Collaborative Research: Biocatalytic Filtration and Carbon Cycling in Permeable Sediments

渗透性砂覆盖了大约70%的大陆架，但是对于沉积到大陆架沉积物中的有机物如何在渗透性砂中被处理还不完全清楚。一般而言，砂岩中的成岩过程了解甚少，主要是因为针对细粒沉积物开发的标准方法无法准确模拟砂岩中的原位条件。然而，由于快速孔隙水运输，在渗透性沉积物中的有机物的吸收，代谢和释放的动力学是根本不同的细粒，相对不透水，海洋沉积物。 最近使用创新技术的原位测量表明，陆架砂作为一个大型的生物催化过滤器，有效地去除和快速降解溶解/颗粒有机物从水柱，这意味着陆架砂在有机物的循环中发挥着核心作用。 来自佛罗里达州立大学的研究人员，沿着来自弗吉尼亚大学和北卡罗来纳州大学的同事，将生成一个全面的数据集，量化对流溶质和颗粒通量，以及受电流诱导的孔隙水交换的可渗透陆架沉积物中的矿化率。这些数据将通过一个可渗透陆架砂的耦合运输和反应模型加以整合，从而改进现有的成岩陆架沉积模型，并为管理人员和决策者提供一个具有预测能力的工具。这些结果将促进对大陆架的了解，大陆架是最具生产力、经济上最重要的，同时也是最受威胁的海洋环境。在地方一级，项目成果将直接适用于佛罗里达的阿巴拉契科拉湾地区的管理和保护工作，该地区是指定的研究地区。在国际范围内，该项目将在可渗透的陆架沉积物领域建立一个新的研究网络，该网络将与欧洲联盟的一个现有方案相联系。

ABSTRACTOCE-0424967Permeable sands cover approximately 70% of the continental shelves but it is not fully known how organic matter that settles to the shelf sediment is processed in permeable sands. In general, diagenetic processes are poorly understood in sands largely because standard approaches developed for fine-grained sediments fail to accurately mimic in situ conditions in sands. However, due to rapid porewater transport, the dynamics of uptake, metabolism, and release of organic matter in permeable sediments are fundamentally different from those in fine-grained, relatively impermeable, marine sediments. Recent in-situ measurements using innovative techniques suggest that shelf sands act as a large biocatalytic filter that efficiently removes and rapidly degrades dissolved/particulate organic matter from the water column, implying that shelf sands play a central role in the cycling of organic matter. Researchers from Florida State University, along with colleagues from University of Virginia and University of North Carolina, will generate a comprehensive dataset quantifying advective solute and particle fluxes, and mineralization rates in permeable shelf sediment subjected to current-induced pore water exchange. The data will be integrated by a model of coupled transport and reaction in permeable shelf sands, permitting improvement over existing diagenetic shelf sediment models, and generating a tool with predictive ability for managers and policy makers. These results will foster understanding of the continental shelf which is the most productive, economically most important, and at the same time the most threatened oceanic environment. On the local level, project results will be directly applicable to management and conservation efforts in the Apalachicola Bay region of Florida, which is the designated study area. On an international scale, the project will start a new research network in the area of permeable shelf sediments that will be linked to an existing program for the European Union.