Collaborative research: interdisciplinary approach to understand stable isotopic disequilibrium in benthic foraminifera

根据该奖项，专业人员将研究具有“极端”化学梯度的环境，这些梯度突出了生物碳酸盐与环境条件以及“正常”深海条件之间的化学差异。 极端的同位素梯度存在于冷甲烷渗漏提供了一个理想的栖息地，研究碳同位素不平衡（高达40 0/00）的影响，有孔虫方解石和溶解的无机碳（DIC）的环境水之间。最近的工作表明，生物因素（“生命效应”）和/或环境同位素组成影响有孔虫方解石的碳同位素特征。因此，拟议的工作将测试以下假设：1）底栖有孔虫集群在沉积物内的微生境; 2）食物类型影响有孔虫的碳同位素值; 3）共生体的存在是可变的物种内和物种之间，这种可变性反映在碳同位素特征。 这项工作应提供洞察力的重要问题是什么控制的碳同位素组成的底栖有孔虫测试（壳）？这个问题的答案将是至关重要的古环境重建渗漏和非渗漏环境。 这些资金还将用于社区外展（当地学校演示;网站开发）以及对本科生、研究生和博士后级别的几位未来科学家（包括代表性不足的群体）进行跨学科、实践培训。

Under this award the PIs will examine environments with "extreme" chemical gradients that accentuate chemical differences between biogenic carbonate and ambient conditions as well as those of "normal" deep-sea conditions. Extreme isotopic gradients present at cold methane seeps provide an ideal habitat to examine the effects of carbon isotopic disequilibrium (up to 40 0/00), between foraminiferal calcite and dissolved inorganic carbon (DIC) of ambient water. Recent work suggests that biological factors ("vital effects") and/or ambient isotopic compositions influence carbon isotopic signatures of foraminiferal calcite. Consequently, the proposed work will test the following hypotheses: 1) Infaunal foraminifera cluster in microhabitats within the sediments; 2) Food type influences foraminiferal carbon isotope values; 3) The presence of symbionts is variable within and between species, and this variability is reflected in carbon isotopic signatures. The work should provide insight to the important question of what controls the carbon isotopic composition of benthic foraminiferal tests (shells)? Answers to this question will be crucial for paleoenvironmental reconstructions in both seep and non-seep environments. The funds will also be used to include community outreach (local school presentations; web site development) and interdisciplinary, hands-on training of several future scientists at undergraduate, graduate, and post-doc levels, including under-represented groups.