Florida's Toxic Algae

More than a century ago, the Everglades were drained for development, agricultural production and, subsequently, flood control. A network of canals, levees and water-control structures has fundamentally changed the natural ecosystem. Today the Everglades is half the size it was a hundred years ago.

Lake Okeechobee, the “liquid heart” of the Everglades, and the rivers that drain it to the Gulf of Mexico and Atlantic Ocean — the Caloosahatchee and St. Lucie rivers, respectively — are part of this human-altered system that helps sustain the greater Everglades region.

Much of what remains of the historic Everglades is heavily polluted by phosphorous, nitrogen and mercury from urban and agricultural development. The lake in particular has been besieged by nutrient pollution for decades, causing unprecedented blooms of toxic algae. Making matters worse the U.S. Army Corps of Engineers flushes this toxic algae down to the estuaries, where the algae and nutrients worsen red tide.

The Corps’ unmitigated discharges of polluted water into the Caloosahatchee and St. Lucie rivers from Lake Okeechobee are killing countless marine species, crippling local economies, and violating U.S. laws enacted to protect the environment.


In 2018, joined by other conservation groups, the Center launched a lawsuit to force the Corps to update its management of Lake Okeechobee. The significant harm to the rivers and their estuaries — and to endangered species that depend on them, from Florida manatees to sea turtles and coral — must stop.

Grizzly bear in Yellowstone National Park by Jim Peaco/National Park Service