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: 2202879
• 负责人: Eileen Hofmann
• 金额: $ 9.55万
• 依托单位: Old Dominion University Research Foundation
• 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=2202879&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.

重建大陆架双壳类底层水温：全新世历史是大西洋中部未来的窗口美国东海岸附近的大西洋中部大陆架海水正在迅速变暖。这些大陆架水域有一个独特的特征，即冷水池，它是在夏季表层海水变暖而将冬季寒冷的水困在底部时形成的。 冷水池面积很大，但随着大陆架海水变暖，其覆盖面积预计会缩小。冷水池是两种底栖蛤类——圆蛤和大西洋蛤的栖息地。这些动物，尤其是海洋圆蛤，寿命很长。 蛤的生长和经历的温度记录都保存在它们的壳中，类似于树木的年轮。 冷池中的活蛤和化石蛤的壳将被用来估计过去约 5000 年的底层水温。 底部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非常重要。 蛤壳的底部水温将显示蛤的分布如何因气候变暖而变化。分布的变化很重要，因为可能对蛤渔业产生经济影响。培训本科生和研究生将是该项目的一部分，并将促进海洋学和古气候科学之间的联系。针对 K-8 学生的教育外展计划以及通过艺术联盟 RI 组织的 Synergy 项目开展的与科学相关的艺术倡议将突出通过询问蛤来揭示海底水温变化的新颖方法。 大西洋中部大陆架气候变化的历史是由两种长寿双壳类动物——大西洋北蛤（Spisula Solidissima）和海洋圆蛤（Arctica islandica）的贝壳记录的。随着这些蛤的生长，壳会分层沉积。对沿着贝壳生长轴的碳 (C12/C14) 和氧 (O16/O18) 同位素比率进行分析，可以了解生长中的蛤在数百至数千年前所经历的温度，以及其随季节变化的情况。化石贝壳的堆积被称为死亡组合。从活贝壳和化石贝壳中获得的温度时间序列将用于开发过去约 5000 年中大西洋陆架底部水温的时空重建。每年夏天，当分层将寒冷的冬季水沿着陆架底部困在一层较温暖的水下方时，就会形成一个冷水池。将特别注意该冷池的变化。 了解大陆架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，这些变化对两种蛤类物种持续范围变化的影响，并可以预测未来的范围分布。 对重建的底层水温的分析将确定自新冰期开始以来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快速度。 与范围变化相关的潜在气候驱动因素将根据重建的底层水温度并与其他北大西洋重建进行比较来确定。将评估底层水温变化对蛤死亡事件发生时间的影响。重建的底层水温记录将扩展回顾性模型的输入，并与中大西洋地区不断变化的物种分布（来自收集地点记录）相关。反过来，这些重建为未来预测提供了基础，并对持续变暖对生态过程和渔业生产的影响进行预测。这项工作汇集了具有广泛专业知识的科学家，特别是包括作为主要研究人员的年轻研究人员以及研究生和本科生。该奖项反映了 NSF 的法定使命，并通过使用基金会的评估进行评估，被认为值得支持。智力价值和更广泛的影响审查标准。