Wildlife in the Florida Everglades

A black vulture. The health of the park dubbed the River of Grass has suffered greatly in recent years, hurt by polluted runoff generated by sugar farms that lie in the centre of the ecosystem Photograph: Joe Raedle/Getty

A flock of flamingos takes flight. The vital southward passage of water from Lake Okeechobee in central Florida to the Everglades also has become increasingly impeded by industry, posing another threat to the park Photograph: Andy Newman/EPA

Clouds and shoreline trees reflect in an Everglades canal. The land sale, comprising about 300 square miles, would allow US Sugar to continue farming for six years before giving up its leases, effectively putting the country's cane sugar maker out of business Photograph: Raul Touzon/National Geographic/Getty

A roseate spoonbill. The rebuilding project was originally planned as a $7.8bn (£3.9bn) joint effort with the federal government, but funding to resuscitate the park has proven hard to come by Photograph: Medford Taylor/National Geographic/Getty

A crocodile observes at the water surface. Florida state has dedicated about $2.4bn to the effort so far, with Congress allotting much less Photograph: Carlos Barria/Reuters

Wetlands in the Everglades. In the wake of the deal, US Sugar is expected to cease operations in Florida, where cane harvesting brought the company an estimated $400m in annual profits Photograph: Farrell Grehan/Corbis

A dragonfly hangs onto a stick. Although humans have lived in the Everglades for thousands of years, it was not until 1882 that the region began to be drained for agricultural or residential use Photograph: Joe Raedle/Getty

A trio of red-bellied woodpeckers. The ecosystems in Everglades national park have suffered significantly from human activity, and the repair and restoration of the Everglades has become a politically charged issue Photograph: National Geographic/Getty

Salt marsh pink. The Everglades has an immense capacity for water storage, due to the sponge-like permeable limestone underneath the exposed land Photograph: Phil Schermeister/Corbis

An American green tree frogs rest in the shade of a palm tree. Rising sea levels caused by global warming are another threat to the future of the park. Since 1932, ocean levels at Key West have steadily risen by over 20cm, which could have disastrous consequences for the area Photograph: Mary Knox Merrill/The Christian Science Monitor/Getty

Unlike most other US national parks, Everglades national park was created to protect a fragile ecosystem instead of safeguarding a geographic feature. Thirty-six species designated as threatened or protected live in the park, including the Florida panther (left) Photograph: Galen Rowell/Corbis