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: 2136377
• 负责人: Joan Bernhard
• 金额: $ 62.03万
• 依托单位: Woods Hole Oceanographic Institution
• 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=2136377&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.

岩溶地下河口（KSE）发生在世界各地，淡水和海洋衍生的沃茨在沿海含水层内混合，形成一个化学反应区，改变了输送到海洋的物质的组成，并维持了特有的水生生物群落。地球上大约四分之一的人口依赖岩溶（侵蚀石灰岩）供水，而在沿海地区，岩溶供水直接受到海平面上升、地下水开采失控和沿海地区快速发展的威胁。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仍然未知。虽然KSE中被淹没的洞穴的远洋成分已经研究了几十年，但这些洞穴和洞穴的活底栖（洞穴底部/海底宿主）动物群仍然研究不足。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淡水含水层和海洋环境之间的地下环境梯度的生态系统功能。被洪水淹没的沿海洞穴使团队能够进入KSE并进行直接观察。这项工作的成果有益于海洋底栖生态学和生物学、海洋地球化学、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跨国，多机构的合作，提高研究和奖学金的机会，在一个主要是本科西班牙裔服务机构在得克萨斯州和支持年轻的研究人员从代表性不足的群体在科学。为了推广，与该项目相关的博士生，谁是非洲裔美国女性，是共同撰写的半自传体儿童书籍关于洞穴潜水和洞穴相关生物的奇迹。 KSEs影响沿海碳和氮循环，因为它们缓冲了陆地物质输入和地下水排入海洋。虽然在KSE的淹没洞穴环境的远洋社区已经研究了几十年，由于他们的适应，地理学和进化的起源，生活底栖动物及其在KSE元素循环的作用仍然研究不足。该项目的总体目标是在尤卡坦半岛和科苏梅尔岛（墨西哥）被KSE淹没的广泛沿海洞穴中，建立跨环境梯度的底栖真核生物的多样性和生态，并确定它们如何与底栖元素循环相互作用。这项研究提供了一个整体表征KSE底栖生物使用跨学科领域和实验室为基础的方法，包括条形码/元条形码，元转录组学，超微结构分析，实验室培养，正在整合与生物地球化学和水文测量。具体而言，研究人员正在描述（1）相对于有机输入，跨越盐度/氧气梯度的沿海洞穴真核底栖生物群落空间生物多样性模式的驱动因素;（2）底栖小型底栖生物的作用（到纳米生物群）群落，重点是有孔虫，在生态系统功能中相对于介导有机物转化和氮循环的主导生物地球化学过程;以及（3）海底小型生物（到纳米生物）生物多样性和生态系统恢复力对与气象事件相关的季节性水文变化的时间限制。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。