QEIB: Energetic Cost of Burrowing

海洋沉积物（主要是泥）覆盖了地球表面的70%，并居住着各种动物（包括蠕虫，蛤蜊）。这些动物是海洋食物网中的重要环节，被许多具有重要商业价值的鱼类所食用。 它们还影响海洋中碳的命运，不仅因为它们以新陈代谢的方式处理碳，还因为它们的挖掘活动混合了沉积物，影响了水和海底之间的物质运输。 因此，穴居动物在全球碳循环中起着重要作用，同时也影响着海洋生境中营养物质和污染物的去向。 尽管有丰富的穴居动物和它们的生态重要性，穴居是令人惊讶的知之甚少相比，其他形式的momentation.This研究调查的物理和新陈代谢的动物如何通过泥打洞，重点是多毛类蠕虫，丰富和生态重要的海洋亲戚蚯蚓。 Dorgan最近修改了一种称为“光弹性应力分析”的技术，用于穴居蠕虫，该技术将用于本研究，以测量蠕虫在穴居时施加在沉积物上的力。Dorgan的研究揭示了动物通过破坏泥土而不是使其变形来挖洞，从而预测挖洞的代谢成本比以前认为的要低得多。 本研究将力学分析与穴居蠕虫的代谢率和沉积物中物质通量的测量相结合，以阐明穴居力学如何影响不同大小的动物在不同类型沉积物中穴居的这些过程，这些结果将为穴居动物影响碳或污染物等物质通过泥泞海底的通量的机制和速率提供重要信息，也将增加我们对动物（和仿生机器人）在沉积物中移动的机制的理解。PI将继续招募和鼓励年轻科学家，特别是女性，并将继续为年轻科学家教授专业发展课程。 她是一个伟大的沟通，以公众，并将积极参与外展和教育的基础上，这项研究。 她还将继续指导有学习障碍的学生;她有阅读障碍，能够分享帮助有类似和其他残疾的年轻科学家的技术。

Marine sediments (mostly mud) cover 70% of Earth's surface and are inhabited by a diverse community of animals (including worms, clams). These animals are important links in marine food webs and are eaten by many commercially important fish. They also affect the fate of carbon in the ocean, not only because they process it metabolically, but also because their burrowing activities mix the sediment and affect the transport of materials between the water and the sea bottom. Therefore, burrowing animals play an important role in the global carbon cycle, and also affect the fates of nutrients and pollutants in marine habitats. In spite of the abundance of burrowing animals and their ecological importance, burrowing is surprisingly poorly understood compared to other forms of locomotion.This study investigates the physics and metabolism of how animals burrow through mud, focusing on polychaete worms, the abundant and ecologically-important marine relatives of earthworms. Dorgan recently modified a technique called "photoelastic stress analysis" for use with burrowing worms that will be employed in this study to measure the forces worms exert on the sediment while they burrow. Dorgan's work revealed that animals burrow by cracking mud rather than deforming it, leading to the prediction that metabolic costs of burrowing are much lower than previously believed. This study combines such mechanical analyses with measurements of metabolic rates of burrowing worms and of flux of materials through the sediment to elucidate how the mechanics of burrowing affects these processes for animals of different sizes burrowing in various types of sediments.These results will provide important information about the mechanisms and rates that burrowers affect the flux of materials such as carbon or pollutants through the muddy sea floor, and will also increase our understanding of the mechanisms by which animals (and biomimetic robots) can move through sediments. The PI will continue to recruit and encourage young scientists, especially women, and will continue to teach courses on professional development for young scientists. She is a great communicator to the public, and will actively participate in outreach and education based on this research. She will also continue her mentoring students with learning disabilities; she has dyslexia and is able to share techniques that help young scientists with similar and other disabilities.