CAREER: Geochemical and Biochemical Factors Controlling Skeletal Nucleation and Their Impact on Coral in a Changing Ocean

成核是海水溶液形成碳酸钙晶体的第一步，是珊瑚骨架的基本组成部分。最近，海洋的pH值变得更酸，这可能会影响成核，从而影响珊瑚的生长。本研究将测量各种受控条件下的成核速率，以确定控制骨架成核动力学的重要过程，即环境、生化或两者的某种组合。此外，该项目将以新的方式将科学和教育结合起来，通过增加美国土著学生对海洋学的参与，帮助改善地球科学的多样性。这位科学家将与华盛顿大学的一位人类学教授合作开设一门课程，内容是地质学和海洋学如何告诉我们海洋是如何随着时间的推移而变化的，不同的文化是如何适应这些变化的，并考虑人类？美国在这个不断变化的星球上的未来。选修该课程的四名本科生将有资格获得暑期实习，参与研究项目。珊瑚骨骼成核只有在溶解的离子能够克服能量障碍自组装成钙化结构时才有可能。这个屏障的大小是由文石饱和状态和界面能控制的，这意味着成核是地球化学和生物化学控制的产物，目前还没有得到很好的约束。珊瑚古代用物已被广泛用于研究深层环境过程，因此，对初始阶段成核的认识，将极大地促进对珊瑚古代用物的使用和适用性的认识。该研究小组已经开发出一种成核试验来测量体内成核速率。这将在各种受控条件下用于测量生化和地球化学控制对成核的影响。在由于海洋酸化而改变的海洋化学的压力下，成核速率很可能会受到很大的影响，因此开始发展关于海洋酸化对珊瑚骨骼成核影响程度的知识是至关重要的。

Nucleation is the first step needed to form calcium carbonate crystals from a seawater solution and represents the building block of coral skeletons. Recently, the pH of the ocean has become more acidic which can impact nucleation, and as such, coral growth. This research will measure nucleation rates under a variety of controlled conditions to identify the important processes controlling skeletal nucleation kinetics, namely environmental, biochemical, or some combination of the two. Additionally, the project will merge science and education in new ways to help improve the diversity in Earth Sciences by increasing the participation of Native American students in oceanography. Partnering with an Anthropology professor at the University of Washington, the scientist will develop a class on how geology and oceanography teaches us about how the oceans have changed over time, how different cultures have adapted to these changes, and consider human?s future on a changing planet. Four undergraduate students taking the class will be eligible for summer internships to participate in the research project. Coral skeletal nucleation is only possible if dissolved ions can overcome an energetic barrier to self-assemble into a calcified structure. The magnitude of this barrier is controlled by the aragonite saturation state and interfacial energy, meaning that nucleation is a product of both geochemical and biochemical controls that are currently not well constrained. Coral paleoproxies have been widely used to study environmental processes through deep time, and therefore, understanding of the initial step, nucleation, should greatly further understanding of the use and applicability of coral paleoproxies. The researcher's group has developed a nucleation assay to measure in vivo nucleation rates. This will be used under a variety of controlled conditions to measure the impact of the biochemical and geochemical controls on nucleation. Under the pressures of changing ocean chemistry due to ocean acidification, it is likely that nucleation rates will be greatly impacted, and it is crucial to begin developing knowledge on the magnitude of the effect ocean acidification will have on coral skeletal nucleation.