Scientists created zombie 'Frankenturtles' to discover why loggerheads are dying

Researchers are hoping to find out where loggerhead turtles are encountering the numerous things that are killing them. Photo / iStock

The two majestic loggerhead sea turtles were dead, and nothing could change that. Like dozens of their kind, they'd succumbed in the ocean and washed up on Chesapeake Bay beaches, a major concern for marine biologists.

But two researchers had a crazy idea: What if they could bring the giants back to life, so to speak. David Kaplan, a professor at the College of William & Mary's Virginia Institute of Marine Science, and Bianca Santos, a graduate student there, went to work. They stuffed their body cavities with flotation material, stuck them back in the water and followed their drift in the hopes of finding where loggerheads are encountering the numerous things that are killing them.

The scientists didn't laugh madly. No electricity flashed between poles in a lab. But make no mistake, some horror was involved. "It's gruesome," said Santos. "It's not the prettiest of topics. But overall it's been positive."

They call them Frankenturtles because they look like monsters -- zombies with eyes missing and mouths shut tight. Their bodies at launch were still thawing out from the freezer at the Virginia Aquarium's Stranding Response Program, which collected the two specimens after beachcombers spotted them. Two weeks later, the mission to give their lives purpose is going "pretty well," Santos said.

Loggerheads are common in the Chesapeake Bay, with up to 10,000 appearing in its waters each summer to feed. But the bay isn't an easy destination for them. Loggerheads encounter numerous threats across their range and in the bay itself - accidental capture by anglers, entrapment in plastic junk, boat propeller strikes and sudden drops in temperature. Animals also prey greedily on turtle nests and tiny newly hatched loggerheads that die after going astray on their way to the ocean. Those threats collectively are why loggerheads are classified as a threatened species.

Between 200 and 400 a year washed up dead in the Chesapeake Bay region around the turn of the century, Kaplan said. Modifications to fishing nets have reduced that estimate to between 100 and 300 annually today, though scientists worry that the turtles they find are only a fraction of the overall shell count. "The actual number could be much higher," he said.

A Virginia Institute of Marine Science research team conducts a mock deployment of a Frankenturtle in the York River. Phto / David Malmquist, VIMS

Santos recently authored a decay study showing that turtles remain intact only for up to five days after death - with birds, crabs, and fish picking at them - and might disintegrate before drifting to a beach. Of those that get to shore, Kaplan said, "many probably strand in remote or marshy areas where they are unlikely to be observed and reported by a beachgoer."

The pair figured that if they could pinpoint where some of those threats occur most often, they could create loggerhead safety zones, at least in the bay. So they asked the response team at the aquarium for a dead turtle or two.

The hope was to use global positioning systems to track the floating animals and map where the winds and currents send them from a release point in the bay. "If our model can accurately simulate how winds and currents act on a dead sea turtle, we should be able to backtrack from a stranding site to the place where the turtle likely died," Santos said. "By knowing the 'where,'" she added, "we can better look at the 'why.'"

Before getting to those release points, the team had to create Frankenturtles. Two arrived frozen stiff from the aquarium. One was estimated to be about 20 years old, dead from a boat strike. The other was a juvenile, age not guessed and its death unknown.

VIMS graduate student Bianca Santos readies the wooden and Styrofoam turtle models for deployment into the Chesapeake Bay. Photo / David Malmquist, VIMS

The team removed the inner organs, which sounds disgusting but doesn't even begin to convey how wretched that task was. "In addition to the unforgettable and growing aroma of thawing turtle," David Malmquist, a marine science institute spokesman said, "the creatures are both heavy and unwieldy." The larger weighed in at 150 pounds, the smaller at 70 pounds.

The team replaced the organs with Styrofoam. "We cut up some buoys," Santos said, ". . .spread some foam, filled the bottom cavity with some foam stuff and some buoys." The first "actually took us a couple of hours to figure it out." The second was done in an hour.

"It might seem sort of gross, but it's a good way to reuse a dead turtle that would otherwise be buried," Kaplan said. "And hopefully, the deployment of our two Frankenturtles will ultimately help lower the number of turtle deaths in the future."

Four people were needed to carry them to a truck, unload them on boats and take them to deep water in mid-June. The researchers also built two wooden turtles to simulate drift and equipped those with a GPS. They did the same with a pair of drift buckets. They chose Mob Jack Bay as a release point between the York River and the Eastern Shore.

"They stayed on the surface of the water and drifted along," about five miles per day, Santos said. "The tracks are still working. We're hoping to release more, get some more data."