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

从大陆架上的双壳类重建底层水温：全新世历史作为中大西洋未来的窗口美国东海岸外中大西洋大陆架的海洋沃茨正在迅速变暖。这些大陆架沃茨有一个独特的特征，即冷池，这是当夏季表层沃茨变暖时形成的，冬季寒冷的水沿着底部。 冷池很大，但随着大陆架沃茨变暖，它所覆盖的面积预计会缩小。冷池是两种底栖蛤蜊物种的家园，海洋quahogs和大西洋surfclams。这些动物，特别是海洋quahogs，寿命很长。 蛤的生长和温度记录保存在它们的壳中，类似于树木的年轮。 冷池中的活蛤和化石蛤的壳将用于估计过去~5000年的底层水温。 海底温度将与过去的气候时期和影响大西洋中部的已知气候变化有关。 了解冷池的变化对于研究中大西洋地区过去的气候变化和预测未来的变化非常重要。 来自蛤蜊壳的底部水温将显示蛤蜊的分布可能会因气候变暖而发生变化。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，并将促进海洋学与古气候科学之间的联系。针对K-8学生的教育推广计划和通过Art League RI组织的协同项目开展的与科学相关的艺术倡议将突出要求蛤蜊揭示海底水温变化的新颖方法。 中大西洋大陆架气候变化的历史由两种长寿的双壳贝类--大西洋冲浪蛤（Spisula solidissima）和海洋方蛤（Arctica islandica）的贝壳记录。这些蛤蜊生长时壳会一层一层地沉积下来。沿着贝壳生长轴的碳（C12/C14）和氧（O 16/O 18）同位素比率的分析表明了数百至数千年前生长的蛤蜊所遇到的温度，以及这种温度如何随季节变化。贝壳化石的堆积被称为死亡组合。从活的和化石贝壳获得的温度时间序列将被用来开发的时空重建的底层水温在中大西洋大陆架在过去的5000年。每年夏天，当层化作用将冬季的冷水沿着陆架底部截留在温暖的水层下面时，就会形成一个冷水池。将特别注意这个冷池的变化。 了解大陆架气候变化的历史，将提供重要的信息，过去的气候变化，在这个地区，这些变化的影响，正在进行的范围转移的两个蛤类，并允许预测未来的范围分布。 对重建的底层水温的分析将确定历史频率，并在可能的情况下，确定自新冰期开始以来主要气候变化和相应范围变化的速度。 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确定，并与北大西洋其他重建进行比较。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输入的回顾性模型，并与不断变化的物种分布（从收集位置记录）在中大西洋地区。反过来，这些重建提供的基础上，对生态过程和渔业生产的持续变暖的影响进行前瞻性预测。这项工作汇集了具有广泛专业知识的科学家，特别是包括作为首席研究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，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

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.