Mystic ― On Thursday morning, rescue staff at Mystic Aquarium’s Milne Center were doing medical examinations, bloodwork and X-rays of 15 critically endangered sea turtles.

The Kemp’s ridley turtles have a guarded but good prognosis after a month of medical treatment at the aquarium for injuries and illness they sustained as a result of a mass cold-stunning event in Massachusetts in early December.

Sarah Callan, Animal Rescue Program manager, said the 3- to 5-year-old juvenile turtles were initially rescued by the National Marine Life Center in Buzzard’s Bay, Mass., and spent several days being stabilized before 16 were initially transferred to the aquarium for longer term care and rehabilitation.

Cold-stunning in turtles happens when water temperatures drop, and the body temperature of the cold-blooded turtles, normally in the 70s, drops as well.

“They go into a hypothermic state when they strand, so their circulation slows down, respiration, heart rate, and they’re just floating lifelessly. Their body temperature when they initially stranded was in the 50s, which is really low, so it kind of puts their system in a state of shock,” Callan said.

She explained that the Massachusetts organization triaged the animals and slowly raised their body temperatures over the course of several days, to keep the turtles from going into shock, before they were stable enough to be transferred to the aquarium’.

Callan said it can take between two and three weeks before the effects of cold-stunning become apparent. Today, the turtles in their care are receiving individualized treatment for a variety of issues including malnourishment, systemic illnesses like pneumonia and bruising to the softer underside of their shells which can take months to heal.

Though one of the turtles transferred to the aquarium did not survive, Callan said they are cautiously optimistic about the futures of the remaining 15, who undergo weekly bloodwork and X-rays to monitor their health and progress.

She said that this week, the turtles’ scheduled bloodwork was changed to every other week, a very good sign.

Though Kemp’s ridley sea turtles can be found from the Gulf of Mexico to Nova Scotia, they primarily nest in just one area of northeastern Mexico, just south of the United States border.

Averaging 100 pounds at adulthood, they are the smallest and, due to human impact, most endangered sea turtle in the world.

Though regulations have helped, Kemp’s ridley eggs were once extensively harvested for human consumption, and many turtles also die after swallowing fishing hooks or being caught in fishing nets and traps. Others drown after getting tangled in fishing lines or garbage, like the plastic rings that hold six-packs of cans together.

Development in their coastal breeding area threatens nesting areas, and the artificial lights deters females from coming ashore to lay their eggs as well as confusing hatchlings trying to make their way to the water.

While the turtles’ critically endangered status has historically been primarily driven by humans, climate change has become an increasing threat. Rising sea levels threaten nesting grounds and temperature fluctuations impact the turtles’ migratory patterns, breeding cycle and food sources.

Callan explained that conservation is essential to the species that takes approximately 15 years to reach maturity and begin to breed, as are the aquarium’s efforts to nurse the turtles back to health so they can be released.

She said the turtles still have a couple months of recovery ahead before they are healthy enough to be released, but soon rescue program staff will begin monitoring water temperatures at sites in Florida, North Carolina and Delaware to determine the best location to release the turtles.