MCA: Developing a Paleorecord of Hg in Long-Lived Mollusks from the Gulf of Maine

MCA：开发缅因湾长寿软体动物中汞的古记录

• 批准号: 2322048
• 负责人: Andrew Graham
• 金额: $ 23.73万
• 依托单位: Grinnell College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2322048&HistoricalAwards=false
• 关键词: MCA; Developing; Paleorecord; Hg; Long

Mercury (Hg) contamination is a serious environmental problem that affects ecosystems and human health, with most of human exposure coming from marine fish consumption. The impact of climate change and natural climate variability on the movement and bioaccumulation of Hg in marine ecosystems is not fully understood. Such understanding is vital to setting targets and assessing the progress of policy efforts to limit Hg contamination of marine ecosystems and human exposure. This research seeks to develop an approximately 1000-year record of Hg preserved in clam shells collected from the Gulf of Maine, one of the most rapidly warming regions of the world’s oceans. Like tree rings, clam shells possess layers that can be precisely dated and have potential to preserve highly resolved signals of past variation in Hg concentrations and accumulation by biota. Importantly, this Hg record can be paired with other kinds of climate proxy information preserved in the clam shells, giving detailed information about how marine Hg in this organism changes in response to a changing climate. This record will provide an especially useful dataset for calibrating and improving models for predicting the effects of policy and climate change on the recovery of marine ecosystems from centuries of Hg pollution. Other broader impacts include development of a new regional scientific partnership between researchers at a predominantly undergraduate institution (Grinnell College) and a large public research university (Iowa State University) and new opportunities for undergraduate research.Samples of the mollusk Arctica islandica will be collected from coastal locations in the Gulf of Maine and shell Hg concentrations compared to water, sediment, and biota concentrations of total Hg and methylmercury (MeHg). These comparisons will permit the researchers to evaluate whether shell Hg is a robust proxy of environmental Hg and MeHg bioaccumulation and to assess reproducibility of coeval shell samples. A master chronology of Hg in Gulf of Maine will then be constructed based on measuring shell Hg at high-resolution for an existing cross-dated A. islandica shell archive spanning the last millennium, a period which spans significant climatic and ocean circulation changes and large increases in Hg emissions from local and global sources. This record can be directly compared to existing and novel paleoclimate proxy records, including existing oxygen stable isotope records and newly measured trace-element records (Ba and Mn). Results of this work should permit determination of the sensitivity of Hg bioaccumulation to natural climate variability and evaluation of coupled biogeochemical-climate models used for predicting trajectory of future Hg in marine biota under various climate change scenarios. This project is jointly funded by the Division of Earth Sciences Geobiology and Low-Temperature Geochemistry Program, the Division of Ocean Sciences Marine Geology and Geophysics Program and the Established Program to Stimulate Competitive Research (EPSCoR).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.

汞（Hg）污染是一个严重的环境问题，影响生态系统和人类健康，其中大部分人类接触来自海洋鱼类消费。 气候变化和自然气候变异性对汞在海洋生态系统中的移动和生物累积的影响尚未得到充分了解。 这种理解对于设定目标和评估政策努力的进展至关重要，以限制海洋生态系统的汞污染和人类接触。 这项研究旨在建立一个大约1000年的记录，记录从缅因州海湾（世界海洋变暖最快的地区之一）收集的蛤蜊壳中保存的汞。 像树木年轮一样，蛤蜊壳也有可以精确测年的层，有可能保存过去生物群汞浓度和积累变化的高分辨率信号。 重要的是，这种汞记录可以与保存在蛤蜊壳中的其他类型的气候代用信息配对，提供关于这种生物体内海洋汞如何随着气候变化而变化的详细信息。 这一记录将提供一个特别有用的数据集，用于校准和改进模型，以预测政策和气候变化对海洋生态系统从数百年的汞污染中恢复的影响。 其他更广泛的影响包括在一个以本科为主的机构的研究人员之间建立新的区域科学伙伴关系（格林内尔学院）和一所大型公立研究型大学（爱荷华州州立大学）和本科生研究的新机会。将从缅因州的沿海地点收集软体动物Arctica islandica的样本，并将贝壳的汞浓度与水，沉积物，以及生物群中总汞和甲基汞的浓度。 这些比较将使研究人员能够评估贝壳汞是否是环境汞和甲基汞生物累积的可靠代表，并评估同时代贝壳样本的可重复性。 通过对缅因州湾现有的一个跨年A. islandica贝壳档案跨越了上个千年，这一时期气候和海洋环流发生了重大变化，当地和全球汞排放量大幅增加。 这一记录可以直接与现有的和新的古气候代用记录进行比较，包括现有的氧稳定同位素记录和新测量的微量元素记录（Ba和Mn）。 这项工作的结果将有助于确定汞生物累积对自然气候变化的敏感性，并评估用于预测各种气候变化情景下海洋生物群中汞未来轨迹的生物化学-气候耦合模型。 该项目由地球科学地球生物学和低温地球化学计划部、海洋科学海洋地质学和地球物理计划部以及刺激竞争性研究的既定计划（EPSCoR）共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。