Collaborative Research: A hydrological seesaw and its effect on alkalinity dynamics in estuaries along a climate gradient

合作研究：水文跷跷板及其对气候梯度河口碱度动态的影响

• 批准号: 2319434
• 负责人: Xinping Hu
• 金额: $ 56.97万
• 依托单位: Texas A&M University Corpus Christi
• 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=2319434&HistoricalAwards=false
• 关键词: Collaborative; Research; hydrological; seesaw; its

The main goal of this project is to learn how changes in freshwater conditions in shallow estuaries affect how much alkalinity, or acid-neutralizing capacity, the sediments produce or consume. It is hypothesized that a reduction in freshwater runoff will reduce alkalinity production in sediments via respirational processes that do not require oxygen; and during extreme drought, reduced compounds, for example reduced sulfur, produced from the above processes can be oxidized and generates acids. This project will examine three estuaries along the northwestern Gulf of Mexico with different amounts of freshwater inputs. One of the estuaries that experiences large freshwater runoff changes will be studied in more detail. The objective is to unravel the connection between these changes and the buildup and breakdown of reduced sulfur in the sediments. Additionally, the impact of these processes on the alkalinity of the water column will be assessed. This study will measure water column alkalinity changes and benthic fluxes, examine sedimentary record for historical changes, and conduct modeling to tie field measurements together. Researchers from both Texas A&M University-Corpus Christi (TAMU-CC) and Texas A&M University at Galveston (TAMUG) will work on this project. The team includes two early career scientists. Two graduate students, one from each campus, will use this project to develop their research. Results from this project will be used in classroom instructions as well as outreach activities. These activities include expanding the curriculum for an ongoing NSF National Research Traineeship program at TAMU-CC as well as developing a teaching module for Sea Camp at TAMUG, the latter serves elementary school students. It is known that electron acceptors other than dissolved oxygen can be used by microbes to respire organic carbon in nearshore sediments when the latter is absent. As a results, reduced sulfur is produced and preserved along with organic carbon preservation. However, the rate of this preservation is not constant and is subject to the amounts of nutrients and terrestrial organic carbon that rivers deliver. The results of this study will shed light on the role of hydrological conditions in nearshore alkalinity production and consumption. The findings will also be applied to other coastal regions in the face of decline in freshwater runoff. In addition, the model developed in this project can be used in a wide variety of applications in coastal research and management.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.

该项目的主要目标是了解浅河口中淡水条件的变化如何影响沉积物产生或消耗的碱度或酸中和酸的能力。假设淡水径流的减少将通过不需要氧气的呼吸过程减少沉积物中的碱度产量。在极端干旱期间，从上述过程产生的还原化合物（例如减少的硫）可以被氧化并产生酸。该项目将检查墨西哥西北湾的三个河口，并使用不同量的淡水投入。将更详细地研究经历大型淡水径流变化的河口之一。目的是揭示这些变化与沉积物减少的硫的堆积和分解之间的联系。此外，将评估这些过程对水柱碱度的影响。这项研究将测量水柱的碱度变化和底栖通量，检查历史变化的沉积记录，并进行建模以将现场测量结合在一起。来自德克萨斯州A＆M大学 - 科尔普斯·克里斯蒂（Tamu-CC）和德克萨斯A＆M大学的研究人员将在该项目上工作。该团队包括两个早期的职业科学家。两个研究生，一个来自每个校园的研究生将使用该项目来发展他们的研究。该项目的结果将用于课堂说明以及外展活动。这些活动包括扩大塔姆CC中正在进行的NSF国家研究训练计划的课程，以及为Tamug的海营教学模块开发教学模块，后者为小学生提供服务。 众所周知，除溶解氧气以外的其他电子受体可以被微生物使用时在近岸沉积物中呼吸有机碳，而后者不存在。结果，与有机碳保存一起产生并保存硫的减少。但是，这种保存的速度并不恒定，并且受河流提供的养分和陆生有机碳的量。这项研究的结果将阐明水文条件在近海碱度生产和消费中的作用。面对淡水径流的下降，这些发现还将应用于其他沿海地区。此外，该项目中开发的模型可用于沿海研究和管理中的各种应用中。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知识分子优点和更广泛影响的评估标准通过评估来支持的。