JACKSONVILLE, Fla. -

After months of rehabilitation, a manatee and her calf have been released back into the wild.

The manatees were in a much stronger state Wednesday than when they were found in February near the JEA power plant and the Dames Point Marina.

Zoo officials said the endangered species were suffering from cold stress because they never migrated south.

The 1-year-old calf called Son, short for Jacksonville, and her mom JEA, pronounced Gia, named after the utility company the manatees were found near, waited patiently at the Bert Maxwell Boat Ramp on Wednesday.

SLIDESHOW:  Manatee mom, calf released in river

Sea to Shore Alliance, an organization that monitors manatees in the winter, found the sea cows in about 3 feet of water suffering from cold stress.

"Manatees need to be in water temperatures above 68 degrees or they can start developing cold lesions on their body," said Jaime Vaccaro, of Lowry Park Zoo in Tampa. "It's kind of like our version of frost bite, and a lot of time that can be detrimental. It can ultimately result in death."

Instead of migrating south for the winter, the manatees and six others stayed in the St. Johns River, and the water got too cold.

"They will find some warm water sites where the water is just a little bit warmer and they'll hang in those sites, and they don't want to head into the cooler river water to make that trek south like they normally do," said Nadia Gordon, of the Florida Fish and Wildlife Conservation Commission.

The alliance, along with the Jacksonville Zoo and the FWC helped rescue the mammals. They were taken to the Lowry Park Zoo to be rehabilitated.

The manatees were put in warm water, fed and given antibiotics, and after just a couple months, mom and her baby were healthy again.

"Soon he'll be able to kind of go off on his own, and we're hoping the mom can reproduce again," Vaccaro said. "And it's just adding to the population and getting them back out there healthy, whereas if they weren't brought into us, it could have been a different story."

For many manatees, it's a different story.

There are only about 5,000 of the endangered species left in the Sunshine State. They're often found entangled, orphaned and injured by boat propellers.

"We see them come in with a lot of different injuries, whether man-made or natural, and they hang in there," Vaccaro said. "We do our best to give 100 percent, and they're giving it as well, and when you get to see them come back out, it's really nice."

If you see a manatee or any marine mammal in distress, injured, dead or tagged, call the Florida Fish and Wildlife Conservation Commission at 1-888-404-FWCC.