Hot Water

Of power plants and manatees

Environmental activists are usually happy when power companies close down coal-fired electric plants in favor of cleaner, more efficient ones. But that's not currently the case in Florida, where, in a textbook example of the law of unintended consequences, the closure of coal-fired plants threatens an already endangered species.

There are fewer than 2,000 manatees, the large sea mammals that resemble whiskered baked potatoes, in U.S. coastal waters. It turns out they thrive in water warmed by coal-fired electric power plants.

Walking along a Tampa Bay canal a few years ago, I was delighted to spy a small herd of manatees. They were there because the Tampa Electric Company's plant uses water from the canal to cool its steam pipes. After being used as a coolant, the water is returned to the canal about 10 degrees warmer. The manatees love it. Tampa Electric also pumps fresh water through two hoses into the discharge pool for the manatees to drink.

Manatees die from cold stress if water temperatures fall below 68 degrees Fahrenheit, so in winter they congregate by the hundreds to bask in the warm outflows from electric plants. Wildlife experts generally agree that the power plants have helped the species survive.

Now some wildlife conservationists are beginning to worry about what will happen when the aging power plants are shut down. Organized Fishermen of Florida spokesman Jerry Sansom, who has tracked manatee issues for years, told the Orlando Sentinel, "It's a disaster waiting to happen." Five manatees died of cold stress when a Jacksonville plant shut down a couple of years ago.

A task force of scientists, power plant executives, and manatee conservation advocates are looking for solutions. One suggestion is that solar-powered warm-water refuges be built to harbor manatees during the winter months.