Collaborative Research: In Situ Investigations and Historical Analysis of Eddy Impacts on coastal carbon chemistry and coral calcification

中尺度涡旋，通常被称为海洋的“天气”，是海洋中充满能量的循环洋流，它可以加强深层水域的上涌或表层水域的下涌。这反过来又会导致水化学和物理性质的变化，从而改变营养物质的可用性和初级生产速率、海洋表面pH值、温度和盐度。在中纬度的墨西哥湾流沿线，涡旋频率高，许多涡旋经过马尾藻海。虽然对涡旋物理及其对公海生物地球化学的影响进行了广泛的研究，但对涡旋对沿海生物地球化学的影响，特别是对浅层暖水珊瑚礁的影响的研究有限。由于人为变化，珊瑚礁面临着越来越大的压力，了解漩涡如何加剧或缓解这种压力变得越来越重要。在这个项目中，来自两个机构的三名研究人员将与他们的本科生和研究生一起调查中尺度漩涡对百慕大浅水珊瑚礁的影响，百慕大是一个位于马尾藻海中心的珊瑚礁包围岛屿。此外，从该提案中获得的技能和知识将通过STEM管道通过一系列针对高中学生和教师的教育计划以及两所机构的本科生研究机会转移。拟议的研究有三个具体目标，旨在提高目前对漩涡在珊瑚礁生物地球化学中所起作用的理解。(i)涡旋活动是否影响近岸水域的性质，包括温度、养分有效性和碳化学？（ii）海水性质的改变如何影响珊瑚钙化？（iii）能否在珊瑚骨架档案中追查已确定的海水变化，以追查过去的涡旋活动？这项研究将沿着边缘珊瑚礁研究地点进行海水剖面分析，与百慕大大西洋时间序列研究（BATS）和S站的类似时间剖面进行比较，以了解涡流驱动的变化如何从近海传播到岸上。将在百慕大南岸边缘珊瑚礁部署原位水采样器和传感器，研究海岸涡流对环境条件的影响，并利用孵化室研究这些条件如何影响珊瑚礁形成的主要过程，即珊瑚钙化。此外，将分析BATS和S站的历史数据，以确定高涡旋活动的年份，以调查这些年份BATS的物理条件和碳循环的变化，并将其与最近的珊瑚古化学记录进行比较，以确定过去重建的代理记录中的涡旋影响。该奖项反映了美国国家科学基金会的法定使命，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。

Mesoscale eddies, often referred to as the “weather” of the ocean, are energetic circulating currents in the ocean that can intensify upwelling of deeper waters or downwelling of surface waters. This in turn leads to changes in water chemistry and physical properties that can alter nutrient availability and rates of primary production, surface ocean pH, temperature, and salinity. Along the Gulf Stream in the mid-latitudes, eddy frequency is high with many transiting through the Sargasso Sea. While extensive research has been conducted on eddy physics and their impact on open-ocean biogeochemistry, there has been limited research on the impacts of eddies on coastal biogeochemistry, and, in particular, the effect of eddies on shallow warm-water coral reefs. Given the increasing stress coral reefs are facing due to anthropogenic changes, understanding how eddies may compound or relieve this stress is becoming increasingly important. In this project, three researchers from two institutions together with their undergraduate and graduate students will investigate the effect of mesoscale eddies on shallow water coral reefs in Bermuda, a coral reef surrounded island situated in the heart of the Sargasso Sea. Furthermore, the skills and knowledge gained from this proposal will be transferred through the STEM pipeline by a number of educational programs for high school students and teachers, and through undergraduate research opportunities at both institutions. The proposed research has three specific objectives that aim to improve current understanding of the role eddies play in reef biogeochemistry. (i) Does eddy activity affect water properties near shore, including temperature, nutrient availability, and carbon chemistry? (ii) How do the changes in water properties affect coral calcification? (iii) Can identified seawater changes be traced in coral skeleton archives to trace past eddy activity? This research will conduct sea water profiling along the rim reef study site to compare to similarly timed profiles at the Bermuda Atlantic Time-series Study (BATS) and Hydrostation S sites to understand how eddy driven changes propagate from offshore to onshore. In-situ water samplers and sensors will be deployed in Bermuda’s south shore rim reefs to study the impact of coastal eddies on the environmental conditions, and incubation chambers will be utilized to investigate how these conditions affect the primary process of reef formation, namely coral calcification. In addition, historical data from BATS and Hydrostation S occupations will be analyzed to identify years of high eddy activity to investigate changes to both the physical conditions and the carbon cycle at BATS in those years and compare them to recent records of coral paleo chemistry to identify eddy impacts in the proxy record for past reconstructions.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.