QUINCY — Staff and volunteers at the New England Aquarium Animal Care Center packed 28 sea turtles, all recovering from hypothermia, into padded crates and loaded them onto in three large Saturday morning for a trip to warmer waters in Florida.
The aquarium saw a record number of hypothermic turtles this winter, said Tony LaCasse, and aquarium spokesman.
About 400 sea turtles were stranded on the Massachusetts coast in the winter. Aquarium staff and volunteers took 242 sea turtles in for treatment, breaking the past record of 140 turtles in 1999, LaCasse said.
“We had days when we shipped out 17 loggerheads to other facilities and took in 20,” LaCasse said. “We literally had boxes of turtles back here.”
Aquarium experts are unsure why so many turtles were stranded this winter, said Connie Merigo, the aquarium’s stranding program manager.
Merigo’s theory, she said, is that last year’s mild winter may have caused some to stay in the Gulf Stream instead of swimming into the Gulf of Mexico.
Most of the reptiles en route to Florida Saturday were endangered Kemp’s ridley sea turtles, the smallest one weighing about 5½ pounds. The Kemp’s ridley are a smaller breed, with adults reaching between 24 and 36 inches long.
They were joined by two green sea turtles and seven larger loggerhead turtles — the largest, which has been recovering at the University of New England in Biddeford, Maine, weighing in at more than 100 pounds.
The turtles, most stranded on Massachusetts beaches in November and December, suffered chronic hypothermia — not acute hypothermia that comes with a sudden cold spell, but one that develops during weeks of swimming in near-freezing water, LaCasse said.
The cold slowed their blood circulation, which often led to damaged flipper tips, pneumonia, and injured eyes, he said.
Most of the cold-stricken turtles have been released or transferred to marine animal hospitals outside New England.
About 15 more will stay in the aquarium’s care for a few more months as they recover from bone fractures, pulmonary problems, and damaged organs, LaCasse said.
Kristen Patchett, marine animal rehabilitation coordinator at the University of New England, brought five adolescent loggerhead turtles that have been in the university’s care since December. Sea turtles are born on shore but crawl to sea after they hatch and stay there the rest of their lives, with only females returning to lay eggs once every few years.
When one washes up, researchers have the opportunity to study a noncaptive sea turtle unusually closely, Patchett said.
“The strandings are pretty much the only way that students . . . can get experience working with them,” she said.
Thirteen of the turtles are part of a longer sea turtle study at the New England Aquarium. Researchers monitor their blood levels, hormones, and behavior from rescue to release, said Kerry McNally, an aquarium biologist.
“Basically, we’re trying to see the health values from intake to release,” she said before she boarded an SUV to Florida on Saturday, wearing a small silver turtle charm on her necklace. One of the turtles to be released is named for her.
The caravan’s planned route follows I-95, with planned stops in Connecticut, Baltimore, Virginia, and South Carolina to pick up more turtles, most of which were stranded on Massachusetts coasts and transferred elsewhere when tanks in the aquarium’s Quincy center got crowded.
Team members will tweet their progress along the way.
They expect to arrive at a state park in Jacksonville, Fla. with nearly 50 turtles in tow Sunday and perform a few final blood tests on the reptiles.
Then they plan to line the turtles up 10 to 15 feet away from the water, five or 10 at a time, and watch them scurry into the sea.
“These sea turtles haven’t smelled that distinct ocean smell [in months],” LaCasse said. “You can literally see the first smell that registers with them.”