Collaborative Research: Pteropod Swimming Behavior as a Bio Assay for Ocean Acidification

海洋酸化（OA）构成了严重的威胁，特别是对从海水中沉淀碳酸钙的生物。翼足类是一种具有文石外壳的生物，它是高纬度生态系统的关键。使用OA，翼足类动物的外壳会变薄，因为文石是高度可溶的。随着壳变薄，它会改变动物的质量分布和浮力，从而影响运动，并通过运动影响所有依赖运动的行为，如觅食、交配、躲避捕食者和迁徙模式。较低的壳重将被较小的粘液网抵消，可能会降低摄入率和碳通量率。这项跨学科的研究依赖于翼足类软体动物Limacina helicina在自然环境中的游泳行为的生物学研究，并通过3D层析粒子图像测速和计算流体动力学（CFD）对游泳流体动力学进行流体力学分析。这项工作将：(a)确定螺旋螺旋藻如何使用它的“翅膀”（副足）来推动自己；(b)检查其运动运动学是否提供有效的推进；(c)确定影响游泳轨迹和“摆动”的因素；(d)综合所有数据和见解，为翼足类动物游泳行为作为OA生物测定的潜在用途提供指导。失去这些人为增加二氧化碳的哨兵可能会导致生态转变，因为这些翼足类动物摄取了南大洋近一半的初级产量，也是鱼类等营养水平较高的主要食物资源。由于运动数据可以立即收集，因此本提案中正在开发的生物测定可以作为OA对浮游生物这一重要成员即将发生的影响的早期预警。学生和研究人员将在丰富的跨学科研究环境中合作，与生物海洋学家、流体力学专家和CFD专家合作，并配合在南极工作所需的团队精神。通过在挪威和帕尔默站建立一个独一无二的三维断层成像系统，用于可视化浮游生物周围的流动，我们增加了最先进技术的国际交流。目前研究的教育影响将成倍增加，包括在研究团队中，本科生，高中生和代表性不足的少数民族，除了研究生。

Ocean acidification (OA) poses a serious threat, particularly to organisms that precipitate calcium carbonate from seawater. One organism with an aragonite shell that is a key to high latitude ecosystems is the pteropod. With OA, the pteropod shell will thin because the aragonite is highly soluble. As the shell thins, it changes the mass distribution and buoyancy of the animal, which will affect locomotion and through it, all locomotion dependent behavior such as foraging, mating, predator avoidance and migratory patterns. A lower shell weight will be counterbalanced by a smaller mucus web potentially decreasing ingestion rates and carbon flux rates. This interdisciplinary research relies on biological studies of swimming behavior of the pteropod mollusk Limacina helicina in their natural environments with fluid mechanics analyses of swimming hydrodynamics via 3D tomographic particle-image velocimetry and computational fluid dynamics (CFD). This work will: (a) determine how the L. helicina uses its 'wings' (parapodia) to propel itself; (b) examine whether its locomotory kinematics provide efficient propulsion; (c) identify the factors that influence swimming trajectory and 'wobble'; and (d) synthesize all data and insights into guidelines for the potential use of pteropod swimming behavior as a bioassay for OA.The loss of these sentinels of anthropogenic increases in CO2 may result in an ecological shift since thecosome pteropods are responsible for ingesting nearly half the primary production in the Southern Ocean and also serve as a primary food resource to upper trophic levels like fish. Since locomotory data can be gathered immediately, the bioassay being developed in this proposal may serve as an early warning of the impending onset of OA effects on this important member of the plankton. Students and researchers will collaborate in a rich interdisciplinary research environment by working with a biological oceanographer, a fluid mechanics expert and a CFD expert coupled with the teamsmanship needed for work in the Antarctic. By setting up a one-of-a-kind 3D tomography system for visualizing flow around planktonic organisms in Norway and at Palmer Station, we increase international exchange of state-of-the-art techniques. The educational impact of the current research will be multiplied by including in the research team, undergraduate students, high-school students and underrepresented minorities in addition to graduate students.