A wild manatee is released back into Florida's Crystal River after being captured for a spot checkup in November 2006.

Many of the 400-plus manatees that come to Crystal River in the fall to bask in the warm waters continue up Florida's Gulf Coast to the Suwannee River, scientists say.

The animals often congregate in the summer at the mouth of the Suwannee, where they forage on large beds of sea grass (see an interactive map of the Suwannee River).

But more and more Florida manatees are wintering in the Suwannee too, because it, like the Crystal, is fed by warm springs that provide comfortable refuge from the chilly Gulf waters.

According to the USGS's Bonde, in a few years the Suwannee could host a manatee population as big and as burgeoning as the one in the Crystal River.

"It's only recently [that] they're starting to use those springs [in the Suwannee]," he said.

"And they're going to build a little population [there], and it's going to grow, if we allow it to grow and we keep giving them … the things they need, like protecting the habitat."

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