse gas, carbon dioxide, into the atmosphere are the highest observed over the last 30 million years. This has resulted in major changes in the ocean. This work focuses on using a group of shell-forming organisms, planktic foraminifera. The carbonate shells of foraminifera are found in seafloor sediments. They provide a history of the environment in which they grew. The goal of this project is to use the shells of foraminifera to better understand how quickly and why the abundances of different foraminifera species change in response to climate. A thirty-year record of planktic foraminifera abundances will be created from stored samples collected from the Santa Barbara Basin, California. The results will be connected to modern day oceanographic measurements and the foraminifera found in older seafloor sediments. This will allow a better understanding of how climate change has impacted the ocean environment over very long time periods and allow future predictions. This project will provide hands on research training for students. Classroom activities will be developed that promote quantitative and data visualization skills with a real-world dataset. Foraminifera have species-specific environmental preferences that influence their assemblages in the water column and in marine sediments. Moreover, the geochemistry of foraminiferal shells has become the foundation for widely used paleoceanographic proxies. However, interpretation of the fossil foraminiferal record must be fundamentally grounded in foraminiferal ecology. For example, use of geochemical proxies relies on the assumption of negligible change in seasonality or habitat through time, with violations potentially responsible for key errors in the paleoceanographic record. In addition to assessing rates and drivers of foraminiferal faunal change, this research would fulfill goals including: 1) testing how changing seasonality influences interpretations of foraminiferal-based proxy records, 2) evaluating whether sediment trap faunas are representative of underlying sediment, and 3) integrating 21st century foraminiferal faunal change with the geological record. Assemblages from biweekly sediment traps and near-annually resolved samples from a sediment core will be generated to accomplish these goals. Santa Barbara Basin was chosen because it has an archive of sediment trap material, extensive overlapping observational measurements, a well-preserved fossil record, and experiences climatic oscillations at timescales from seasonal to anthropogenic and longer. Quantitative assemblages will be supported by stable isotope and trace elemental analyses of a subset of shells to test interpretations of geochemical proxy records.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.