COASTAL OCEAN MARGINS PROGRAM 



Goal 



DOE's Coastal Ocean Margins Program is 

 providing a better definition of three different major 

 marine coastal systems in the Northeast, the Southeast, 

 and the Southwest. The program is developing im- 

 proved understanding of marine transport and better 

 identification of the origin of fate of marine system 

 contaminants derived from energy activities or other 

 sources. Specifically, the goal of the Coastal Ocean 

 Margins Program is to understand the transport of 

 materials — both natural and human-derived — within 

 coastal regions and between coastal and open ocean 

 areas. 



Rationale 



The coastal oceans are the first line receptacle 

 for gathering discharges from rivers and estuaries and 

 are important in materials exchange among the atmos- 

 phere, open ocean, and continents. Because the coas- 

 tal oceans have high levels of nutrients and physically 

 driven erosional processes, they contain much higher 

 concentrations of particles, both inert and those 

 derived from biological productivity. These particles 

 can actively sorb dissolved inorganic and organic 

 chemicals and contaminants from the water and be- 

 come the major vehicles of transport of natural and 

 human-derived materials in the oceans. Increased 

 biogenic production, due to high-nutrient inputs to the 

 coastal region, may mitigate some toxic substances by 

 sorbing them to make large particles that are 

 deposited in sediments or transported from the shore 

 by oceanographic exchange processes. The increased 

 phytoplankton production also may mitigate atmos- 

 pheric CO2 levels by accelerating the uptake of CO2 

 into the ocean. We are only now beginning to under- 

 stand in what forms and by what pathways con- 

 taminant-carrying particles are dispersed around the 

 world's oceans, and whether materials are isolated by 

 burial in shallow or deep sediments, dispersed through 

 biological food chains, or decomposed and redis- 

 solved to be diffused broadly into the ocean. 



Although the same fundamental processes are 

 involved in biogenic production, transport, and 

 decomposition on the continental shelves, circulation 

 along the coastal margins generally is controlled by 

 coastline shape, flow of water from rivers and es- 



tuaries, wind force and direction, and bottom topog- 

 raphy. On the ocean side of the shelf, exchanges are 

 complex and controlled by massive boundary currents 

 such as the Gulf Stream along the East Coast and the 

 California Current off the West Coast. The distribu- 

 tion and intensity of ocean processes thus are different 

 for each geography or region. For this reason, the 

 Coastal Ocean Margins Program is subdivided into 

 three major regions: the Northeast, Southeast, and 

 Southwest Coasts of the United States. 



The three regional programs share a set of 

 general objectives against which the range of 

 geographical differences are compared. These objec- 

 tives are: 



• To determine movement of water masses 

 and their chemistry on the coastal shelf and 

 slope so as to identify how dissolved and 

 particulate materials are transported and 

 distributed 



• To quantify amounts and determine rates of 

 biological and geochemical particle trans- 

 formations that take place on the continen- 

 tal margins 



• To determine the productivity of living or- 

 ganisms (phytoplankton, bacteria, 

 zooplankton) over temporal and spatial 

 scales and the fate of these organic particles 

 both on and off the shelf. 



Research Plan and Current Program 



Within the Coastal Ocean Margins Program, 

 regionally directed studies are being conducted to 

 define currents, upwelling events, coastal boundary 

 layers, eddy diffusion, flushing rates, and sediment 

 transport. Through the use of biogeochemical tracers, 

 the nature and extent of estuarine and atmospheric in- 

 puts of energy- and weapons-related materials to coas- 

 tal marine waters are being determined. Fluxes of 

 particulate matter, dissolved organic and inorganic 

 compounds, and nutrients within water masses and be- 

 tween boundary layers (e.g., nearshore waters versus 

 deep water, sediment/water interfaces) are being 

 derived. 



Coastal Ocean Margins Program 



December 1988 



