©2, H2S, and CH4), their characterization and chemical composition in 

 seawater, the diagenetic processes resulting in the formation of gases 

 in the sediments, and their flux into the overlying water. 



Variations in space and time of suspended matter in the ocean require 

 further research as do processes occurring at the ocean bottom and the 

 influence of sediments on the chemistry of the water column. Specifically, 

 mechanisms and rates of in situ production and consumption of sus- 

 pended material need to be determined both in the water column and at 

 the bottom. The occurrence of trace elements in calcareous and silicious 

 tests needs further elucidation, as do the rates of reaction (e.g., solution) 

 of such tests. Similar studies on the hydrated metal oxides and particu- 

 late organic carbon are needed. The composition and flux of organic 

 carbon and the preferential formation of minerals (e.g., high magnesium 

 calcite over aragonite) are important research areas. 



A host of organic compounds is dissolved in the sea, yet their com- 

 position, distribution, and ecological importance are unknown. An 

 inventory of organic chemicals in the marine environment needs to be 

 established, and their origin, age, composition, and fate need to be 

 determined. Processes, mechanisms, and rates — both in rapid-turnover 

 areas as well as low-productivity locations — need to be studied. For 

 example, what is the role of organic matter in sedimentation, diagenesis, 

 and air-sea interaction? What is the nature of the interaction between 

 organic matter and the inorganic components of the ocean? 



Many aspects of the influence of the ecosystem on chemical distribu- 

 tions are unknown, specifically with respect to heavy metals. Knowledge 

 of the distributions, forms, and fate of these chemicals is presently in- 

 adequate to define their role in stimulation and control of the biosphere. 

 Little is known of the synergism and antagonism of heavy metals in 

 this system. The low levels of chemical constituents that control biologi- 

 cal systems and the competitive nature of membrane transport sites 

 require that low concentrations, both of nutrients and of antimeta- 

 bolites (such as arsenate and trace metals), be considered simultaneously. 

 Backleakage of nutrients and of organic metabolites significantly alters 

 water chemistry; the rates of backleakage are important terms in the 

 flux relations in any models constructed. Realtime rates of nutrient uptake 

 are needed and the regulatory processes that control and determine the 

 characteristics of nutrient fields need further investigation, especially 

 for incorporation into models. 



The marine environment is a dynamic system. Our degree of under- 

 standing of this system will be directly related to our understanding 

 of chemical fluxes within it. Important questions concern how much 

 material is being added to the present-day ocean from each of the various 

 sources and how much is being removed to each of the various sinks. 

 Do addition and removal rates change as functions of time? Information 



