Two natural modes of input of terrestrial and man-mobilized material into the ocean are 

 atmospheric fallout and river discharge. The SEAREX Program has increased our understanding 

 of the former. Riverine transport studies are more complex since influxes donot go directly into 

 offshore waters of regional seas or global oceans, but first pass through estuaries and other 

 nearshore environments. River-carried material therefore does not represent actual riverine 

 fluxes to the ocean proper. Other important modes for introduction of material, especially for 

 wholly artificial substances, are through direct discharge from land via pipelines and through 

 dumping by ships at sea. 



In the case of naturally occurring contaminants, such as metals, it is also important to quantify 

 natural influxes. These include emissions from tectonic spreading centers and hyrothermal 

 vents and influxes from runoff other than rivers, such as glaciers. These sources need to be 

 placed in perspective with regard to the role that rivers play. The net input to the open ocean is 

 that material which survives chemical and biological removal and reinjection as it traverses the 

 estuarine environment and the coastal-open ocean boundary. Physical characteristics of these 

 areas also play an important role in transport. 



The chemical components of this estuarine transport study would require from $2 to $4M of 

 new support per year over a five-year period. 



3. Ocean Lithosphere and Ridge Crest Processes (Chemical Component). An 



initiative in Geological Oceanography describes the geological, chemical, and biological aspects of 

 understanding how lithosphere and ridge crest processes work. The support needed for studies of 

 sulfide mineralization, vent water chemistry and seawater leaching of porous crust will be $2M 

 per year. 



4. Recruitment Mechanisms (Chemical Component). This initiative in Biological 

 Oceanography requires studies of chemical input to access food chain shifts resulting from 

 dissolved material in the water column. Between $1 M and $2M per year will be required to 

 perform these chemical studies of recruitment. 



5. Tracer Studies in WOCE. A critical step in any effort to predict the role of the ocean as 

 a sink (e.g., for fossil fuel 002) and its ability to transport chemicals both vertically and 

 horizontally is creation of models of ocean circulation and mixing. Present models are limited 

 and a major obstacle to their future development is a lack of data with which to constrain them. 

 Chemical tracers offer the best means of providing these constraints. As a result, one of the 

 major objectives of TTO, initiated in 1978 jointly with the Department of Energy, is to obtain a 

 fully three-dimensional picture of tracer distributions throughout the world ocean. 



Large field-intensive oceanographic research, such as study of tracers, depends upon 

 well-maintained and efficiently operated ship support facilities comprised of sampling 

 equipment, in-situ measurement devices, analytical instruments, computers, and staff to 

 operate these facilities to provide requisite data handling and management capabilities. With the 

 advent of large-scale oceanographic field studies lasting several months, permanent technical 

 staff are needed to handle support activities efficiently. 



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