point up the need for more measurements of this type. More equihbrium 

 methods — both heterogeneous and homogeneous — should be developed 

 and applied, and the development of in situ kinetic methods should be 

 explored. 



One of the great unknowns in trace-metal speciation studies is the 

 role of organic ligands. The characterization of classes of compounds 

 and individual organic species is a well-developed field of chemistry. 

 However, the enormous variety and overall low concentration of organic 

 species in the ocean make in-situ measurements improbable. Previous 

 comments on sampling and standardization obviously apply here. Once 

 these steps are taken, the enormously powerful battery of new techniques 

 used by organic and biochemists can be applied — Fourier Transform 

 infrared and nuclear magnetic resonance spectroscopy, computer- 

 assisted gas chromatography, mass spectrometry, gel permeation, and 

 high-pressure liquid chromatography. 



Finally, chemical oceanographers must be encouraged to adopt and 

 adapt the highly developed analytical methods used in other areas of 

 science. Examples are the sensitive analytical methods developed for 

 lunar rock analysis and the recent advances in cUnical analytical chem- 

 istry. 



THE ROLE OF ESTUARIES IN 



MODIFYING SEA WATER COMPOSITION 



Streams bring a burden of dissolved and particulate substances to 

 the sea, and in the region of encounter between fresh water and seawater 

 a variety of processes occur to alter locally the composition of seawater. 

 The natural phenomena occurring in this region provide the context 

 for understanding the effect of man-induced changes in the quality and 

 quantity of materials supplied to the estuarine zone. The coastal zone, 

 therefore, provides an environment for modifying the composition of 

 seawater that may be as important as the open-ocean environment. 

 Some fundamental problems in this area are 



1 . The flux of dissolved elements to the ocean from streams is known 

 fairly well on a worldwide average basis for the major components. 

 However, seasonal changes in the chemical composition of streams as 

 they enter the ocean are not well understood, and a few reliable data 

 on trace constituents are available. 



2. The quahty and quantity of sediment loads brought to estuarine 

 environments by rivers require attention. For example, the total quantity 

 of sediment delivered by the Susquehanna River as the result of hurricane 

 Agnes in 1972 equaled the total sediment load transported in the past 

 50 to 100 years. This large supply of fresh water and sediment seriously 



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