How is the Everglades Ecosystem Threatened?

For most of its history, that massive rain-fed series of wetlands, lakes and rivers we call the Everglades flowed free and clean starting just below Orlando and through Lake Okeechobee south to the tip of the Florida peninsula, east and west toward both coasts. The Everglades covered almost 3 million acres.

Native peoples lived in harmony with the land, but then settlers began to arrive.

"In the past hundred years, people have been digging canals and building dams in the Everglades so they could take water out of it and develop agriculture and build homes," says Dr. Tom Van Lent, senior scientist, Everglades Foundation. "We've built so many canals and drained so much water that the natural flow is interrupted."

In fact, as the twentieth century dawned, early conservationists saw the dredging of the Everglades as the smart, progressive thing to do.

John Gifford, the area's premier conservationist, called it "the greatest conservation project in the United States," and Gov. Napoleon Broward said it would be a "sad commentary" on the state if Florida couldn't drain the Everglades. After the devastating 1928 hurricane, a dike was built at the southern end of Lake Okeechobee to protect against flooding. The Everglades, once fed by the natural overflow from the lake, was now dependent on rainfall and a series of man-made canals and dams.

As a result of all this interference, the Everglades is now half its original size, and broken up by 1,800 miles of canals and dams, water control points and pump stations that divert the natural flow east and west to supply the coastal towns and cities.

"Historically, the overflow from Lake Okeechobee is the main source of water for the Glades, but with the construction of canals, the whole dynamic of the flow has been affected," points out Dr. Rosanna Rivero, the Foundation's Geographic Information System (GIS) scientist. "Now the water has to be released to estuaries and the water levels have been affected. There's too much water in the wet years, and not enough in the dry."

Sixty years ago, demographers predicted South Florida's population would reach two million people by the 21st century. It's already at six million, and expected to double in the next 50 years.

All that growth has squeezed the Everglades as development reached inland from both coasts to accommodate the burgeoning population. And with the people came pollution, especially phosphorus from the fertilizers used in the agricultural areas north and south of Lake Okeechobee. Where low levels of phosphorus once kept the Everglades thriving with sawgrass and tree islands, nutrient overload resulting from agricultural runoff has produced an overabundance of cattails, algae and duckweed, which in turn alters the natural habitat of the area's wildlife.

Now, the wading bird population has declined 80 percent since the 1930s, and 67 species that once called the Everglades home are either threatened or endangered, along with the fishing industry and wildlife tourism. "A lot of high quality water is not getting into the system," says Dr. Stephen E. Davis, wetland ecologist, Everglades Foundation.

As a result, the plants and animals that evolved in a once-pristine ecological system can no longer depend on the natural balance that nurtured their development The Everglades are not a series of independent environments, but a large and complex system, and all its parts need each other. When Lake Okeechobee is harmed, for example, the impact can be felt throughout the Everglades ecosystem.