PROGRAM TITLE: Ocean Margins Program (OMP) ACTIVITY STREAM: Processes SCIENCE ELENENT:Biogeochemical Dynamics DEPARTMENT OF ENERGY DESCRIPTION: The Department of Energy has traditionally supported long- term interdisciplinary studies of coastal ocean systems as part of its concern for the dispersal and fate of energy-related materials in the environment. In response to a review conducted by the National Research Council's Ocean Studies Board Committee on the Coastal Ocean, the DOE restructured its regional coastal-ocean programs into a new Ocean Margins Program (OMP) during FY 1992. The primary objectives of the OMP are to: (1) quantify the ecological and biogeochemical processes and mechanisms that affect the cycling, flux, and storage of carbon and other biogenic elements at the land/ocean interface; (2) define ocean-margin sources and sinks in global biogeochemical cycles; and, (3) determine whether continental shelves are quantitatively significant in removing carbon dioxide from the atmosphere and isolating it via burial in sediments or export to the interior ocean. To meet these objectives, research is being supported to: (1) quantify the physical, biogeochemical, plant, animal, and microbial mechanisms, processes, and interactions that affect the input, assimilation, and transformation of carbon in coastal waters and sediments; and (2) develop and apply new instrumentation and molecular biological techniques to obtain high frequency in-situ measurements of the environmental and biological factors affecting carbon fluxes in the ocean. The OMP approach involves conducting studies along the U.S. continental shelves, utilizing instrument moorings and ship tracks to measure watermass movements, currents, and upwelling dynamics; spatial and temporal concentrations of chemical species and particles; biological productivity, ecological dynamics, and consumption within lower-level food chains; and biogeochemical fluxes of organic particles, nutrients, and mineral phases in the water-column and sediments. Future plans involve melding this research into a field program to assess the exchange of carbon and other biogenic elements between estuarine systems, the shelf, and the interior ocean near Cape Hatteras, NC, where burial and cross-shelf exchange is expected to be maximum. STAKEHOLDERS: The DOE Ocean Margins Program is linked with the U.S. JGOFS and GLOBEC Programs because there is compelling evidence that the input of nutrients to coastal areas from both land-based sources (via rivers) and interior-ocean sources (via coastal upwelling and frontal exchange), cause as much as 50% of the total primary production of the global ocean to occur along the ocean margins. As a result, these areas may play an important role in the cycling and flux of CO2 and biogenic elements within the global ocean. The OMP and its scientific researchers are also interacting with IGBP's LOICZ Program and several U.S. Agency programs concerned with quantifying the processes that affect the transport and fate of water, carbon, nutrients, biota, sediments, and pollutants in changing coastal environments, including EPA, MMS, NASA, NOAA, ONR, and NSF's Program on Coastal Ocean Processes. SHORT-TERM POCICY PAYOFFS: Quantitative information on the flux and fate of CO2 and biogenic elements at the land/ocean interface is important for the IPCC and other integrated assessments of sources and sinks in the global carbon cycle. In addition, quantitative information on coastal processes underpins policy decisions on resource management in changing coastal areas. PROGRAM CONTACT:Curtis R. Olsen, DOE, ER-74, Washington, DC 20585, 301-903-5329