Cold Weather Tough on Florida's Manatees

Cold weather has taken its toll on Florida's manatee population.

THREE SISTERS SPRINGS, Fla. Feb. 17, 2010— -- Bulbous, gray masses floated in the clear water, skimmed the surface and snorted for fresh air as volunteers, doctors and researchers watched from the shore.

Two manatees, CC and Captain, were released back into the wild today, and yesterday five more were brought to the warm springs in Florida's Crystal River, about 70 miles north of Tampa. It's a second chance at life after their much-needed rehabilitation.

Tanya Ward was one of the team members who released the manatees into the wild yesterday. She and several others transported them from trucks to the water, one by one, carrying each in a bulging stretcher. After a few wriggles, each manatee sank into the blue-green pool and drifted away.

When the animals' radio-tracking transmitters disappeared from sight, it signified a bittersweet victory for those who had spent anywhere from one to two years rehabilitating the young animals.

Ward, who has helped nurse some of the released manatees back to health, is a Florida mammal zoo keeper at Lowry Park Zoo in Tampa, Fla. The zoo cares for 16 or 17 manatees at any given time as part of their rescue and release efforts. Sea World also rehabilitates manatees, and those released today had been recovered at the animal park in Orlando.

Cold Weather Puts Manatees in Danger

Manatees have suffered from Florida's recent below-average temperatures. They can only tolerate water that's at least 68 degrees, and the Gulf of Mexico this time of year can reach the lower 50's. At the springs in the Crystal River refuge, however, the water is 72 degrees year round.

"With such a cold snap and such a long-lasting cold snap, some of the manatees haven't been able to make it," Ward said.

The manatees were found near Florida's west coast, near Collier, Lee and Citrus counties.

Those that were orphaned, without a mother to feed them and guide them to warmer waters, were at risk of drowning. Ivan Vicente, visitor service specialist with the U.S. Fish and Wildlife Service who attended yesterday's release, explained that the manatees' metabolism eventually shuts down in cold water. They can't control their buoyancy, and it becomes difficult for them to contract and expand their lungs.

Myra, released yesterday into the springs along with fellow manatees Baby Coral, Nephew, Coral Lee and Little Nap, was one of the orphaned manatees rescued from the Caloosahatchee River in Ft. Myers, Fla.

"We hope the other manatees will take her in and out of the spring," Ward said. "Hopefully she will learn that way because she did not have that time with her mom."

A Safe Haven for Manatees

Releasing orphaned manatees doesn't come without risks. Even though there's always a possibility for accidents or a potential struggle to assimilate, Ward stays hopeful.

"There's always that chance that something could happen to her, but we'd much rather give her a chance to be free and survive in the wild and have her own calf one day," she said.

Before being released the manatees were belted with monitoring devices -- they'll be tracked by the U.S. Geological Survey, which Ward describes as a manatee "babysitter."

Bob Bonde, a biologist with the U.S. Geological Survey, has studied manatees for more than 32 years. He is part of the team that will monitor the released manatees at three timepoints: three months from now, then six months and finally, one year post-release. If the manatees show signs of deteriorating health, they will be put back in captivity, he said.

"Because they don't have any past experience, it's generally passed on from mother to calf, they're a high-risk situation," Bonde said.

Crystal River is considered a safe haven for endangered manatees, and refuge workers are trying to make the environment a safer one.

Michael Lusk, manager of the Crystal River National Wildlife Refuge, said these are a few of the natural springs left in Florida that are not protected.

Lusk said partners of the refuge hope to purchase this land within the next few months and make it an official piece of the national wildlife refuge system.

During extreme cold weather, these areas have seen a record number of manatees. Refuge workers have observed more than 200 manatees visit Three Sisters Springs, which comprises two acres, and this shows the importance of protecting the refuge, Lusk said.

"As manatees were dying south of here we had no manatee deaths due to cold in this area," he said.

ABCNews.com contributor April Dudash is a member of the University of Florida ABC News on Campus bureau.