Travis Thomas grew up on the Santa Fe River, but never imagined he’d lean over its glassy waters and hoist up a 65-pound prehistoric beast.
The creature at hand was an alligator snapping turtle: spikey and iron-jawed. Santa Fe College professor and turtle aficionado Jerry Johnston had enticed 23-year-old Thomas, who has enamored with alligators, into fieldwork with the promise of an equally impressive reptile.
It was love at first (near) bite.
Two decades later, Thomas, now 44, is a research assistant professor at the University of Florida's Nature Coast Biological Station. Alongside Johnston, he’s a leading expert on alligator snapping turtles. In 2014, he led the team that identified the Suwannee alligator snapping turtle as a separate species. Last year, he was integral in securing the ancient animal’s protection under the Endangered Species Act.
A “recovery plan” for the snappers is expected this year. But a rule change proposed by the Trump administration last week could weaken their protections. Johnston, Thomas and their students continue their work undeterred, bringing together three generations of researchers to protect North America’s largest freshwater turtle.
A “red rocket” and a bathroom scale
Ask Johnston why he decided to study alligator snapping turtles and he’ll say it was “totally selfish.”
A New England native, he didn’t grow up in snapper country. But he’d heard stories of the turtles’ massive size and crushing bite, strong enough to break bone.
In 2004, Johnston and Thomas cobbled together field equipment and ventured to O’Leno State Park to survey the “almost mythical animals.”
Among their supplies were traps, a bathroom scale and a 13-foot, square-backed canoe with a motor borrowed from Thomas’ grandfather that failed just about as often as it worked. The pair called it the red rocket.
It took a few trips to find one of the shy creatures, but, when they did, Thomas stared in awe. “It was huge,” he said, “and had a super ancient-looking, gigantic head.” Tiny spikes around its black-spoked eyes acted as pressure sensors, detecting prey’s motion in the water. Thick claws extended from its webbed feet.
Thomas was hooked.
The team grew, gathering more volunteers and more sophisticated equipment. After a few years of field work, they began to notice something unusual.
The alligator snapping turtles in the Suwannee and Santa Fe Rivers didn’t look like the ones documented in the Panhandle and farther west.
Thomas, by then having moved on from Santa Fe College to the University of Florida, wrote his undergraduate honors thesis documenting the differences. He pursued his master’s while working alongside wildlife biologists at the Florida Fish and Wildlife Conservation Commission.
After comparing his colleagues’ observations to his own, “that's where I started thinking, ‘what if these have been isolated in the Suwannee and evolved a little bit differently?’” Thomas said.
Research on the animals’ bodies, genes and fossils confirmed his suspicions in 2014.
A unique species
Thomas and his colleagues compared the shells of more than 100 alligator snapping turtles from the field and from museum collections. They found a variety of differences, most notably that specimens from the Suwannee River had a crescent-shaped notch at the back of their shells while other alligator snapping turtles didn’t.
The team had identified a new species.
Thomas, the lead author on the 2014 study, named it Macrochelys suwanniensis, large turtle of the Suwannee.
Though the reason for the notch isn’t well understood, genetic analysis traced the divergence back around between five and 13 million years ago.
In that so-called “Age of Mammals,” an explosion of animals roamed Florida as sediments from the Appalachian Mountains stacked a sandy layer onto the peninsula’s carbonate base.
The Suwannee alligator snapping turtle fit right in among elephant-sized giant sloths and carnivorous bear-dogs. But while the latter two became extinct, the snappers survived virtually unchanged.
Today, they inhabit the black waters of the Suwannee River Basin, from the Okefenokee Swamp in Georgia to the river’s mouth in the Gulf.
The species’ limited range, coupled with water quality and quantity threats to its ecosystems, drove the nonprofit Center for Biological Diversity to take the U.S. Fish and Wildlife Service to court in 2016, urging legal protections. The agency spent eight years researching, surveying turtle populations and drafting a rule.
Victory came last summer.
The agency listed the Suwannee alligator snapping turtle as threatened under the Endangered Species Act and outlined extra protections banning the turtles’ export, shipping and transport.
“It's been a long time coming to win protection for a species that has really been beleaguered by many threats,” said Elise Bennett, the nonprofit’s Florida and Caribbean Director. “ The Act has been incredibly effective. It's prevented extinction for 99% of species that have been listed, and many of them are on track for recovery.”
The listing only applies to the Suwannee species of snappers, but protections for other alligator snapping turtles could be forthcoming. The agency proposed them for protection in 2021 and hasn’t yet issued a final decision.
When waters fall
Heavy, huge and hidden, adult alligator snappers have few natural predators.
Their bony shells are lined with three rows of peaks, meringue-like in shape but with rock-solid strength. It takes a bite force of a predator about 200 times a turtle’s size to crack the turtles’ armor but a hook about the size of a quarter to puncture their fleshy mouths, trapping them on fishing line.
