Culturing Deep-sea Benthic Foraminifera - Multi-temperature Proxy Calibration, and Substrate and Food Experiments

确定海洋在气候和全球碳循环中的作用是了解自然气候变化工作的重要组成部分。对深海沉积物中保存的微观贝壳的化学分析提供了过去深海化学、循环和温度变化的关键记录。为了对这些基于微化石的古海洋学记录有信心，必须仔细校准贝壳化学对环境条件的反应。在本项目中，我们将利用多温度实验室培养对深海底栖有孔虫的壳氧同位素和Mg/Ca组成进行化学校准。实验将使用每年从大陆架和深海（500-2000米水深）地点收集的活底栖有孔虫。另外的实验将为最常用于古海洋学重建的深海底栖有孔虫类群建立最佳培养条件。本研究将为深海底栖有孔虫的氧同位素组成和镁钙比值这两个重要的深海“古温标”提供新的校准方法。我们基于文化的估算将为现场校准提供独特的独立测试，为重建深水温度提供基础。该项目的更广泛影响包括邀请来自非海洋学院和大学的本科生志愿者作为邮轮参与者，向他们介绍海上海洋学研究。

Determining the role of the ocean in climate and the global carbon cycle is an essential part of the effort to understand natural climate change. Chemical analyses of microscopic shells preserved in deep-sea sediments provide key records of changes in deep-water chemistry, circulation, and temperature in the past. To be confident in these microfossil-based paleoceanographic records, the shell-chemistry response to environmental conditions must be carefully calibrated. In this project, we will carry out chemistry calibrations of shell oxygen isotopic and Mg/Ca composition using multiple-temperature laboratory cultures of deep-sea benthic foraminifera. The experiments will use live benthic foraminifera collected each year from continental shelf and deep-sea (500-2000 m water depth) sites. Additional experiments will establish optimal culturing conditions for the deep-water benthic foraminiferal taxa most often used in paleoceanographic reconstructions. This study will provide new calibrations of two important deep water "paleothermometers" the oxygen isotopic composition and magnesium:calcium ratios of deep-sea benthic foraminifera. Our culture-based estimates will provide a unique independent test of the field-based calibrations that provide the foundation for reconstructions of deep-water temperature. The broader impacts of this project include inclusion of undergraduate volunteers from non-oceanographic colleges and universities as cruise participants, to introduce them to at-sea oceanographic research.