BRIGANTINE, N.J. — A wayward manatee was loaded aboard a transport jet bound for his home state of Florida on Thursday after being rescued from chilly, murky waters near a New Jersey oil refinery.

Ilya left from Atlantic City International Airport for a Coast Guard base in Miami, with the Miami Seaquarium as the ultimate destination.

The docile sea cow was pulled from a creek at the ConocoPhillips oil refinery in Linden on Monday and had been recuperating at the Marine Mammal Stranding Center in Brigantine.

"We're very relieved," said Bob Schoelkopf, co-director of the center. "We spent a lot of days worrying about him."

Federal wildlife authorities kept the rescue a secret, fearing a crush of media and well-wishers could stress the animal.

Ilya needed to be rescued because New Jersey's waters are too cold this time of year for him to survive for long. He had been migrating as far north as Massachusetts for the past decade but dithered too long in New Jersey this year.

The manatee was huddling near an outfall pipe in Morses Creek, a small tributary of the Arthur Kill, a narrow waterway that separates northern New Jersey from Staten Island, N.Y. The water temperature in the creek was 53 degrees — well below the 68 degrees manatees need to survive.

"This animal had no chance if it stayed there much longer," Schoelkopf said.

It took more than 30 rescuers to corral Ilya on Monday in a rescue attempt that lasted 7 1/2 hours. It involved stretching a 300-foot net from shore onto the bow of a boat that was then maneuvered around the manatee to ensnare it, in the same manner that fishermen use a seining net to catch fish in shallow water.

Once they got the 1,100-pound, 10-foot-long manatee onto the muddy creek bank, a crane from the refinery lifted him onto a stretcher that was then loaded onto a truck and driven 84 miles south to the stranding center.

Ilya chowed down on crates of lettuce as he regained his strength, downing $300 worth of produce in two days.

"All this thing did was eat," Schoelkopf said. "But that's a good thing."

He appeared to be healthy and in good shape to endure the two-hour flight to Florida aboard a Coast Guard C-130 plane, resting on matting and covered with wet towels, a veterinarian at his side.

Ilya has been tracked by scientists since 1994 as he made his way up and down the East Coast and is identifiable by a distinctive scarring pattern on his tail. Normally content to frolic in Florida's warm waters, he created a commotion in northern climes this summer, surfacing in Massachusetts, Connecticut and Maryland.

Scientists say it is unusual but not unheard of for manatees to venture this far north in search of food during the summer.