Collaborative research: Biocatalytical Filtration and Carbon Cycling in Permeable Shelf Sediments

渗透性砂覆盖了大约70%的大陆架，但沉积到大陆架沉积物中的有机质是如何在渗透性砂中被加工的还不完全清楚。一般来说，砂岩中的成岩过程知之甚少，很大程度上是因为为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，由于孔隙水的快速运输，透水性沉积物中有机物的吸收、代谢和释放动力学与细粒的、相对不透水性的海洋沉积物有本质的不同。最近使用创新技术的现场测量表明，陆架砂作为一个大型生物催化过滤器，可以有效地去除并迅速降解水柱中的溶解/颗粒有机质，这意味着陆架砂在有机物循环中起着核心作用。来自佛罗里达州立大学的研究人员，以及来自弗吉尼亚大学和北卡罗来纳大学的同事，将生成一个全面的数据集，量化对流溶质和颗粒通量，以及受电流诱导孔隙水交换影响的渗透性陆架沉积物的矿化率。这些数据将通过可渗透大陆架砂的耦合运移和反应模型进行整合，从而改进现有的成岩大陆架沉积模型，并为管理人员和决策者提供具有预测能力的工具。这些结果将促进对大陆架的了解，它是最具生产力的，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，项目结果将直接适用于佛罗里达州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区域。在国际范围内，该项目将在可渗透大陆架沉积物区域启动一个新的研究网络，该研究网络将与欧盟现有的一个项目联系起来。

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.