CRYSTAL RIVER, Fla. (AP) - An environmental watchdog group wants to close a popular warm water source for manatees to swimmers and
divers.

Public Employees for Environmental Responsibility filed a notice Monday of intent to sue. That gives the U.S. Fish and Wildlife Service 60 days to close Kings Spring in Crystal River or face a lawsuit.

An estimated 100,000 tourists swim annually with manatees in and around the spring.

The watchdog group is worried that swimmers drive manatees out of the warm water the marine mammals need when temperatures fall.

Cold stress caused hundreds of manatee deaths this winter.

PEER has previously attempted to end the "swim with manatees" activities sanctioned only in Citrus County, but federal officials declined to make any changes.
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