Collaborative Research: Illuminating Cave Benthos in Subterranean Estuaries- Biodiversity, Ecology, and Role in Coastal Ecosystem Functioning

合作研究：阐明地下河口的洞穴底栖动物——生物多样性、生态学以及在沿海生态系统功能中的作用

• 批准号: 2136322
• 负责人: Elizabeth Borda
• 金额: $ 31.75万
• 依托单位: Texas A&M University-San Antonio
• 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: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2136322&HistoricalAwards=false
• 关键词: Collaborative; Research; Illuminating; Cave; Benthos

Karst subterranean estuaries (KSEs) occur worldwide where fresh and marine-derived waters mix within coastal aquifers, creating a chemical reaction zone that alters the composition of materials transported to the sea and sustains characteristic aquatic communities. Approximately one quarter of Earth’s population depends on karst (eroded limestone) water supplies that – within coastal regions – are directly threatened by rising sea level, uncontrolled groundwater extraction, and rapid coastal development. Yet, the role of these ecosystems in coastal biogeochemical cycling and groundwater health remains unknown. While pelagic constituents of flooded caves in KSEs have been studied for decades, the living benthic (cave floor / seafloor-hosted) fauna of these caves and caverns remains understudied. The overarching goal of this project is to better understand how benthic biodiversity affects ecosystem functioning across subsurface environmental gradients between freshwater aquifers and the marine environment. Flooded coastal caves allow the team to access the KSEs and make direct observations. Results of this work benefit marine benthic ecology and biology, biogeochemistry, paleoecology and biodiversity assessments. This interdisciplinary project establishes a multinational, multi-institutional collaboration, enhance research and scholarship opportunities at a predominantly undergraduate Hispanic-serving institution in Texas and support young investigators from under-represented groups in the sciences. For outreach, the project-associated PhD student, who is an African American female, is co-authoring a semi-autobiographical children’s book about cave diving and the wonders of cave-associated organisms. KSEs influence coastal carbon and nitrogen cycling because they buffer terrestrial material inputs with groundwater discharge into the oceans. While pelagic communities of flooded cave environments in KSEs have been studied for decades due to their adaptations, biogeography, and evolutionary origin, the living benthic fauna and their role in KSE elemental cycling remains understudied. The overall aim of this project is to establish the diversity and ecology of benthic eukaryotes across environmental gradients in extensive coastal caves flooded by the KSE in the Yucatan Peninsula and Cozumel Island (Mexico) and determine how they interact with benthic elemental cycles. This study provides a holistic characterization of KSE benthos using interdisciplinary field- and lab-based approaches including barcoding/meta-barcoding, meta-transcriptomics, ultrastructural analysis, and lab culturing that are being integrated with biogeochemical and hydrological measurements. Specifically, the investigators are characterizing (1) the drivers of spatial biodiversity patterns in coastal cave eukaryotic benthic communities across salinity/oxygen gradients, relative to organic inputs; (2) the role of benthic meiofauna (to nanobiota) communities, with emphasis on foraminifera, in ecosystem function relative to dominant biogeochemical processes that mediate organic matter transformations and nitrogen cycling; and (3) the temporal constraints of benthic meiofauna (to nanobiota) biodiversity and ecosystem resilience in response to seasonal hydrological variation associated with meteorological events.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.

喀斯特地下河口（KSE）发生在全球范围内，在沿海含水层内新鲜和海洋衍生的水混合，创建了一个化学反应区，从而改变了运送到海洋的材料的成分，并自杀了。地球人口大约四分之一的人口取决于喀斯特（侵蚀的石灰石）供水，这些供水在沿海地区内部直接受到海平面上升，不受控制的地下水提取和快速沿海开发的威胁。然而，这些生态系统在沿海生物地球化学循环和地下水健康中的作用尚不清楚。虽然数十年来，尽管KSES中泛滥成灾洞穴，但这些洞穴和洞穴的生物底栖动物（洞穴地板 /海底托管）动物区系仍被了解。该项目的总体目标是更好地了解底栖生物多样性如何影响泛滥的沿海洞穴之间的地下环境梯度的生态系统功能，使团队能够访问KSES并直接观察。这项工作的结果受益于海洋底栖生态学和生物学，生物地球化学，古生态学和生物多样性评估。这个跨学科的项目建立了一个多机构的多机构合作，在德克萨斯州的一个主要是本科的西班牙裔美国人服务机构中增强了研究和奖学金机会，并支持科学中代表性不足的群体的年轻调查员。对于外展活动，与非裔美国人相关的项目相关博士学位学生正在共同撰写一本关于洞穴潜水和洞穴相关生物奇观的半自传儿童读物。 KSE会影响沿海碳和氮气循环，因为它们可以缓冲地下水排放到海洋的陆地材料输入。尽管由于其适应性，生物地理和进化起源，KSES中洪水泛滥的环境的上层群落已经研究了数十年，但活着的底栖动物群及其在KSE元素循环中的作用仍然被了解。该项目的总体目的是建立在尤卡坦半岛和科苏梅尔岛（墨西哥）淹没的广泛沿海洞穴中底栖真核生物的多样性和生态，并确定它们与底栖元素的相互作用。这项研究使用跨学科田间和基于实验室的方法对KSE底栖生物进行了整体表征，包括条形码/元编码，荟萃分析，超微结构分析和实验室培养，这些方法与生物地球化学和氢的测量集成在一起。具体而言，研究人员正在表征（1）相对于有机输入，跨盐度/氧梯度的沿海洞穴真核生物底栖群落中空间生物多样性模式的驱动因素； （2）底栖动物（对纳米群）群落的作用，重点是有孔虫，在生态系统功能相对于主导的生物地球化学过程，介导有机物转化和氮气循环； （3）底栖动物（对纳米群）生物多样性和生态系统适应力的暂时限制，以应对与气象事件相关的季节性水文变异的响应。该奖项反映了NSF的法定任务，并通过基金会的知识优点和广泛的criperia来诚实地通过评估来进行评估，以诚实地通过评估来进行评估。