Why the most endangered sea turtles in the world are getting stranded very far from home

On an October afternoon along the coast of the Bay of Fundy in Nova Scotia, a sea turtle rested on the sand. When local beachgoers walked by, they assumed the turtle was dead—until her eyes moved. 

“I honestly didn’t even think of there being sea turtles in these cold waters,” says Michelle Pope, who found the critically endangered sea turtle—later named Lucky. Lucky is a Kemp’s ridley, the most endangered sea turtle species in the world.

Believed to be female and about 3 to 5 years old, Lucky was one of nine cold-stunned sea turtles documented in Atlantic Canada during the 2025–2026 season. She was also the only one to survive.

In fact, it’s rare for sea turtles like a Kemp’s ridley to be that far north because they are native to the Gulf of Mexico and adapted to the tropics. But scientists say that across the North Atlantic, more sea turtles are being found cold-stunned—that is, critically incapacitated by cold water—as warming oceans shift migration patterns.

Each fall, juvenile sea turtles like Lucky are carried north by warming ocean currents and linger in seasonal feeding grounds along the northeastern Atlantic coast. As ectothermic animals, they rely on their environment to regulate body temperature; when waters drop below 50°F (10°C) or so, they become vulnerable to hypothermia, or “cold-stunning.” Their internal temperature plummets, muscles begin to fail, and heart rates slow. 

Too weak to swim or dive, they either drown or drift helplessly. Winds, waves, and powerful tidal systems such as those where Lucky was found in Nova Scotia can then carry them ashore. 

Strandings on the rise 

Once concentrated largely around Cape Cod, cold-stunning events are now being documented farther north—including in Atlantic Canada—as environmental factors like ocean warming draw turtles into increasingly risky waters.

(Hot water: How much are oceans warming?)

During the 2025–2026 cold-stun season, 771 cold-stunned turtles were documented across the northeastern and mid-Atlantic United States—and 80 percent of those were juvenile Kemp’s ridley turtles like Lucky.

Massachusetts has seen strandings rise from roughly 140 turtles annually two decades ago to more than 700 in recent years. And Atlantic Canada, where Lucky was found and where only one or two cold-stunned turtles were typically documented annually, has recorded higher recent totals, including 17 cases in 2023–2024 and nine in 2025–2026.

The rising frequency and scale of these cold-stunning events remain puzzling to researchers. “The changes over time in terms of the size of the events we’re having and the regularity is intriguing,” says Brian Stacy, a veterinary medical officer for the NOAA’s National Sea Turtle Program within the Office of Protected Resources. Even more baffling, he notes, is the turtles’ tendency to linger in shallow, trap-like coastal waters rather than heading for open ocean. “The idea that animals would select these types of places that are super risky—and not move offshore the way we think they normally should—is very perplexing.”

What is clear is that the trend is expected to continue. “We anticipate that this number is going to rise,” says Kathleen Martin, executive director of the Canadian Sea Turtle Network in Halifax, noting that turtles are increasingly found beyond their historical northern limit of Cape Cod. 

A mysterious journey

Why juvenile Kemp’s ridleys end up so far north—and why some become cold-stunned—are tough questions for scientists to answer. While warming seas and powerful currents act as an accidental highway pushing the turtles north, their navigational choices once they arrive remain a mystery. 

“As much as we know about sea turtles, it’s amazing how much we still don’t know,” says Margaret Lamont, a research biologist at the U.S. Geological Survey’s Wetland and Aquatic Research Center who has studied sea turtles for more than three decades. “We don’t really know why they’re up there, whether they are going there on purpose, or why they don’t leave.”

According to Stacy, one of the biggest unknowns involves the “lost years”—the period between when hatchling Kemp’s ridleys leave their nesting beaches in the south and when they reappear as juveniles in coastal feeding grounds up north. Biologists know these young turtles spend much of their development in the open ocean, where Stacy says powerful oceanographic conditions dictate their movements. But instead of migrating to their usual warm habitat in the Gulf, some of these juveniles mysteriously emerge from the open ocean much farther north than expected. 

Cold-stunning itself is equally complex. “Everything is linked, so we can’t look at one predictor or one variable as the driver of cold-stunning events,” says Lamont. While climate change is often discussed in relation to warming oceans, Lamont said a broad suite of factors, including large-scale weather systems and ocean currents, likely influence whether turtles become cold-stunned and stranded. 

