South Florida, the southeastern tip of the United States, was once a
23 000 km2 unbroken marshland of sawgrass and small tree islands. The
Kissimmee-Okeechobee- Everglades region formed a system of rivers, lakes
and wetlands that controlled water flow, mitigated seasonal flooding,
filtered sediment, and provided habitats for hundreds of species.
In 1948, the federal government started draining the Everglades and building
dikes and canals for agricultural uses. There was a large loss of biodiversity,
with some 10 million alligators killed between 1960 and 1965. Populations
of herons, egrets, storks and spoonbills had, by 1979, decreased by 90
per cent. By 1998, 68 species were endangered or threatened with extinction.
Agricultural intensification produced sugar cane, tropical fruit and
winter vegetables. However, that benefit is now threatened by encroachment
from urban areas. Since 1998, the US Army Corps of Engineers has been
attempting to restore the natural function of the Everglades. The estimated
cost is US$7.8 billion, which covers only the first stage of the restoration
effort, which is expected to require more than three decades.
|Landsat data: USGS/EROS Data Center
Compilation: UNEP GRID Sioux Falls