113 



Section 6. Energy and Management in the Biophysical 

 Environment 



Solar energy and gravitational energy are the basis for everything 

 that happens naturally in the estuarine zone. This discussion of the 

 biophysical environment has been concerned primarily with the trans- 

 formation of these energies into forms useful in living processes and 

 exploitable by man. Three different sets of subdivisions of the bio- 

 physical environment were used in this discussion (fig. IV.1.39). 



Differences in the external environment divide the estuarine zone of 

 the United States naturally into 10 geographic regions, each subject 

 to a particular combination of the external influences of tide, ocean 

 currents, wave action, sedimentation, and climate. This subdivision 

 into estuarine biophysical regions gave broad ranges of conditions in 

 each region, but the importance of local coastal conditions in deter- 

 mining energy flows via water movement paved the way for a subdi- 

 vision of the estuarine zone according to 11 morphological groups 

 having similarities in water movement, circulation, and the ability to 

 rid themselves of wastes. 



A subdivision according to ecological communities is also based 

 primarily on geographical location, but again local coastal conditions 

 make it necessary to identify small ecosystems within each major 

 grouping. This subdivision rests not only on the shape and form of 

 coastal areas, but also on the composition of the estuarine bottom. 



As an illustration of the relationships of these groupings, consider 

 the ways to classify a group composed of all the deliverymen in the 

 United States. They work in 50 States (the biophysical regions) ; 

 they work in cities, towns, and rural areas (the morphological classifi.- 

 cation) ; they deliver different kinds of things, such as groceries, 

 clothes, furniture, and hardware (the ecosystems) . 



Each of these different groupings of the estuarine zones is signifi- 

 cant to management. The biophysical regions are contiguous geo- 

 graphic zones with similar general environmental conditions that 

 would be appropriate for an institutional management unit. The mor- 

 phological grouping can serve as a guide to useful physical modifica- 

 tion and necessary waste treatment, while the ecological grouping tells 

 what can and can't be done with the living resource. 



REFEaiENCES 



IV-1-1 Tlie material presented in this chapter was distilled from a number of 

 sources. While individual citations are given in some cases, the com- 

 plexity of the source information precludes detailed references. The 

 more informative general references are these : 



Kuenen, Ph. H., Marine Geology, New York, Wiley, 568 pp (1950) 

 Shepard, F. P., Submarine Geology, New York, Harper and Row, 



557 pp (1963) 

 Harvey, H. W., The Chemistry and Fertility of Sea Waters, Cam- 

 bridge, England, Cambridge University Press, 240 pp (1963) 

 Sverdrup, H. V., M. W. Johnson, and R. H. Fleming, The Oceans, 



Englewood Cliffs, N.J., Prentice-Hall, 1087 pp (1942) 

 Pickard, G. L., Descriptive Physical Oceanography, New York, 



MacMillan, 199 pp (1963) 

 Von Arx, W. S., An Introduction to Physical Oceanography, New 

 York, Addison Wesley, 422 pp (1962) 



