Fluxes of Dissolved Organic Matter form Marine Sediments

9302120 Burdige以前的工作已经开始说明海洋沉积物中的溶解有机碳通量在海洋和沉积碳循环中发挥的重要作用。同时，溶解有机氮(DON)的海底通量代表了沉积氮再矿化的一个很难量化的组成部分，这在海洋和沉积氮循环中可能同样重要。因此，这项提案的目标是继续研究海底DOC通量，并开始研究海底DOC通量。孔隙水DOC和DON研究也将与这些通量研究一起进行。在一定程度上，这项工作将考察孔隙水DOC和DON的特征，因为它们与DOC和DON对底栖生物通量的控制有关。我们提议的工作将在加州大陆边缘切萨皮克湾的地点进行。对大陆边缘沉积物的研究尤其令人感兴趣，因为有几条证据表明，边缘沉积物中的碳和氮循环(以及边缘沉积物中DOC和DON的底栖通量)可能在海洋碳和氮循环中发挥重要作用。考虑到所选地点的一系列特征，这些数据将为控制DOC和DON底栖生物通量的因素提供进一步的见解。这些结果将用于改进对全球海洋沉积物DOC通量的估计，并启动对海底DOC通量在海洋和沉积物氮循环中的作用的类似研究。最后，这些新的结果将被用来批判性地检验一个模型，该模型可以描述海底DOC通量和底栖碳再矿化总速率之间的关系。

9302120 Burdige Previous work has begun to illustrate the important role that dissolved organic carbon (DOC) fluxes from marine sediments play in oceanic and sedimentary carbon cycling. At the same time, benthic fluxes of dissolved organic nitrogen (DON) represent a poorly quantified component of sedimentary nitrogen remineralization that may be similarly important in oceanic and sedimentary nitrogen cycling. The goals of this proposal are therefore to continue studies of benthic DOC fluxes, and to begin studies examining benthic DON fluxes. Pore water DOC an DON studies will also be carried out in conjunction with these flux studies. In part, this work will examine the characteristics of pore water DOC and DON as they relate to the controls on benthic fluxes of DOC and DON. Our proposed work will be carried out at sites in the Chesapeake Bay on the California continental margin. Studies in continental margin sediments are of particular interest since several lines of evidence suggest that carbon and nitrogen cycling in margin sediments (and benthic fluxes of DOC and DON from margin sediments) may play important roles in oceanic carbon and nitrogen cycling. Given the range of characteristics among the sites chosen, the data will provide further insights into the factors controlling benthic fluxes of DOC and DON. These results will be used to improve estimates of the global DOC flux from marine sediments and to initiate a similar examination of the role of benthic DON fluxes in oceanic and sedimentary nitrogen cycling. Finally, these new results will be used to critically examine a model which may describe the relationship between benthic DOC fluxes and overall rates of benthic carbon remineralization.