For decades, volunteers in Cape Cod Bay in Massachusetts have spent November and December trekking up and down the area’s beaches during high tide. They have a very important mission: finding stranded sea turtles that are so cold they can barely move, leaving them essentially defenseless on the shore.
The sea turtles that experience this are suffering from a form of hypothermia known as cold stunning. It can be caused when water temperatures rapidly decrease to below 10 degrees Celsius, and turtles are unable to move to warmer waters.
Unlike mammals, which can regulate their body temperature and are considered endotherms, most turtles, which are reptiles, are ectotherms. Ectothermic animals use the temperature of the environment they’re in to regulate their temperature. Turtles, for instance, rely on the temperature of the water or basking in the sun to stay warm. Cold-stunned turtles become lethargic, experience decreased circulation, and slowing of other body functions. Consequently, cold-stunned turtles are more likely to be hit by boats, eaten by predators, become sick, or die as their bodies shut down.
In Cape Cod Bay, though, these animals have passionate and caring human allies in Mass Audubon, a statewide conservation organisation, which uses staff and a volunteer corp to locate and rehabilitate stranded turtles in the area and then get them to safe warmer waters. These allies include Bob Prescott, who oversees the sea turtle program at the Mass Audubon Wellfleet Bay Wildlife Sanctuary, one of the approximately 50 sanctuaries that are part of Mass Audubon. Prescott is the sanctuary’s director emeritus.
Earther recently talked to Prescott, who is very busy this time of the year rescuing turtles, and asked him to walk us through what happens at the turtle stranding events at Cape Cod Bay.
Sea Turtles’ Human Allies
Prescott and the Wellfleet Bay Wildlife Sanctuary started saving cold-stunned turtles in 1982, a time when the Kemp’s ridley turtle was on the brink of extinction. It’s the smallest marine turtle of the seven species worldwide, with adults generally weighing about 100 pounds (45 kilograms) and reaching a length of between 60 to 70 centimetres. It is also the only sea turtle with an almost circular upper shell. Kemp’s ridley turtles are found primarily in the Gulf of Mexico, but they can also be found in the Atlantic Ocean as far north as Nova Scotia.
Over the last few decades though, the turtle has been in trouble. The worldwide annual nesting population nose-dived from 40,000 females in the 1940s to less than 300 females in the mid-1980s, according to the National Park Service. When Kemp’s ridley sea turtles started appearing cold-stunned in Cape Cod Bay, Prescott knew it was crucial to act.
“It really came down to [the fact that] every single individual was important,” Prescott said. “We think about 70% of the turtles that we see here on the Cape are females. We needed to save those turtles and make sure they got back into the Gulf of Mexico.”
Although Prescott and his team mainly save ridley sea turtles, they also find and rescue loggerhead turtles and green turtles. When the organisation started the program in the 1980s, Prescott said it rescued between 10 and 20 turtles per year, but now it averages about 600 turtles a year. As of today, the Kemp’s ridley sea turtle remains the most endangered sea turtle in the world.
The Challenges Turtles Face in Cape Cod Bay
Prescott explained that the turtles his team and volunteers find in the stranding events are juveniles, which are typically between two and seven years old that were born in the Gulf of Mexico area. They arrive in the waters off Cape Cod after getting caught up in the Gulf Stream, via the Florida Current, where they drift, swim, live, and thrive for one to three years as they are carried north. When the ridleys come ashore and start feeding in spring or summer, there’s no problem. The issues begin when fall approaches.
“They’re not picking up the cues that the days are getting shorter and that the waters are getting colder and that they have to leave,” Prescott said. That leads to a number of turtles getting caught in these cold-stunning events from November through January, he said.
The Kemp’s ridley sea turtles also face natural obstacles in Cape Cod Bay. The Cape is shaped like a hook, or a bent arm that extends out to sea, and it catches the turtles and slows them down while they try to figure out how to get out of there. Prescott said that there are more natural traps in Wellfleet Harbour and Provincetown Harbour, which also confuse the turtles and can keep them near Cape Cod when the water temperatures drop.
The Sad Reality of Cold-Stunning
It’s one thing to understand the science behind what happens to the stunned turtles, but stunned turtles can also end up in serious trouble. It’s heartbreaking and terrifying. When a turtle comes up to the surface, it can be overwhelmed by the waves and the wind, causing it to go back down underwater again. Turtles can hold their breath for three or four hours, Prescott said, but have to come up to breathe afterwards. When they come up to breathe, they’re pushed closer and closer to the shore.
“When they finally wash up, if we’re not there to pick them up, they would die,” Prescott said.
