Collaborative Research: Fragmentation of Marine Snow by Swimming Macrozooplankton

9906827 Alldredge过程改变了海洋中快速下沉的大型碎屑颗粒（称为海洋雪）的大小和丰度，可以显著影响碳的通量及其对远洋生态系统各组成部分的可用性。动物的消耗，细菌的分解，溶解，以及物理混合和电流剪切的解聚都被认为是大颗粒被消耗或转化为更小更缓慢下沉形式的过程。然而，最近来自实验室和现场的令人信服的证据表明，垂直迁移的磷虾，太平洋磷虾，碎片海洋雪在水柱通过其游泳活动。此外，这些影响是显着的，正相关的磷虾丰度。初步的实验室观察证实，这些大型浮游动物的附属物在聚集体附近巡航时产生的剪切应力将海洋雪分解成数量更多，但更小，下沉更慢的颗粒。研究人员将验证和量化这一新过程，并评估动物碎裂相对于自然界中其他颗粒产生和消耗过程的重要性。这项研究将产生关于大型浮游动物游泳对水柱中大颗粒动态的作用的第一个定量信息，揭示生物地球化学过程和动物行为之间的新联系。它将增加我们对浮游动物生物学在海洋粒子动力学、碳循环和小尺度物理学中的作用的理解。这项研究产生的数据可能有助于解释在大多数海洋区域看到的下沉碳随深度的指数损失，以及先前报道的颗粒通量的昼夜模式。

9906827Alldredge Processes which alter the sizes and abundances of large, rapidly sinking detrital particles, known as marine snow, in the ocean can dramatically impact the flux of carbon and its availability to various components of the pelagic ecosystem. Consumption by animals, bacterial decomposition, solubilization, and disaggregation by physical mixing and current shear have all been proposed as processes by which large particles are consumed or transformed into smaller more slowly sinking forms. However, recent compelling evidence from both the lab and the field indicates that the vertically migrating krill, Euphausia pacifica, fragments marine snow in the water column through its swimming activities alone. Moreover, these impacts are significantly and positively correlated with euphausiid abundance. Preliminary laboratory observations verify that the shear stresses created by the appendages of these large macrozooplankton as they cruise near aggregates breaks the marine snow into more numerous, but smaller, and more slowly sinking particles. The investigators will verify and quantify this new process and evaluate the significance of animal fragmentation relative to other particle generating and consuming processes in nature. This research will generate the first quantitative information on the role of macrozooplankton swimming on the dynamics of large particles in the water column, revealing new links between biogeochemical processes and animal behavior. It will increase our understanding of the role of zooplankton biology in particle dynamics, carbon cycling and small-scale physics in the ocean. Data generated by this study may help explain the exponential loss of sinking carbon with depth seen in most areas of the ocean, as well as previously reported diel patterns in particulate flux.