to answer the question stated. 



The criteria used for separation of Level I and 

 II divisions are as follows: 



Level I The forcing functions of the system 

 Level II The major constraints of the system 



The lateral (i.e., perpendicular to the shore) 

 boundaries of Level I and II divisions, determined 

 by the above criteria, and descriptions of these 

 divisions are given. Level III division separations 

 are not made. If Level III divisions are needed, 

 they should be the products of a special study on 

 a specific Level II division, and the homogeneity 

 of the response by the system should be the chief 

 criterion used for separation. A list of options for 

 landward and seaward boundaries of Level I, II, 

 and III divisions is given with the pros and cons of 

 using each of the options. 



The most appropriate landward boundaries for 

 Level I, II, and III divisions are either the marine 

 and estuarine landward boundaries, as defined by 

 the National Wetlands Inventory classification 

 scheme (Cowardin et al. 1977), or the landward 

 limit of the major coastal processes which occur 

 in each division. In some cases these two bound- 

 aries are the same. 



Seaward boundaries should be set as either the 

 edge of the continental shelf (as indicated by 

 Cowardin et al. 1977) or at the seaward boundary 

 of the major coastal processes which are occurring 

 in each division. For landward and seaward bound- 

 aries, the lines delimited by the National Wetlands 

 Inventory classification system (Cowardin et al. 

 1977) are the more practical option. 



In some cases the political boundaries of the 

 United States are regarded as boundaries of coastal 

 ecosystems because of the chief use of the region- 

 alization. These boundaries are highly artificial. A 

 list is given of more practical lateral boundaries of 

 coastal ecosystems which do cross political bound- 

 aries of the United States. 



LITERATURE CITED 



Adams, J. B., L. C. Gerhard, J. C. Ogden, and J. 

 Bowman. 1975. Potential national natural land- 

 marks, U.S. Virgin Islands. West Indies Lab., 

 Fairleigh Dickinson Univ., for the Natl. Park 

 Serv. 82 pp. 



Bailey, R. G. 1977. Ecosystems and ecoregions of 



the United States. Map, Scale 1 -.7,500,000, U.S. 

 Forest Serv. 



Briggs, J. C. 1974. Marine zoogeography. McGraw- 

 Hill, New York. 475 pp. 



Brooks, H. K. 1973. Geological oceanography: 

 Historical background and regional relation- 

 ships. Pages IIE-1 to IIE-49 in J.J.Jones, R. 

 Ring, M. Rinkel, and R. Smith, eds. A sum- 

 mary of knowledge of the eastern Gulf of 

 Mexico: 1973. State Univ. System, Fla. Inst. 

 Oceanogr., St. Petersburg, Florida. 



Bureau of Land Management. 1975a. Visual gra- 

 phics, offshore southern California, Outer Con- 

 tinental Shelf lease sale 35. 



. 1975b. Visual graphics, northern Gulf of 



Alaska, Outer Continental Shelf lease sale 39. 



1975c. Visual graphics, Gulf of Mexico 



and Atlantic Ocean, Outer Continental Shelf 

 lease sale 41. 



. 1975d. Visual graphics, eastern Gulf of 



Mexico, Outer Continental Shelf lease sale 41. 

 . 1976a. Visual graphics, offshore the Mid- 



Atlantic States, Outer Continental Shelf lease 

 sale 40. 



. 1976b. Visual graphics, Cape Hatteras 



Planning Unit, Outer Continental Shelf lease 

 sale 43. 



. 1976c. Visual graphics, western and cen- 



tral Gulf of Mexico, Outer Continental Shelf 

 lease sale 47. 



. 1976d. Visual graphics, lower Cook 



Inlet, Outer Continental Shelf lease sale. 

 . 1976e. Visual graphics, western Gulf of 



Alaska, Outer Continental Shelf lease sale 46. 

 . 1977a. Visual graphics, offshore the 



North Atlantic states, Outer Continental Shelf 

 lease sale 42. 



. 1977b. Visual graphics, Blake Plateau 



Planning Unit, Outer Continental Shelf lease 

 sale 43. 



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