In fact, when people other than the sanctuary staff or volunteers find cold-stunned turtles, many think they’re dead. Prescott said it’s normal for an untrained person to believe that, because the turtles unfortunately really do look terrible. They’re usually covered in algae, exhibit zero behaviour, and take as few as one breath per minute.
Turtle Rescue and Recovery
Luckily, these turtles get help from Prescott, Mass Audubon staff, and volunteers, who receive specific turtle rescue training.
While wind and water temperature are the key enemies, the other key factor is high tide. There are two high tides in a day, one during the daytime and another one at night. That’s when the turtles usually wash up on the beach, blown there by the wind. During high tide, Mass Audubon volunteers walk up and down their assigned stretch of beach looking for turtles. Volunteers sometimes walk up and down the beach two or three times if it’s the start of a wind episode, Prescott said.
Once the group finds the turtles, the three-step process for recovery begins. The turtles that end up on the shore can sometimes have an alarmingly low internal body temperature of 4.4 to 10 degrees Celsius because that’s the temperature of the water they’re in. Prescott explained that staff and volunteers put them in a 12.7 degrees Celsius room and hold them there for between 12 and 24 hours. The goal is to get the turtles’ body temperature up to around 12 degrees Celsius. After they reach that temperature, the group sends them off to aquariums, Prescott said, where they’re put in incubators and further warmed slowly. All the while, the aquarium staff is stimulating the turtles by putting them in water, giving them medicine if needed, and moving them.
When turtles obtain a temperature of between 22.2 degrees to 23.9 degrees Celsius, aquarium staff ship them off to the south to 20 to 30 other aquariums who help the Kemp’s ridleys finish recovering. Flying the turtles to their next destination isn’t always a smooth ride, though. Prescott recalled a recent flight this year that saw 30 turtles rescued from Cape Cod Bay get stranded in Chattanooga, Tennessee, while on their way to their new home in New Orleans the night before Thanksgiving. Nonetheless, thanks to some last-minute help from the Tennessee Aquarium, the turtles were able to get to their destination safely.
In total, the recovery process can range from a few months to two years, Prescott said, adding that most turtles recover in six to nine months. After they recover, they are released into warm Atlantic waters or the Gulf of Mexico.
Rescue Operations During Covid-19
Few things in the world have remained unaffected by the covid-19 pandemic, and the Mass Audubon sea turtle program is no exception.
“Everything is way different than it was last year,” Prescott said. “It’s not affecting the turtles, it’s only affecting us [trying] to stay healthy, because if any of us get sick, then we’re out and there aren’t that many people involved in this.”
The turtle rescue operation relies on a network of people and organisations working together, and covid-19 has changed how it operates. The people involved are now always thinking about how socially distant they are from one another. Before, for instance, he said that Mass Audubon would have four or five people in the lab weighing, measuring, and boxing up the turtles for transport, yet now there’s only one person handling that work.
Nonetheless, Prescott stressed that covid-19 is not slowing down the group from rescuing turtles. As of Friday morning, the Mass Audubon sea turtle program had rescued 795 turtles.
Why Turtles Get Cold-Stunned at Cape Cod Bay
Why exactly the turtles are not leaving Cape Cod Bay in time and getting trapped in cold water is an open area of research. It could be that there is some genetic factor that’s not reading the environment right, or the fact that these are juvenile turtles and they lack experience. Climate change could also be a factor. The Gulf of Maine is one of the fastest-warming places on Earth. That’s made it an attractive feeding area for the turtles, but those same turtles don’t realise they might get trapped later on as winter sets in.
Any additional threat is one threat too many for the sea turtles, especially the endangered Kemp’s ridley. Though geography can trap them near the Cape and climate change may play a role, the biggest threat they face is another manmade menace.
“We [catch] them in shrimp nets, we poison them with the oil wells and all sorts of things like that,” Prescott said. “The Gulf of Mexico environment is deteriorating because of pollution.”
Hope for the Future
That doesn’t mean that humans can’t work to fix what threatens the Kemp’s ridley sea turtle, though. The federal government also has a plan to help bring the turtle’s back from the brink, including protecting nesting sites and habitat as well as collecting data to cut down on bycatch. Prescott’s team of workers and volunteers old and young and the network that helps return the turtle’s to safer environs will also continue their work.
“It really gives you hope for the future, that we could [save] a species that was on the edge of extinction,” Prescott said. “So many different universities and agencies and aquariums and people have worked so hard for decades to bring this turtle back and have been successful in doing that. This is a very important successful conservation story.”