185 



happen to be the major sources of income because of the nature of the 

 estuary and its location which prevent its development as a commercial 

 shippinf^ facility. 



The San Dieo^o economy, although heavily dependent upon the mili- 

 tary and shipping activities in the bay, has diversified to the extent 

 that it is no longer completely dependent upon such uses of the bay. 

 At the same time there has been a growing demand for recreational 

 uses of the bay. Evidence of the local residents' interest in the bay for 

 recreation, tourism, and commercial uses can be found in their willing- 

 ness to invest substantial sums of money in facilities to prevent pollu- 

 tion of the bay by municipal wastes. 



Mission Bay, a separate estuary in the San Diego area, is an example 

 of the recreational potential to be found in an estuarine system. How- 

 ever, this special study points up the fact that the best use of an estuary 

 may not come about naturally. Rather, it shows that a planned develop- 

 ment program with adequate investments are necessary to achieve 

 optimal use of an estuary. 



In summary, then, it can be seen that the major uses of estuaries vary 

 from one estuary to another, depending upon historical development 

 and suitability for specific uses. However, the primary points indicated 

 by these various estuary reviews are: (1) estuaries are adaptable to 

 several different uses; (2) current use of any given estuary is not the 

 sole indicator of the estuary's value; and (3) with adequate effort the 

 recreational and social aspects of an estuary can become vital parts 

 of that estuarine system. 



Section 4. Measures of Value and Importance of the 

 Estuarine Zone 



The discussions of values of individual uses and the case studies 

 of specific estuarine systems present a confusing picture of the rela- 

 tionship of estuarine uses to economic indicators. 



Estimates of the direct gross economic benefit of the estuarine zone 

 to the residents of the coastal counties can be made. The estimates of 

 economic activity generated by the presence of Narragansett Bay in 

 Rhode Island give a conservative annual economic benefit of $920 

 )3er capita, $420 of this in personal income. Average personal income 

 for all of the coastal counties is, according to Bureau of the Census 

 figures, $500 per capita greater than the average for the remainder of 

 the country. The total economic activity generated by this additional 

 personal income then amounts to about $1,100 per person, using the 

 Narragansett Bay multiplier values. 



The total direct economic benefit of the estuarine zone to the resi- 

 dents of the coastal counties is then about $60 billion in terms of addi- 

 tional economic activity stimulated by the presence of estuarine sys- 

 tems. This is not a measure of the total economic activity of the 

 estuarine zone, but only of the "value added" to the total economic 

 activity of the coastal counties by the presence of the estuarine zone. 



Such gross means can give only an order-of-magnitude estimate of 

 even the direct economic value of the estuarine zone and cannot pos- 

 sibly reflect either indirect benefits or the social importance of the 

 estuarine zone, much less its ecological value. 



