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

根据这一奖项，PIS将培养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保持，以确定环境和生理(“重要”)对底栖有孔虫壳层化学的影响。两个培养研究，每个大约需要一年的时间。这些都是为了解决控制底栖有孔虫贝壳化学的关键方面。每年都将培养来自220米水域的尖吻假单胞藻和来自深水水域的上底栖物种(例如，拟水母)。第一年的实验将通过调查碳酸盐离子浓度对贝壳成分(d13C、d18O、Cd、Ba、Mg、Sr、U、V)的影响，来追求迄今工作和以前浮游有孔虫培养研究的结果。第二年的实验将记录底栖有孔虫微量元素组成对溶解痕量金属浓度变化的响应，以及底栖有孔虫碳同位素组成对其藻类食物的d13C的响应。在这两年里，大量的培养工作(约25%的设施和时间)将用于探索性研究温度对有孔虫贝壳化学(特别是镁/钙)的影响，旨在帮助确定最适合未来培养工作的问题和方法。除了这些养殖研究外，还将进行现场有孔虫生命位置和贝壳组成的相关研究。该项目将使整个社会受益，因为结果将使人们能够更好地解释过去的气候变化。对过去气候变化的准确评估，对于对未来气候变化做出有信心的预测是必要的。这些预测反过来又为有关人为二氧化碳和其他温室气体排放的合理政策决策提供了必要的基础。

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.