Collaborative Research: Culturing Studies of Environmental Controls on Benthic Foraminiferal Shell Chemistry

根据该奖项，PI将培养能繁殖和钙化的有孔虫，并能在严格限制的碳酸盐化学和微量元素浓度下维持，以确定环境和生理（“重要”）对底栖有孔虫壳化学的影响。两个培养研究，将需要大约一年。 这些措施旨在解决控制底栖有孔虫壳化学的关键问题。在每一年，B。在220米的地点采集到的棘层动物和底栖物种（例如，Cibicidoides）从深水网站将培养。第一年的实验将通过调查碳酸根离子浓度对贝壳成分（d13 C、d18 O、Cd、Ba、Mg、Sr、U、V）的影响，来追求迄今为止的工作结果和以前对南极有孔虫的培养研究结果。第二年的实验将记录底栖有孔虫微量元素组成对溶解微量金属浓度变化的反应，以及底栖有孔虫碳同位素组成对其藻类食物d13 C的反应。大量的培养工作（约25%的设施和时间）将致力于在这两年的温度对有孔虫壳化学（特别是镁/钙）的影响进行探索性研究，旨在帮助确定最适合未来的文化工作的问题和方法。除了这些培养研究外，还将进行现场有孔虫生命位置和贝壳组成的相关实地研究。 该项目将使整个社会受益，因为其结果将有助于对过去气候变化进行更好的古海洋学解释。对过去气候变率的准确评估对于有信心地预测未来气候变化是必要的。这种预测反过来又为关于人为排放二氧化碳和其他温室气体的健全政策决定提供了重要基础。

AbstractUnder this award the PIs will culture foraminifera that reproduce and calcify and can be maintained under tightly constrained carbonate chemistry and trace element concentrations to determine environmental and physiological ("vital") influences on the shell chemistry of benthic foraminifera. Two culturing studies, will take about one year each. These are designed to address key aspects of the controls on benthic foraminiferal shell chemistry. In each year both B. aculeata from a 220-m site and also epibenthic species (e.g., Cibicidoides) from deeper-water sites will be cultured. Year 1 experiments will pursue results from work to date, and from previous culturing studies of planktic foraminifera, by investigating the influence of carbonate ion concentration on shell composition (d13C, d18O, Cd, Ba, Mg, Sr, U, V). Year 2 experiments will document the response of benthic foraminiferal trace element composition to variations in dissolved trace metal concentrations, and the response of benthic foraminiferal carbon isotopic composition to the d13C of their algal food. Substantial culturing effort (~25% of the facility and time) will be devoted in both years to exploratory studies on temperature influence on foraminiferal shell chemistry (in particular, Mg/Ca), designed to help define problems and approaches most suitable for future culture work. In addition to these culturing studies, related field-based studies of in situ foraminiferal life positions and shell composition will also be conducted. The project will benefit society at large because results will enable better paleoceanographic interpretations of past climate changes. Accurate assessments of past climate variability are necessary for confident predictions about future climate change. Such predictions, in turn, provide an essential foundation for sound policy decisions regarding anthropogenic release of CO2 and other greenhouse gases.