Collaborative Research: Reconstructing bottom water temperatures from bivalves on the continental shelf: Holocene history as a window to the future in the Mid-Atlantic

合作研究：重建大陆架双壳类底层水温：全新世历史是大西洋中部未来的窗口

• 批准号: 2202903
• 负责人: Eric Powell
• 金额: $ 10.35万
• 依托单位: University of Southern Mississippi
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2202903&HistoricalAwards=false
• 关键词: Collaborative; Research; Reconstructing; bottom; water

Reconstructing bottom water temperatures from bivalves on the continental shelf: Holocene history as a window to the future in the Mid-AtlanticThe ocean waters of the Middle Atlantic continental shelf off the east coast of the United States are warming rapidly. These continental shelf waters have a unique feature, the cold pool, that is formed when summer warming of surface waters traps cold winter water along the bottom. The cold pool is extensive but the area it covers is expected to shrink as shelf waters warm. The cold pool is home to two bottom dwelling clam species, ocean quahogs and Atlantic surfclams. These animals, especially ocean quahogs, are long lived. Records of growth and the temperature the clams experienced are preserved in their shells, similar to tree rings. The shells of live and fossil clams from the cold pool will be used to estimate bottom water temperature over the past ~5000 years. The bottom temperatures will be linked to past climate periods and known climate variability that influence the Middle Atlantic. Understanding cold pool changes is important for studying past climate change and projecting future changes for the Middle Atlantic region. The bottom water temperatures from the clam shells will show how clam distributions might change in response to climate warming. Changes in distribution are important because of possible economic impacts on the clam fishery. Training undergraduate and graduate students will be part of this project and will foster linkages between oceanography and paleoclimate science. Educational outreach programs for K-8 students and a science-related art initiative through the Synergy project organized by Art League RI will highlight the novel approach of asking clams to reveal changes in ocean bottom water temperature. The history of climate change on the Middle Atlantic continental shelf is recorded by the shells of two long-lived bivalves, the Atlantic surfclam, Spisula solidissima, and the ocean quahog, Arctica islandica. Shell is deposited in layers as these clams grow. Analysis of the ratios of carbon (C12/C14) and oxygen (O16/O18) isotopes along the growth axes of the shell indicates the temperatures that were encountered by the growing clam hundreds to thousands of years ago, and also how this varied seasonally. The accumulation of fossil shells is termed a death assemblage. The temperature time series obtained from the living and fossil shells will be used to develop spatial-temporal reconstructions of bottom water temperatures on the Middle Atlantic shelf for the past ~5000 years. A cold pool of water forms each summer when stratification traps cold winter water along the shelf bottom below a layer of warmer water. Particular attention will be paid to variability in this cold pool. Understanding the history of climate change on the continental shelf will provide important information on past climatic changes in this region, the impact of these changes on ongoing range shifts of the two clam species, and allow projection of future range distributions. Analyses of the reconstructed bottom water temperatures will determine the historical frequency and, where possible, rapidity of major climatic changes and corresponding range shifts since the beginning of the Neoglacial Period. Potential climate drivers associated with the range changes will be determined from the reconstructed bottom-water temperatures and compared with other North Atlantic reconstructions. The influence of bottom water temperature changes on the timing of clam mortality events will be assessed. The reconstructed bottom water temperature records will extend inputs for retrospective models and be related to changing species distributions (from collection location records) in the Middle Atlantic region. In turn these reconstructions provide the basis for forward projections with implications for continued warming on ecological processes and fishery production. This effort brings together scientists with a broad range of expertise, and notably includes both young investigators as lead investigators, and students at both the graduate and undergraduate level.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.

重建大陆架上的双壳类动物的底部水温：全新世历史作为通往未来中大西洋中部大西洋大陆货架中的未来的窗口，在美国东海岸附近的海水正在迅速变暖。这些大陆架子水具有独特的特征，即冷池，当地表水的夏季变暖沿底部捕获寒冷的冬季水时形成。 冷池很广泛，但预计随着架子水的温暖，预计将收缩。冷池是两个底部居住的蛤种类，海洋Quahogs和大西洋冲浪板的所在地。这些动物，尤其是海洋Quahogs，长期以来一直存在。 生长记录和蛤所经历的温度被保存在壳中，类似于树环。 在过去〜5000年中，从冷池的活蛤和化石蛤s壳将用于估计底部水温。 最低温度将与过去的气候时期和影响中大西洋的已知气候变化有关。 了解冷池变化对于研究过去的气候变化和预测中大西洋地区的未来变化很重要。 蛤壳的底部水温将显示蛤分布如何随着气候变暖而变化。分布变化很重要，因为可能对蛤渔业产生经济影响。培训本科生和研究生将成为该项目的一部分，并将建立海洋学与古气候科学之间的联系。针对K-8学生的教育外展计划和通过Art League RI组织的协同项目的与科学相关的艺术计划将强调新颖的方法，即要求蛤lam揭示海洋底部水温的变化。 两个长寿命的双壳类人，大西洋冲浪板，Spisula Solidissima和Acear Quahog，Arctica Islandica的贝壳记录了中大西洋大陆架子上的气候变化历史。随着这些蛤的生长，壳会沉积在层中。分析碳（C12/C14）和氧气（O16/O18）沿壳的生长轴的比率，这表明数百至数千年前遇到的温度遇到的温度以及季节性如何变化。化石壳的积累称为死亡组合。从生活和化石壳获得的温度时间序列将用于在过去〜5000年中开发中大西洋架子上底部水温的时空重建。每年夏天，当分层捕获沿着温暖的水层下方的架子底部捕获冷冬水时，一个冷水池形成。特别关注此冷池的可变性。 了解大陆货架上气候变化的历史将提供有关该地区过去气候变化的重要信息，这些变化对两个蛤lam物种的持续范围变化的影响，并允许对未来范围分布的预测。 对重建的底部水温的分析将决定自新冰期开始以来的主要气候变化和相应范围变化的历史频率，并在可能的情况下确定。 与范围变化相关的潜在气候驱动因素将取决于重建的底水温，并与其他北大西洋重建相比。底部水温变化对蛤死亡事件时机时机的影响将被评估。重建的底部水温记录将扩展回顾性模型的输入，并与中大西洋地区的不断变化的物种分布（从收集位置记录）有关。反过来，这些重建为远期预测提供了基础，对持续对生态过程和渔业生产的持续变暖产生了影响。这项努力将科学家汇集了广泛的专业知识，特别是包括年轻的研究人员作为主要研究人员和研究生和本科级别的学生。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的评估来支持的。智力优点和更广泛的影响审查标准。