CAREER: Quantifying Western Atlantic Climate and Seasonality across the Plio-Pleistocene Regional Molluscan Extinction

职业：量化上皮奥-更新世区域性软体动物灭绝过程中的西大西洋气候和季节性

• 批准号: 2237429
• 负责人: Sierra Petersen
• 金额: $ 79.86万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2028-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2237429&HistoricalAwards=false
• 关键词: CAREER; Quantifying; Western; Atlantic; Climate

Over the past ~4 million years, 70-80% of mollusk species (clams, scallops, etc.) living in the waters of the Atlantic & Gulf Coasts have disappeared. New species originated to replace those that went extinct, and the mollusk population remains quite diverse today. The cause of this great turnover in species has not been established. The primary hypothesis is that declining water temperatures pushed out warm-water-loving species and replaced them with those that could inhabit cooler waters. The researcher will produce robust, quantitative temperature estimates from sites up and down the East Coast over the past 3-5 million years and compare those to extinction patterns of marine mollusks to test this hypothesis. In addition to addressing the root cause of the extinction, these data will reveal information about the thermal tolerances of studied mollusk species and determine whether those are fixed or flexible (meaning a species could adapt to live in different water temperatures than it currently inhabits). This will have implications for the survival of mollusks living in American waters (including those farmed for aquaculture like clams and scallops) in the coming decades and centuries as ocean temperatures warm. The researcher will share their findings with the public through a number of outreach projects and exhibits in partnership with the UMich Museum of Natural History. They will create an authentic research experience course to introduce more undergraduates to research in a way that lowers barriers-to-entry, especially for underrepresented groups. The researcher will conduct a program of isotopic measurements on fossil mollusks using the clumped isotope paleothermometer (D47), including calibrations of modern marine gastropods and bivalves. Use of this new method is vital, as preliminary D47-based temperature estimates differ greatly from historical oxygen-isotope-based estimates which are flawed due to their poor constraints on past oxygen isotopic composition of seawater (d18Osw). Data generated here will directly address questions of niche stability in mollusk taxa through determination of changes (or lack thereof) in thermal tolerances over time and space.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在过去的约400万年中，生活在大西洋和墨西哥湾沿岸水域中的70-80％的软体动物（蛤，扇贝等）消失了。新物种起源于取代灭绝的物种，如今软体动物的种群仍然非常多样化。尚未建立这种巨大营业额的原因。主要的假设是，下降的水温将热爱水的物种推出，并将其替换为可以居住在凉爽水域的物种。研究人员将在过去的3 - 500万年中从东海岸上下产生稳健的定量温度估计，并将这些温度估计与海洋软体动物的灭绝模式进行比较，以检验这一假设。除了解决灭绝的根本原因外，这些数据还将揭示有关软体动物物种的热耐受性的信息，并确定它们是固定还是柔性的（这意味着物种可以适应与当前居住的水温度不同）。这将对居住在美国水域中的软体动物的生存产生影响，包括在接下来的几十年中，随着海洋温度的温暖，在未来几十年和几个世纪以来，在美国水域（包括蛤lam和扇贝）的生存。研究人员将通过与乌米希自然历史博物馆合作通过许多外展项目和展览与公众分享他们的发现。他们将创建一个真实的研究经验课程，以降低进入障碍的方式介绍更多的大学生，以降低障碍，尤其是对于代表性不足的群体。研究人员将使用汇总的同位素层计（D47）对化石软体动物进行一项同位素测量程序，包括现代海洋局部胃足和生物体的校准。这种新方法的使用至关重要，因为基于D47的初步温度估计与基于历史氧相关的历史估计值大不相同，这些估计因其对过去的海水的氧气同位素组成的限制不佳而存在缺陷（D18OSW）。此处生成的数据将通过确定随时间和空间的热公差的变化（或缺乏）的变化来直接解决Mollusk分类单元中的利基稳定性问题。该奖项反映了NSF的法定任务，并被认为值得通过基金会的知识分子优点和更广泛的影响来通过评估来获得支持。