necessary information. The units delineated by 

 this study are described under the heading Level I 

 and II Descriptions in the following subsection, 

 Results. The Level I description lists the factor 

 used to separate that unit from others. For ex- 

 ample, unit A (the U.S. North Atlantic Coast) 

 is different from unit B (the U.S. Middle Atlantic 

 Coast) because the former is affected by the 

 Labrador Current, whereas the Middle Atlantic 

 Coast is affected by both the Labrador Current 

 and the Gulf Stream. 



The Level II descriptions list those criteria 

 used to separate Level II units, plus some addi- 

 tional information. For example, Al (the North- 

 ern Gulf of Maine) differs from A2 (the Southern 

 Gulf of Maine) because it is rockier, has fewer 

 sand and/or cobble areas, and has less extensive 

 marshes. 



The information used in the Level I and II 

 descriptions came mainly from Sverdrup et al. 

 (1942), U.S. Geological Survey (1954), Earle 

 (1969), U.S. Geological Survey (1970), Dolan 

 et al. (1972), Brooks (1973), Joint Federal- 

 State Land Use Planning Commission for Alaska 

 (1973), Selkregg (1974a, 1974b, 1974c, 1974d, 

 1974e, 1974f), Adams et al. (1975), Bureau 

 of Land Management (1975a, 1975b, 1975c, 

 1975d), Great Lakes Basin Commission (1975), 

 Bureau of Land Management (1976a, 1976b, 

 1976c, 1976d, 1976e), General Land Office of 

 Texas (1976), Weaver et al. (1976), and Bureau 

 of Land Management (1977a, 1977b). 



Lateral boundary demarcations and descrip- 

 tions were examined critically by the reviewers 

 (see Appendix for list) of the first draft and 

 other staff members in their respective offices. 

 In many cases the opinion of these reviewers 

 was used to modify both boundaries and descrip- 

 tions. 



Possible options for landward and offshore 

 boundaries are listed in the following subsection. 

 A recommendation is made about which option 

 to select based on both ecological and practical 

 considerations. 



RESULTS 



The results of this project are the options for 

 landward and offshore boundaries (below), the 

 coastal regionalization Level I and Level II 

 boundaries (Table 1, page 18), the Level I and II 

 descriptions (page 7), and the figures located at 

 the back of this report. (Maps shown are Albers 



conical equal area projections; letters and num- 

 bers labeling divisions on the figures correspond 

 to those of Table 1.) The figures are visual de- 

 lineations of the divisions described in Table 1 

 and in the Level I and II descriptions. The Level 

 II divisions represent what are judged to be, in 

 most cases, units which are individual coastal 

 ecosystems or clusters of closely related coastal 

 ecosystems. 



A major portion of the ideas and information 

 used for the list of options for landward and off- 

 shore boundaries is derived from papers by 

 Robbins and Hershman (1974) and Mclntire et 

 al. (1975). The information sources used in the 

 Level I and II descriptions are listed in the 

 Methods section. 



OPTIONS FOR LANDWARD AND OFFSHORE 

 BOUNDARIES 



Landward Boundary Options 



1. Seaward boundary of Bailey's (1977) 

 regionalization. 



Pro — The regionalization is extant. 

 Many Federal agencies and States are 

 committed to its use. 



Con — Not at all designed to give indica- 

 tions of coastal areas. No clear indica- 

 tion of seaward boundary. Does not 

 include in coastal ecosystems Cowardin 

 et al.'s (1977) emergent wetland class 

 (marshes, swamps, etc.). Emergent wet- 

 lands would be included in uplands. 



2. Coastal Zone Management (CZM) inland 

 boundaries. 



Pro — Most boundaries extant, informa- 

 tion collected for characterizations 

 would be directly applicable to CZM 

 problems. 



Con — Not uniform around the country, 

 thus problems of comparability of data. 



3. Mean high water mark, high high tide, 

 etc. 



Pro — Easy to determine. 

 Con — Obviously leaves out a lot of what 

 has traditionally been considered coast- 

 al. 



4. One-hundred-year flood and tidal innunda- 



