Collaborative Research: NSF-BSF: Photophysiology and bio-optics of Red Sea mesophotic corals

热带珊瑚礁是生物多样性的热点，为世界各地众多沿海社区提供重要服务。全球和地方压力的结合导致浅水珊瑚礁群落前所未有的退化。最重要的是，水温升高加上过度的太阳辐射会导致珊瑚白化，这是指珊瑚共生藻类的丧失，被视为对浅水珊瑚礁未来生存的主要威胁。因此，人们对深水沃茨越来越感兴趣，因为预期它们可以免受在浅水沃茨更常见的极端环境影响。令人惊讶的是，珊瑚在阳光几乎无法到达的栖息地蓬勃发展，30-150米深的中光珊瑚礁生态系统（MCE）的特点是独特的珊瑚群落，可以作为浅水珊瑚的避难所。在这个项目中，我们的目标是研究光捕获机制，使珊瑚在这种光有限的条件下茁壮成长，使用多学科的方法，结合了最先进的生物工程，生物光学和珊瑚生理学工具。由于珊瑚是最有效的水生光合系统之一，研究珊瑚生物光学还可以发现新的捕光机制，并开发新的珊瑚光子材料，以构建更有效和可持续的光生物反应器。这是一个美国-以色列两国项目，旨在通过一系列公共外展活动促进国际合作和多样性，包括博物馆展览和创意体验设计，以支持STEM中代表性不足的群体的参与。光是珊瑚礁深度梯度沿着珊瑚群落变化的关键驱动力。然而，辐照度对珊瑚的存在和生长的重要性主要是在浅水物种中研究的，而且在光照条件极其有限的情况下，中光珊瑚如何茁壮成长的知识在很大程度上是缺乏的。这项研究将提供一个定量评估的光收集在中光深度，并提供新的见解生物光学和辐照度的作用，在结构化珊瑚群落。为了实现我们的目标，我们将采用跨学科的方法来建立中光珊瑚的生物光学特性。我们的工作流程结合（1）在埃拉特的珊瑚礁实地考察（红海，以色列）收集和分析珊瑚沿着深度-辐照度梯度，（2）基于实验室的光微传感器测量结合内源性绿色荧光蛋白和光合测定分析;（3）光学相干断层扫描和微计算机断层扫描，以表征组织和骨骼形态，用于开发3D光-使用蒙特卡罗模拟捕获模型;和（3）一种新的3D生物打印方法，以实验方式确定珊瑚骨骼形态对光合作用的作用。总之，这项研究将提供必要的基础理论模型，试图了解中光珊瑚礁生态系统的空间分布和预测其对环境变化的反应，因此提供了一个实用的工具，珊瑚礁管理和conservation.This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。

Tropical coral reefs are hotspots of biodiversity and provide critical services to numerous coastal communities worldwide. A combination of global and local stressors have led to the unprecedented degradation of shallow water coral reef communities. Most importantly, elevated water temperatures combined with excess solar radiation can cause coral bleaching, which describes the loss of the coral’s symbiotic algae and is regarded as the major threat to the future existence of shallow-water reefs. Thus, corals from deep waters are gaining interest as they are expected to be buffered from extreme environmental impacts more commonly experienced in shallow waters. Surprisingly, corals are flourishing in habitats where sunlight barely reaches, and 30-150 m depth mesophotic coral reef ecosystems (MCEs) are characterized by unique coral communities that could serve as a refuge for shallow water corals. In this project, we aim to study the light-harvesting mechanisms that allow corals to thrive under such light-limited conditions using a multidisciplinary approach that combines state-of-the-art bioengineering, bio-optics, and coral physiology tools. Since corals are among the most efficient aquatic photosynthetic systems, studying coral bio-optics can also lead to the discovery of novel light-harvesting mechanisms and the development of novel coral-inspired photonic materials to build more efficient and sustainable photobioreactors. This is a US-Israel binational project that aims to promote international collaboration and diversity through a range of public outreach activities, including museum exhibitions and the design of creative experiences to support the participation of under-represented groups in STEM.Light is a key driver of coral community change along the coral reef depth gradient. However, the importance of irradiance for the existence and growth of corals has been predominantly studied in shallow species, and knowledge of how mesophotic corals thrive despite extremely limited light conditions is largely lacking. This study will provide a quantitative assessment of light-harvesting at mesophotic depths and offer novel insights into the role of bio-optics and irradiance in structuring coral communities. To achieve our goal, we will employ an interdisciplinary approach to establish the bio-optical properties of mesophotic corals. Our workflow combines (1) in-situ coral reef fieldwork in Eilat (Red Sea, Israel) to collect and analyze corals along a depth-irradiance gradient, (2) lab-based light microsensor measurements combined with analyses of endogenous green fluorescent protein and photosynthetic assays; (3) optical coherence tomography and microcomputed tomography to characterize tissue and skeletal morphology for the development of 3D light-capture models using Monte Carlo simulations; and (3) a novel 3D bioprinting approach to experimentally determine the roles of coral skeleton morphology on photosynthesis. Altogether, this research will provide the essential basis for theoretical models that seek to understand the spatial distribution of mesophotic coral reef ecosystems and predict their responses to environmental change, therefore offering a practical tool for reef management and conservation.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.