Many people who encounter a cold-stunned sea turtle assume it’s best to return them to the water, but doing so can be fatal since they’re too weak to swim and must be warmed gradually. Fortunately, beachgoer Pope knew to call a rescue to help when she found Lucky. The Canadian Sea Turtle Network stepped in and rehydrated her, administered antibiotics, and gradually warmed her—critical first steps in stabilizing a turtle suffering from cold-stunning, though she wasn’t out of the woods. 

A race to save Lucky

Lucky’s initial care in Halifax made her stable enough to travel, though her prognosis was still uncertain. She was transported to the Atlantic Veterinary College at the University of Prince Edward Island, where she would begin a longer rehabilitation under Dr. Lara Cusack.

“She was skin and bones,” says Cusack. The young turtle was severely emaciated and her shell was covered in wounds and lesions; blood work confirmed a bacterial infection, which could have led to sepsis if Lucky hadn’t been treated promptly. “I expect that she would not have survived more than another day or two [had she not been found.]”

One of the biggest challenges was getting Lucky to eat; a refusal to take food is a clear sign of stress or a more serious issue. Little by little, though, she began to show an interest in mealtime. “As she got healthier, she got fussier,” Cusack says. Lucky initially favored squid before switching to shrimp, and Cusack found herself buying out the grocery store’s shrimp supply every two weeks.

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By late February, Lucky had nearly doubled her body weight; it was a critical shield. Cusack knew that if Lucky wasn’t at peak strength, the grueling journey south could easily prove fatal. But after months of specialized care, she became the first endangered Kemp’s ridley sea turtle to be successfully rehabilitated in Canada. So, armed with specialized life-support equipment—including heating blankets, laser thermometers, and industrial ocean salt to manufacture synthetic seawater on the fly—the team set out for Nassau, Bahamas. When a massive snowstorm in Halifax delayed their departure, that emergency salt saved the day, allowing the team to safely house Lucky in a hotel bathtub until weather conditions improved.

When travel resumed, Lucky flew in the aircraft cabin of a commercial flight, secured beneath a seat. When the plane touched down in the Bahamas, Lucky was stable but still highly vulnerable. She arrived at Atlantis Paradise Island’s veterinary facility, where veterinarian Deandra Delancey-Milfort and her team placed Lucky in quarantine and monitored her vital systems to ensure she had truly survived the deep freeze of Nova Scotia. The ultimate hurdle for release was making sure Lucky could dive and forage independently—if she remained marooned at the surface, she would be an easy target for boat strikes or predators like sharks.

In early April, after weeks of observation, Lucky was ready for release. The team transported her offshore to the deep, warm Bahamian waters.

“I think she could smell the ocean because she got noticeably excited, air swimming in her container on the boat,” said Delancey-Milfort. “Seeing her swim off felt bittersweet because you’re still wanting to be protective of your patient, but it was gratifying because that’s where she’s supposed to be.” 

Eyes on the shoreline

The last assessment of Kemp ridley’s sea turtles in 2019 suggested that there were around 22,000 left in the wild, though current populations are unknown. 

“With a population as critically endangered as Kemp’s, you don’t want to risk losing a thousand [to cold stunning],” said Lamont, questioning what the loss of 500 turtles every five years could mean for an already imperiled species. Lamont estimates that there may be fewer than 10,000 nesting females.

To better understand young turtles’ movements and why some like Lucky become stranded, researchers are increasingly combining tools that trace their journeys, according to Lamont. By pairing tracking tags that record real-time travel paths with DNA mapping that reveals a turtle’s birthplace, scientists can attempt to map out how ocean currents sweep these animals off course. 

But tracking juveniles remains challenging, as tags can become dislodged as shells grow. Stacy noted that much of what is known about the species comes from nesting beaches, where animals can be observed consistently. 

Pope, who found Lucky on the beach, says it had never occurred to her that sea turtles might be in Nova Scotia’s waters. But after discovering Lucky, she came to appreciate the importance of community in helping stranded turtles survive.

That begins with knowing who to call. Since 1997, the Canadian Sea Turtle Network has worked with coastal communities to coordinate responses to stranded sea turtles. Participation in its Sea Turtle Beach Patrol program has increased from 125 volunteers in 2024 to 637 volunteers across Atlantic Canada during the 2025–2026 season. 

Cold-stunning events often unfold during holidays, weekends, and severe weather, requiring responders to spend long days searching beaches, transporting animals, and supporting rehabilitation efforts. For Cusack, that growing engagement reflects something larger. “I worry that inaction is all too often fueled by a disconnect from the natural world,” she says. “A sea turtle isn’t a tangible thing to care about until someone realizes that one was found in their [own] backyard.” Even when that backyard happens to be a nearby beach.