Hundreds of manatees congregate in Florida refuge to escape chilly seas

• Three Sisters Springs closed to swimmers and kayakers
• 400 of the marine mammals leave Gulf of Mexico to gather in river system

A popular Florida wildlife refuge has been closed to swimmers, thanks to an influx of hundreds of manatees.

It's estimated that as many has 400 manatees have crowded into the Three Sisters Springs, a refuge about 65 miles north of Tampa. About 1,000 manatees live in the Kings Bay and Crystal River ecosystem, of which Three Sisters Springs is a part. A large number of the marine mammals are wedged in a spring called Idiot's Delight.