Collaborative Research: Biologically-driven island-building during sea-level rise and its implications for promoting resilient coastlines

合作研究：海平面上升期间生物驱动的岛屿建设及其对促进海岸线恢复力的影响

• 批准号: 2032130
• 负责人: Maya Gomes
• 金额: $ 12.02万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2032130&HistoricalAwards=false
• 关键词: Collaborative; Research; Biologically; driven; island

Coastal regions are at high risk for flooding and erosion due to climate change. Mangroves help protect coastlines by trapping small sediment called mud. The accumulation of mud layers counteracts sea-level rise. This project will examine sediment trapping by microbial mats, layered communities of microorganisms. Microbial mats are common in mangrove ecosystems and previous research has shown that microbial mats can trap larger sediment than mangroves. The PIs hypothesize that microbial mats may be playing an important but under-appreciated role in trapping sand-sized sediment. This will be tested using field observations and modeling to understand whether microbial mats helped build emergent land in three study sites. Results will be used to evaluate whether it is useful to consider microbial mats in coastal management practices more broadly. A short educational film featuring the key conclusions of this project will be shared with local communities and the broader public. This project will also provide training to high school and graduate students.The PIs will test the hypothesis that microbial mats can augment grain-trapping effects of mangroves, resulting in the accumulation and early cementation of coarse sediment that makes coasts resilient to sea-level rise and increased hurricane intensities. The primary study site is Little Ambergris Cay (LAC), an uninhabited island in the Turks and Caicos Islands that accreted over approximately the last 10,000 years, characterized by thick microbial mats, carbonate-cemented hardgrounds, and mangrove thickets with underlying sediment dominantly composed of ooids, carbonate sand grains that form via precipitation from seawater. The project will apply a multidisciplinary approach to examine how biology contributed to the construction of emergent topography during sea-level rise and evaluate how the processes involved could be applied to enhance coastal resiliency in other areas. The project will consist of four components: (1) real-time observations of rates and mechanisms of sediment stabilization by microbial mats; (2) analysis of a 10,000 year, Holocene, depositional record to assess rates and spatial variations in sediment accumulation; (3) sediment transport modeling to reconstruct island development to test whether local hydrodynamics and inorganic cementation are sufficient to create the emergent topography observed or, alternately, if biological influence is required; and (4) comparing LAC microbial community and sediment accumulation patterns with two contrasting coastal systems (one in the Florida Keys and one in Belize) to identify how the unique ecology of LAC relates to other coastlines. In addition to evaluating whether the interactions of microbial mats with mangroves and sediment transport dynamics affect sediment accumulation in coastal regions at risk from rising sea-level, this project will also contribute to understanding of the diversity, activity, and morphology of mangrove-associated microbial communities.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.

由于气候变化，沿海地区面临洪水和侵蚀的高风险。红树林通过捕获称为泥土的小沉积物来帮助保护海岸线。泥层的积累抵消了海平面的上升。该项目将检查微生物垫，分层微生物群落的沉积物诱捕。微生物垫在红树林生态系统中很常见，先前的研究表明，微生物垫可以捕获比红树林更大的沉积物。 PI假设微生物垫在捕获砂粒沉积物中起着重要但被低估的作用。将使用现场观测和建模对此进行测试，以了解微生物垫是否有助于在三个研究地点建造新兴的土地。结果将用于评估在沿海管理实践中考虑微生物垫是否有用。一部简短的教育电影以该项目的关键结论与当地社区和更广泛的公众共享。该项目还将为高中和研究生提供培训。PIS将检验以下假设：微生物垫可以增强红树林的谷物捕捞影响，从而导致粗泥浆的积累和早期胶结，使海岸得到沿海平面升高的升高并增加了飓风强度。主要的研究地点是Little Ambergris Cay（LAC），这是土耳其人和凯科斯群岛中的一个无人居住的岛屿，在过去的10，000年中积聚了，其特征是厚实的微生物垫，碳酸盐粘附的硬地面和红树林灌木丛，其潜在的沉积物主要由占主导地位的沉积物组成。 Ooids，通过海水沉淀形成的碳酸盐沙粒。该项目将采用多学科的方法来研究生物学在海平面上升期间如何贡献新兴地形的构建，并评估如何应用所涉及的过程来提高其他领域的沿海弹性。该项目将由四个组成部分组成：（1）通过微生物垫的实时观察速率和沉积物稳定机制； （2）分析10,000年，全新世，沉积记录，以评估沉积物积累的速率和空间变化； （3）沉积物运输建模以重建岛屿的发展，以测试局部流体动力学和无机胶结是否足以创建观察到的新兴地形，或者，如果需要生物学影响，则交替地创建； （4）将LAC微生物群落和沉积物的积累模式与两个对比的沿海系统（一个在佛罗里达钥匙中，一个在伯利兹）进行比较，以确定LAC的独特生态与其他海岸线的关系。除了评估微生物垫与红树林和沉积物传输动态的相互作用是否会影响海平面上升风险的沿海地区的沉积物积累，该项目还将有助于理解红树林相关微生物的多样性，活动和形态社区。该奖项反映了NSF的法定使命，并通过使用基金会的知识分子优点和更广泛的影响审查标准来评估值得支持。