Taghon, Fuller, Kerkhof, Reimers : OCE-9872042 The occurrence of subtidal pumping is a common, but poorly understood feature of many continental shelves. This group of PIs propose to test the hypothesis that the low organic carbon content of shelf sands is a by-product of rapid bacterial mineralization of organic matter (OM), fueled by a high rate of supply of OM and oxygen as bottom water is advected through the upper layer of sediment. Both laboratory and field studies are proposed. In the lab, the PIs propose to use controlled conditions in a seawater flume to attempt to measure how variations in seabed topography, sediment permeability and flow velocity affect the cycling of OM in these sands. The field component will be conducted at the site of a permanent seabed observatory (LEO15) off the coast of New Jersey, where advection driven fluxes through sandy sediments are thought to occur. The results of this study will allow the PIs to quantify sedimentary fluxes and improve our understanding of this process. This will have a broad impact on our understanding of the cycling of organic matter and associated elements in coastal oceans.
