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理解自然气候变化努力的重要组成部分。对保存在深海沉积物中的微观贝壳进行的化学分析提供了过去深水化学、环流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，必须仔细校准贝壳对环境条件的反应。在这个项目中，我们将利用深海底栖有孔虫的多温度实验室培养物进行贝壳氧同位素和镁/钙组成的化学标定。这些实验将使用每年从大陆架和深海(500-2000米水深)地点收集的活的底栖有孔虫。其他实验将为最常用于古海洋重建的深水底栖有孔虫类群确定最佳的养殖条件。这项研究将为深海底栖有孔虫的氧同位素组成和镁钙比这两个重要的深水“古温度计”提供新的刻度。我们基于培养的估计将为现场校准提供一种独特的独立测试，为重建深水温度奠定基础。该项目的更广泛影响包括将来自非海洋学院和大学的本科生志愿者纳入邮轮参与者，向他们介绍海上海洋研究。

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.