Unusually cold weather killing Florida's manatees

ST. PETERSBURG, Florida (Reuters) - Unusually cold weather last winter killed Florida's endangered manatees at a record rate, a report said on Friday.

During 2010, a record 699 manatees have died in Florida, according to the Florida Fish and Wildlife Conservation Commission's Research Institute.

Of those, 244 were attributed to cold weather and many of the 271 undetermined deaths were also likely caused by weather. In most years, the leading cause of manatee deaths is from collisions with power boats.

The latest surveys estimate there are only about 5,000 of the chubby marine mammals left in Florida waters.

"We are very concerned about the unusually high number of manatee deaths this year," Gil McRae, the director of the institute, said in a statement. "The cold-related deaths this past winter emphasize the importance of warm weather habitat to the Florida manatee."

The previous record of 429 manatee deaths was set in 2009 but only 56 of those were caused by cold weather.

Manatees are protected under the Endangered Species Act and the state of Florida has enacted laws to require slower motor boat speeds in some waters to prevent manatee accidents.

Manatees require warm, shallow water to survive. They often swim near power plants in the winter for warmth.

(Writing by Robert Green, editing by Greg McCune)