Wetlands
Losses in the United States
1780's to 1980's
Summary of Findings 1780's - 1980's
The land area that now comprises the United States originally contained almost 392 million acres of wetlands (221 million acres in the lower 48 states). Historical estimates of wetland distribution by state indicate that 21 states possessed three million acres or more of wetlands.
Considerable change in wetland distribution and abundance has taken place since the 1780's (refer to Figures 3 and 4). In the conterminous United States, an estimated 104 million acres of wetlands remained as of the 1980's. This amounts to a 53-percent loss from the original acreage total. The 50-state total indicates that an estimated 274 million acres remain.
In the 1980's wetlands constitute only 5 percent of the land surface in the lower 48 states; 12 percent if Alaska and Hawaii are included. The State of Alaska has the vast majority of wetland acres. An estimated 170 million acres are believed to exist in Alaska alone. This represents approximately 45 percent of the State's total surface area.
Among the lower 48 states, Florida, Louisiana, Minnesota, and Texas are the 4 states with the greatest wetland acreage. Other states with considerable wetlands include Alabama, Georgia, Maine, Michigan, Mississippi, North Carolina, South Carolina, and Wisconsin. The data on wetlands lost during this 200-year timespan indicate that the State of Alaska has lost the lowest percentage of its original wetland acreage (estimated less than 1% loss). The states of Hawaii, New Hampshire, and Rhode Island have lost the fewest wetland acres overall, 7,000, 20,000 and 38,000 acres respectively. However, this amounts to a 12-percent loss of wetlands statewide for Hawaii, 9 percent loss for New Hampshire, and a 37-percent loss for Rhode Island.
Ten states-Arkansas, California, Connecticut, Illinois, Indiana, Iowa, Kentucky, Maryland, Missouri, and Ohio-have lost 70 percent or more of their original wetland acreage. Overall, the data indicate that 22 states have lost 50 percent or more of their original wetland areas. The state with the highest percent loss of wetlands is California (an estimated 91 percent loss from the 1780's to the 1980's). Florida has lost approximately 9.3 million acres of wetlands during this 200-year timespan.
With the exception of Alaska, New Hampshire, and Hawaii, no state has lost less than 20 percent of its original wetland acreage.
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