IV-50 



be possible to modify the environmental conditions to some 

 extent, but for the present the existing environmental limitations 

 must be accepted.* 



This discussion has so far considered only those environmental 

 factors which dominate the estuarine environment, not the 

 environment itself. Management's fundamental concerns, however, 

 are with the appearance and quality of trie inaividual environment 

 and with the variety and usefulness of the life forms a par- 

 ticular environment will support. 



There are many life forms which exist throughout the estuarine 

 zone, most of them being particularly adaptable forms of plank- 

 ton, crustaceans, and fish. In addition to these, however, 

 tnere are some less adaptable life forms which require a limited 

 range of conditions to survive and yet others wnich need a wery 

 specific environment to reproduce. 



Maine lobsters, for example, are numerous in the Hortn Atlantic 

 estuarine region, scattered in the Middle Atlantic, and cannot 

 be found in other regions. The commercial shrimp, on tne other 



*0ne environmental factor, river flow, is already being freely 

 modified—sometimes with less understanding than may be desirable, 

 A case study on damages associated with river flow modification 

 in Charleston Harbor is presented in Chapter 5 (IV-1-3). 



