EPA's Vessel General Permit and Small Vessel General

endangered species, threatened species, and designated critical habitat.
The Changing Landscapes of the United States
The continental United States has a land area of about 2.3 billion acres. Since colonial times, the
landscapes of the United States reflect the abundance, distribution and economics of the human
population. In 1790, the United States had a resident population that was slightly less than 4
million and a population density of 4.5 people per square mile. By 2010, that population had
grown to slightly more than 308 million people and the population density had increased to 85
per square mile. Most of the population growth in the United States occurred in urban areas, first
in central cities and later suburbs. In 1910, three times more Americans lived in central cities
than in suburban areas; by 1970, slightly more Americans lived in suburban areas than in either
cities or rural areas. From 1950 to 1996, the urban population increased by 63 percent, the rural
population decreased by 19 percent, and the greatest relative change occurred in the suburban
population, an increase of 274 percent.
Other human activities that have altered the landscapes of the United States include agricultural
practices that include land conversion, sod busting, and applications of pesticides; forest
practices that include timber harvests, silviculture, and the construction of logging roads; mining
practices that include open-pit mining, mountain-top mining, placer mining, heap-leach mining,
and removal of overburden materials; road construction practices that include alteration of land
in the right of way, spraying herbicides to maintain the right of way, and construction of quarries
for source materials; civil works projects that include canals, drainage ditches, projects to deliver
water to arid lands in the western States, projects to drain wetlands in southeastern States,
projects to control flooding in mid-western and eastern States, port construction, projects to
maintain shipping channels, and the construction of more than 8,100 major dams on rivers and
streams in the United States, Puerto Rico, and the U.S. Virgin Islands.
The direct and indirect effects of these changes in land-use and land-cover change have had a
lasting effect on the quantity, quality and distribution of every major terrestrial, aquatic, and
coastal ecosystem in the United States, its territories and possessions. By the mid-1990s, at least
27 types of ecosystems had declined by more than 98 percent (Noss and Murphy 1995). Aquatic
and semi-aquatic ecosystems have not fared much better than terrestrial ecosystems. Between
the 1780s and 1980s, 30 percent of the nation’s wetlands had been destroyed, including 74
percent of the wetlands in Connecticut, 73 percent of the wetlands in Maryland, 52 percent of the
wetlands in Texas, 91 percent of all wetlands in California, including 94 percent of all inland
wetlands (Dahl 1990). From 1982 to 1987, the wetland area throughout the conterminous United
States declined by 1.1 percent and the expansion of urban – suburban metropolitan areas
accounted for 48 percent of this decline (Brady and Flather 1994).
Because of these changes in land use, many of the native plant and animal species that inhabited
those native ecosystems over the past have become extinct or extinct in the wild over the past
200 years. The last passenger pigeon, a species that once numbered in the billions and covered
most of the eastern and mid-western United States, became extinct in 1912. In the same year, the
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