56 sea turtles wash ashore on Cape Cod; experts blame cold

Three cold-stunned sea turtles get their first supervised swim at the New England Aquarium’s sea turtle hospital.New England Aquarium

Fifty-six endangered Kemp’s ridley and green sea turtles washed ashore in Wellfleet overnight and were rushed to the New England Aquarium’s Animal Care Center in Quincy, the aquarium said Thursday in a statement.

The turtles were hypothermic when they were rescued, the release said, and more sea turtles “are expected to come in through Friday with snow and colder temperatures continuing this evening.”

Kemp’s ridley sea turtles are “one of the smallest of the sea turtles, with adults reaching about 2 feet in length and weighing up to about 100 pounds,” according to the US Fish & Wildlife Service.

The green sea turtle can “reach three to four feet in length and weigh upward of 300 to 350 pounds,” the National Wildlife Federation says.

The dramatic overnight rescue followed a busy October, when Massachusetts Audubon volunteers saved 40 turtles on the Cape and transferred them to the aquarium’s Quincy facility, according to the statement.

“Additionally, two leatherback sea turtles that stranded on Cape beaches died within the last two weeks,” the release said. “Since 2005, there have been only five leatherback strandings in the region — so two in two weeks is unprecedented.”

Connie Merigo, director of the aquarium’s rescue and rehabilitation program, weighed in on the recent spike in shelled strandings.

“The sharp increase in sea turtle strandings last night and today are due to the plummeting temperatures and the onshore winds,” Merigo said in the statement. This has become more common for us to see these types of high numbers associated with strong on-shore winds. What is different is the number of cold stunned turtles stranding in October. We don’t know why this happened and at this point, I won’t speculate. Our focus now is on saving these turtles, so our work is entirely clinical in providing emergency care, slow warming, replacement fluids to help rehydrate the turtles, and nutrition.”

Vikki Spruill, president and CEO of the aquarium, said in the release that her staff is laser-focused on treating turtles in need of medical assistance.

“The New England Aquarium’s sea turtle and marine mammal rescue team has been at the forefront of treating thousands of endangered sea turtles year after year,” Spruill said. “We’ve had an unusual amount of mortalities with two leatherbacks in the last two weeks. Now, as the temperatures decline in late autumn, we are receiving a large number of sea turtles coming in for medical care and rehabilitation. As we treat these animals, we are also working on conservation measures for these threatened and endangered animals in their natural habitat.”

The Globe reported Wednesday that the cause of death for one turtle, a 286-pound juvenile that was critically ill and hypothermic when it was found Sunday, hadn’t yet been determined. It died Tuesday after “extensive treatment” by the aquarium’s staff, according to a prior release from the group.

On Halloween, a 420-pound female leatherback was found stranded in Brewster and died following treatment in Quincy.

For that turtle, the cause of death was determined to be complications related to a severe injury from entanglement as well as plastics that were found in its stomach, according to the aquarium.

Entanglements and boat strikes, particularly in the summer and fall, are common causes of death for leatherbacks, according to the aquarium, while plastic ingestion is becoming increasingly problematic for the species.

During the last 13 years, at least 220 endangered leatherbacks have been entangled in marine ropes along the Massachusetts coast, according to the aquarium.