Warm Springs for Winter Manatees

A large manatee can top 1000 pounds and eat 15% of its weight in seagrass each day.

That may sound hardy, but manatees are actually very sensitive. There are three species, all adapted only to the constant warm waters of the tropics.

But the West Indian manatee has found a way to survive Florida winters by taking advantage of the state’s geology.

As temperatures drop, manatees leave coastal waters and swim up rivers toward headwater springs.

Florida has hundreds of springs, more than any other state, and some are huge, pumping out millions of gallons a day.

The springs are fed by rainwater that percolates through Florida’s limestone bedrock, flows underground, is heated by geothermal energy, then emerges to form warm, clear pools that feed rivers.

The spring pools are home to large ecosystems of many species -- including, in winter, manatees, who come by the hundreds to spend the cold months lounging, and eating.

Like so many things in nature, the springs are under pressure from human development. Florida cities and agriculture pull water from the aquifer, reducing flow into the pools. Fertilizer seeps into the groundwater and enters the springs, clogging them with algae.

Despite that, the manatees’ numbers are increasing, due to conservation efforts by Florida preservation groups. A success story of shared resource use that can hopefully sustain these remarkable creatures long into the future.