Collaborative Research: Reevaluating calcification response to changes in seawater chemistry by testing the Proton Flux Hypothesis and the Coral Metabolism Model

珊瑚建造碳酸钙骨架以维持珊瑚礁的三维结构，珊瑚礁为许多生物提供栖息地，并保护海岸线免受生物侵蚀和风暴破坏。然而，海洋化学的变化威胁到珊瑚建造和维持这些重要生态结构的能力。为了进一步了解气候变化如何影响珊瑚礁，该项目调查了海洋碳酸盐化学变化如何直接影响珊瑚钙化。研究人员正在对生长在海水水箱中的珊瑚进行一系列实验，以研究珊瑚在不断变化的海洋中对海水化学的反应。该项目的更广泛影响包括学生研究机会、科学探究实验室和虚拟学习。该项目支持对化学、工程和海洋生态学科的几名早期职业研究人员、博士生、本科生和高中生的培训。研究人员与德克萨斯州水族馆合作，通过一系列关注珊瑚礁健康的虚拟研究探险与公众交流。这个系列包括采访，幕后参观，以及在夏威夷珊瑚礁上的虚拟潜水。这个项目通过调查珊瑚周围微环境中海水化学的调节来研究海水化学和珊瑚生理学之间的基本联系。具体地说，该项目1)研究了珊瑚对不同碳酸盐化学的响应，2)描述了不同海洋酸化条件下珊瑚边界层的质子梯度。这项工作的结果隔离了碳酸盐离子或氢离子对钙化率有更大的影响。这项工作利用了一种最先进的实验中温带设备，该设备结合了一个自动化系统，可以同时和独立地控制水箱中的总碱度和二氧化碳，以检查不同碳化学情景下珊瑚的反应。珊瑚周围的小尺度碳化学梯度正在使用一种创新的固态、无试剂传感器进行表征，该传感器能够同时测量两个关键的碳系统参数。珊瑚生物响应变量在短期孵化和长期中观操作期间被量化，以了解跨多个尺度(即，个人和社区尺度)和跨界层的生理影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Corals build calcium carbonate skeletons to maintain the three-dimensional structure of a coral reef, which provides habitat for many organisms and protects shorelines from bioerosion and storm damage. However, changes in ocean chemistry threaten the ability of corals to build and sustain these ecological important structures. To further the understanding of how climate change impacts coral reefs, this project investigates how changes in ocean carbonate chemistry directly influence coral calcification. The researchers are conducting a series of experiments on corals grown in seawater tanks to study corals responses to seawater chemistry in a changing ocean. Broader impacts of the project include student research opportunities, science-inquiry labs, and virtual learning. This project supports the training of several early career researchers, Ph.D. students, undergraduates, and high school students in the disciplines of chemistry, engineering, and marine ecology. Researchers partner with the Texas State Aquarium to communicate with the general public through a virtual research expedition series that will focus on coral reef health. This series includes interviews, behind the scene tours, and virtual dives on coral reefs in Hawaii.This project examines the fundamental connections between seawater chemistry and coral physiology by investigating the modulation of seawater chemistry in the microenvironment surrounding corals. Specifically, this project 1) examines the response of corals to differing carbonate chemistry and 2) characterizes the proton gradient across the corals' boundary layers under differing ocean acidification conditions. Results of this work isolate whether carbonate ions or hydrogen ions have a stronger influence on calcification rates. This work utilizes a state-of-the-art experimental mesocosm facility that combines an automated systems to simultaneously and independently control both total alkalinity and carbon dioxide in the tanks to examine coral response under different carbon chemistry scenarios. Small-scale gradients in carbon chemistry surrounding the corals are being characterized using an innovative solid-state, reagentless sensor capable of making simultaneous measurements of two critical carbon system parameters. Coral biological response variables are quantified during short-term incubations and long-term mesocosm manipulations to understand physiological implications across multiple scales (i.e., individual and community scales) and across boundary layers.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.