Manatees like to congregate in the area during cold weather and when it is high tide.
This story originally appeared on Time.
About 300 manatees swam into Florida's Three Sister Springs on Monday, prompting the temporary closure of the one-acre plot of water to swimming and kayaking.
Laura Ruettiman, an environmental education guide at the Springs, told USA Today that manatees like to congregate in the area during cold weather and when it is high tide. She said the area reopened on Tuesday, but will close again when the mammals return to the interior of the springs during high tide.
The U.S. Fish and Wildlife Service issued the temporary closure of Three Sisters Springs after manatee watch volunteers initially counted a total of 293 manatees on Monday afternoon.
Ruettiman attributed the rise in numbers to greater protection in the area and to habitat loss in other parts of the state. "We have a record number this year," she said. "We have 150 more manatees here than have ever been recorded in the past."