Quantification of sedimentary oxygen and carbon dioxide dynamics in a dry sandy beach affected by macroalgae deposition

受大型藻类沉积影响的干燥沙滩中沉积氧和二氧化碳动态的量化

• 批准号: 2049177
• 负责人: Markus Huettel
• 金额: $ 13.99万
• 依托单位: Florida State 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: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2049177&HistoricalAwards=false
• 关键词: Quantification; sedimentary; oxygen; carbon; dioxide

Sandy beaches provide habitat for endangered species, protect the coast, and are appreciated for their high social and economic values. They are facing escalating anthropogenic pressures through coastal development, nutrient increases and global warming, which in recent years led to the development of extensive seaweed blooms that deposit massive amounts of algae on sandy beaches worldwide. This project investigates the fate of the deposited algae and their influence on the biogeochemical environment of the beach.The decay of the algae locally depletes oxygen in the beach and produces toxic sulfides and high concentrations of ammonia that harm beach organisms, pollute nearshore waters and deter tourists. Research in this project quantifies biogeochemical and transport processes that control the algal decomposition. Generating these data is prerequisite for developing models that can predict the impact of the massive macroalgal deposition and thereby support decision making and coastal management. The project research is tightly linked to an educational component with instruction of graduate and undergraduate students in marine biogeochemical methods, and a dedicated outreach program informing the public about the seaweed issue and pathways to reduce this problem.The project produces data on the dynamics of oxygen and carbon dioxide distribution and interfacial gas flux in the dry, supralittoral zone (between high tide line and dunes) of sandy beaches and determines how distributions and fluxes are influenced by the degradation of the macroalgae. Organic carbon and nitrogen profiling characterizes the biogeochemical sedimentary environment at the two study sites, a carbonate and a silicate beach. A set of laboratory experiments relates gas fluxes to the degradation rate of buried macroalgal layers and the effects of gas exchange, temperature and moisture. The data will allow estimates of the time frame of the algal decomposition process and provide information on the degradation capacity of sandy beaches. Since beach sedimentary O2 and CO2 dynamics and fluxes are largely undescribed, the project data contribute to the mechanistic and quantitative understanding of carbon and nutrient cycling in sandy beaches.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.

桑迪为濒危物种提供栖息地，保护海岸，并因其高社会和经济价值而受到赞赏。由于沿海开发、营养物质增加和全球变暖，它们正面临着不断升级的人为压力，近年来导致海藻大量繁殖，在世界各地的桑迪上存款大量海藻。该项目调查沉积藻类的命运及其对海滩生物地球化学环境的影响，藻类的腐烂消耗了海滩局部的氧气，并产生有毒的硫化物和高浓度的氨，伤害海滩生物，污染近岸沃茨，阻止游客。该项目的研究量化了控制藻类分解的生物地球化学和运输过程。生成这些数据是开发模型的先决条件，这些模型可以预测大量大型藻类沉积的影响，从而支持决策和沿海管理。该项目的研究是紧密联系在一起的教育组成部分，指导研究生和本科生在海洋生物地球化学方法，和一个专门的推广计划，告知公众有关海藻问题和途径，以减少这一问题。该项目产生的数据动态的氧气和二氧化碳的分布和界面气体通量在干，这是一个关于桑迪的潮上带（高潮线和沙丘之间）的研究，并确定大型藻类的退化如何影响其分布和通量。有机碳和氮剖面表征了两个研究地点（碳酸盐和硅酸盐海滩）的地球化学沉积环境。一组实验室实验将气体通量与掩埋的大型藻类层的降解速率以及气体交换、温度和湿度的影响联系起来。这些数据将有助于估计藻类分解过程的时间范围，并提供关于桑迪退化能力的信息。由于海滩沉积的O2和CO2的动态和通量在很大程度上是未描述的，该项目的数据有助于碳和养分循环在桑迪的机械和定量的理解。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Drifter and dye tracks reveal dispersal processes that can affect phytoplankton distributions in shallow estuarine environments

漂流物和染料轨迹揭示了可能影响浅河口环境中浮游植物分布的扩散过程

• DOI: 10.1016/j.ecss.2022.107811
• 发表时间: 2022
• 期刊: Coastal and Shelf Science
• 作者: Geyer, Natalie L.;Balwada, Dhruv;Simons, Elizabeth;Speer, Kevin;Huettel, Markus
• 通讯作者: Huettel, Markus