EAST LAKE — A team of state wildlife officials went three for three Thursday, capturing each of the manatees reported to be trapped in Lake Tarpon and in danger of becoming ill as water temperatures grow cooler.

But at the end of the all-day operation, they decided their work there work wasn't done.

They'll be back today to scour the lake one last time in search of a mysterious fourth manatee with a scar on its head, captured in a photo taken by a volunteer during Thursday's search.

"We believe there is at least one more, and we'll be back tomorrow to do a thorough search," said Andy Garrett, a manatee specialist for the Florida Fish and Wildlife Conservation Commission, who organized the operation. "The photo shows a marking on the manatee's head that doesn't match any of the ones we captured."

The team of more than 40 people from a variety of organizations — including the wildlife commission, the Clearwater Marine Aquarium, the University of Florida, Tampa's Lowry Park Zoo, the U.S. Geological Survey and the federal Fish and Wildlife Service — will return at 9 a.m. to search for what is believed to be the last remaining manatee in the lake.

The slow-moving mammals first got into the lake in the summer, officials say, but as winter approaches, cooling lake waters have made it inhabitable for the warmblooded animals. They say the manatees swam north from Tampa Bay through a canal, and ventured into the lake when a water control gate near the canal's midpoint was open during Tropical Storm Colin.

Officials hoped the animals would find their way back out during another heavy rainstorm, when the flood gates reopened to drain rising lake water, but that never happened.

They had no choice but to remove the manatees themselves.

Wildlife commission veterinarian Martine DeWitt said she sees the relocation operation as an opportunity to learn more about the species and the environments they thrive in by doing full medical workups on them.

"We are able to take advantage of these opportunities and gain important knowledge of manatees," she said, adding that each of the animals captured was given a microchip containing a record of the medical condition they were found in Thursday.

The operation required seven boats, plus an airplane to spot the mammals from above. The team searched the entire lake, which is five miles long and a mile wide. Less than an hour in, wildlife commission officials spotted the nose of the first manatee peeking above the water on the west side of the lake, just north of Anderson Park.

As they eased their boat closer, a large, circular net was dropped to envelope the animal.

A team of more than 10 people pulled the manatee, massive and struggling, into the boat so it could be taken to a nearby boat ramp, where it was transferred to a larger boat from the Clearwater Marine Aquarium.

A juvenile male estimated at about 9 feet long and weighing about 800 pounds, the manatee was taxied to shore for a medical evaluation to ensure it was healthy enough for the trip to the Safety Harbor City Marina, where it was released.

A second manatee was found shortly before 2 p.m., and a third was located a little more than an hour later. Also male juveniles, both were shuttled to the bay in a specially equipped box truck.

Using the handles of a giant blue stretcher, several members of the rescue team struggled to lift one of the manatees out of the truck and into the water.

"We might need some more people over here," someone yelled, out of breath.

It wasn't until they lowered the stretcher into the bay's warmer waters that everyone let out a sigh of relief followed by a round of cheers.

The manatee flipped its tail, splashing them, before quickly swimming away.

Contact Megan Reeves at mreeves@tampabay.com or (727) 445-4153. Follow @mreeves_tbt.