One of the turtle's most common killers is being caught whether intentionally or accidentally.
The turtles chomp on static lines set to catch fish in rivers, perforating their digestive system or drowning them.
Poaching and commercial harvest for turtle soup decimated alligator snapping turtle populations in the 1960’s, especially in Georgia, Mississippi and Louisiana. Harvesters heaved a pickup truck’s weight worth of turtles from the Flint River each day, destined for the tables of luxury restaurants.
Since it takes decades for the snappers, which can live into their 40s, to reach sexual maturity, overfishing claimed whole generations.
Suwannee alligator snapping turtles were largely spared. There were no commercial harvesting operations in the Suwannee Basin. Florida limited recreational harvesting in the 1970’s and banned it entirely in 2006.
Habitat degradation is a bigger worry.
Flows in the Suwannee River have dramatically declined in the past 25 years as humans pump out water faster than the Floridan Aquifer can replenish it. Withdrawals lowered the Santa Fe River beneath its legal limit in 2015. It still hasn’t recovered.
When water levels drop, the shallow riverbanks in which snappers hide from predators are the first to go. That’s a challenge for young turtles whose ping-pong-ball-size and soft shells make them easy targets for raccoons, birds and other predators.
Low flows impact the turtles’ prey, too.
Suwannee alligator snapping turtles feast on the river’s entire buffet: fish, mussels, acorns, carrion, frogs, palmetto berries, snakes and even smaller turtles. They lay motionless on the river floor, use a bright pink, worm-like extension of their tongue to lure prey into their mouth, then snap down and swallow.
Low flows can harm the bottom of the food web by promoting algal growth and drying up the floodplains, channels and other alcoves that house much of the river’s diversity.
“It’s important to note each individual species that's in trouble and try to give them individual help, but I think this is also a real warning sign for us that we need to be doing more for our water quality now,” said Bennett, the nonprofit director. “Even our very best, most pristine ecosystems are not doing well.”
Protected, but not fully
When the FWS listed the Suwannee alligator snapping turtle as threatened, it made one controversial decision: not designating a critical habitat area.
Such areas provide legal restrictions against building or modifying the species’ habitat in any way that could harm it, something advocates say is particularly important in Florida given rapid development.
The agency hadn’t “determined the extent to which critical habitat may be prudent,” at the time of listing, partially due to the concern that it could alert poachers to the turtles’ locations.
Thomas called the reasoning “nonsensical”.
“Poachers already know where the turtles are,” he said. “Lot of the methods and the information that we had prior to the rush of alligator snapping turtle research over the past 20 years came from a guy named Al Redmond, who was the biggest poacher in alligator turtles’ history.”
Redmond said he realized his impact on the species and turned to breeding and re-releasing them in the 1980s. While not all poachers have had the late Redmond’s change of heart, Bennett argues the benefits of a critical habitat designation outweigh the risks.
“We were disappointed by this decision and, in fact, we submitted extensive comments explaining how the agency could go about protecting habitat without identifying specific locations of turtles.”
She pointed to the example of the rim rock crowned snake in South Florida: a tiny, black-headed snake proposed as endangered. The agency included a critical habitat for the species in its proposal even though the rarity of the species put it at risk of poaching by collectors.
“We've seen the agency do it and it suggests they could have done it again,” Bennett said.
Lacking a critical habitat designation, the Suwannee alligator snapping turtles are particularly vulnerable to a new regulatory change proposed by the Trump administration and open for public comment until May 19.
The revision would remove the definition of “harm,” which currently includes significant habitat degradation, from the Endangered Species Act. Listed species would still be protected from “take,” including hunting, harassing, trapping and other similar activities.
Advocates worry the modification could bring development into the animals’ feeding, sheltering or breeding grounds, chipping away at an Act long-heralded as one of the world’s most successful conservation efforts.
For the snappers, “it’s not only concerning that they didn't get this sort of blanket protection for their habitat,” Bennett said, “but now we're going to see continuing weakening of the law when really, they need the help of the law the most.”
The next generation
More than 500 volunteers have dived, paddled and waded in North Central Florida’s waters through the turtle survey efforts Johnston launched in 2004. His aptly named Santa Fe River Turtle Project has documented where musk turtles, snapping turtles, Suwannee cooters and others live, what they eat, how they move and how they’re withstanding environmental change.
Four of its participants, Thomas included, have become ecologists.
Last year, Thomas and Johnston returned to the Santa Fe River, two decades after they first met. They had traded the red rocket for a more dependable johnboat and the bathroom scale for a weighing net. But they were as excited as ever to glimpse the “mythical” creatures.
When the pair hoisted a snapper out of the water, they couldn’t believe their eyes.
It was turtle #1: the very same specimen they had caught on that first field expedition 20 years ago.
It was active, 20 pounds heavier and healthy: a reminder that as ecosystems and rules change, the turtles — and the researchers — hang on strong.
