The nation's coastal areas are among its most significant natural resources. Coastal zones include a variety of ecological niches, in either marshy wetlands or beach and rocky areas. Partially submerged lands subject to tidal action are a rich biological factory, providing nutrients for numerous varieties of fish and birds and spawning grounds for the majority of the fish caught commercially off the U.S. coasts. Wetlands act as valuable protection against flooding due to minute rises in ocean levels and help maintain coastal water quality by containing bacteria and other organisms that break down organic wastes discharged from secondary treatment plants. Both marshlands and other types of coastal areas offer an invaluable aesthetic and recreational resource.

Pressures from residential populations expanding toward coastal areas, together with increasing industrial development in the coastal zone, have resulted in drastic reductions in the amount of natural shoreline left untouched. Concern among state and federal policymakers over this trend has led to enactment of various schemes for coastal protection. Some states, including California, have established programs to extend comprehensive protection to almost all of the land contiguous to coastal areas. California's Coastal Zone Conservation Act¹ provides for interim regulatory control over lands between the three-mile limit seaward and 1,000 yards inland of mean high tide, and for a permanent planning jurisdiction from the three mile limit to either five miles inland or to the nearest mountain range, whichever is closer.