Drs. Anderson and Biscaye propose to construct a carbon budget for an upper slope region of the Middle Atlantic Bight. Previous studies in this region led to the controversial hypothesis that export of Corg from continental margin represents a major pathway for transfer of CO2 from the atmosphere to the deep ocean. The source term for their Corg budget will be provided by a large number of primary productivity and sediment trap flux measurements to be obtained during a DOE-funded study of Shelf-Edge Exchange Processes. The work will include independent approaches to evaluate the rate of Corg reimeralization at the upper slope as well as the rate of Corg burial. One approach will include coupling measured solid phase Corg distributions in sediments trap fluxes and independently-determined rates of sediment accumulation and sediment mixing to infer rates of Corg burial, consumption within the mixed layer, and rapid remineralization at the sediment-water interface. The complemetary approach will use benthic flux chambers to measure the flux of 02 into the sediments, which will be stoichiometrically converted into Corg consumption rates, and flux of C02 out of the sediments. Chamber-derived fluxes will be compared to Corg remineralization rates inferred from solid phase studies as a test for internal consistency and reliability of the Corg remineralization rates. Enumeration of benthic community biomass will also provide turnover rates for live carbon in the sediments. Carbon fluxes determined in this study will help resolve the controversy regarding the importance to global C02 cycle of the transport of margin-derived Corg to the deep sea and will further provide a quantitative relationship between Corg fluxes and benthic ecosystem energy requirements.
