Temperature and Carbonate System Influences on the Test Chemistry of Deep-Sea Benthic Foraminifera: Laboratory Culture Studies

海底有孔虫贝壳成分的岩心记录可以提供过去深水温度和化学成分的宝贵记录。虽然现场校准研究已经确定了贝壳化学和底层水条件之间的关系，但我们解释海底有孔虫替代记录的能力仍然受到挑战，因为多种因素--环境和生物--可以影响贝壳化学的大多数方面。基于文化的研究为核心-顶层校准提供了一个有希望的补充，因为在实验室中，可以在保持其他环境变量不变的情况下改变单个环境变量。这项研究建立在之前资助的培养工作的基础上，这里重点展示了乌维埃里纳和轮虫这两个在古海洋学中广泛使用的底栖有孔虫物种在培养中的钙化以及在培养中的繁殖和随后的生长。从大西洋中部边缘采集的样品将在受控和监测的物理和化学条件下进行培养，以评估新形成的壳体材料中有孔虫的氧同位素值的一致性。重点放在有孔虫的生长和繁殖上，这将为未来在不同环境条件下进行代理校准奠定重要基础。一名女性博士后研究员将在该项目中发挥核心作用。其他更广泛的影响包括为来自非海洋机构的本科生志愿者提供出海体验。

Downcore records of benthic foraminiferal shell composition can provide valuable records of deep water temperature and chemistry in the past. While field based calibration studies have defined the relationships between shell chemistry and bottom water conditions, our ability to interpret benthic foraminiferal proxy records continues to be challenged by the fact that multiple factors-- environmental and biological-- can influence most aspects of shell chemistry. Culture-based studies offer a promising complement to core-top calibrations, because in the laboratory it is possible to vary a single environmental variable while holding others constant. This research builds on previously funded culture work, here focusing on demonstrating calcification in culture, and reproduction and subsequent growth in culture, by Uvigerina and Cibicidoides species, two benthic foraminifera widely used in paleoceanography. Samples collected from the mid-Atlantic margin will be cultured under controlled and monitored physical and chemical conditions in order to assess the consistency of foraminiferal oxygen isotope values from the newly-formed shell material. The main focus is on foraminiferal growth and reproduction, which will lay important groundwork for future efforts toward proxy calibrations under variable environmental conditions. A female postdoctoral researcher will have a central role in the project. Other broader impacts include providing sea-going experience for undergraduate volunteers from non-oceanographic institutions.