Rehabilitated sea turtles from New England Aquarium surviving years after release back into the ocean

BOSTON, MASS. (March 4, 2025) – Loggerhead sea turtles that were rehabilitated at the New England Aquarium and released back into the ocean in 2021 and 2022 are still alive and showing a surprising affinity for New England habitats, according to data transmitted from surgically implanted acoustic tags. This research fills a critical data gap on the survival and movements of rehabilitated sea turtles over several years.

*PHOTOS AND VIDEO AVAILABLE HERE WITH CREDIT TO NEW ENGLAND AQUARIUM*

The New England Aquarium has been engaged in sea turtle rescue, rehabilitation, and research for more than 30 years. Its Sea Turtle Hospital in Quincy, MA, is a world-class facility that has successfully rehabilitated thousands of sea turtles and returned them to the ocean. In 2021, Aquarium scientists and veterinarians were granted a federal permit to surgically implant acoustic transmitters in loggerhead sea turtles that had been successfully rehabilitated after stranding in Massachusetts. The internal transmitters can last for three to seven years, providing valuable long-term information on where the turtles swim, feed, and travel.

While satellite tag data has shown that the vast majority of the Aquarium’s turtles are surviving in the wild and exhibiting behavior typical of their species, the data has been time-limited to around six months to a year. The latest data from the loggerhead sea turtles that were acoustic tagged in 2021 and 2022 shows that the turtles are not only still alive, but some have returned annually to feeding habitats along the East Coast, including Massachusetts.

“These acoustic transmitters are telling us that rehabilitated sea turtles can survive beyond that first year, and they are showing up in well-established feeding areas. That gives us confidence in their ability to reintegrate into the wild population,” said Dr. Kara Dodge, research scientist in the Aquarium’s Anderson Cabot Center for Ocean Life. “We’re also finding that some turtles are returning to New England waters in the summer and fall, which was surprising and tells us this area may be more important for loggerheads than we previously thought.”

Researchers use acoustic telemetry to collect information about the movements of ocean animals. The transmitters are electronic tags that broadcast a series of “pings” into the surrounding water. These transmitters ping listening stations like an E-ZPass system when an animal passes by. Surgically implanted acoustic tags are valuable because of their longevity and inability to be shed. Almost all externally attached devices on turtles, such as satellite tags, are shed before they reach their full battery life—sometimes just days or weeks.

“It’s a little like Christmas morning every time we receive a new set of data,” said Dr. Charles Innis, a senior scientist and veterinarian at the Aquarium who pioneered the internal acoustic tagging procedure for sea turtles.

To date, acoustic receivers from Massachusetts down to Florida have detected the released turtles almost 6,000 times. The latest data showed many of the acoustic tagged loggerheads are returning to New England waters—Cape Cod in particular—one year and even two years later.

Dr. Dodge and Dr. Innis are now interested in learning if Kemp’s ridley and green sea turtles are also returning to New England or if this behavior is specific to loggerheads. Historically, state and federal regulators seek out data on sea turtle habitat use for proactive ocean planning and management around human activities in the ocean.

“If we continue to gather data for larger numbers of turtles in New England waters, we will likely have a better understanding of when they are typically present and where they spend their time, both of which may inform future protective measures,” Dr. Innis said.

“We’re helping build a knowledge base about sea turtles off the New England coast, which ultimately can help establish effective conservation policies,” said Dr. Dodge.

The team is expecting to receive data from some of the transmitters through 2032. As they continue their work, the scientists are seeking permission to use the acoustic tagging method on other turtle species, which could provide important information on these aquatic species that are rarely seen and poorly understood.

MEDIA CONTACT: Pam Bechtold Snyder—617-686-5068; psnyder@neaq.org