Turtles glide through the blue-green waters of Hornsby Spring like hockey puck slapshots as snorkelers stretch like goalies in their wake.
If the brownish-yellow blurs make it behind a cypress root or into a hidey-hole, swimmers are to “tip your cap and say ‘well done,’” researchers reminded them this morning. But not even a minute after diving in, one snorkeler gets lucky.
With a firm, two-handed grasp, he scoops an algae-coated turtle out of the water and into the warm March air. There, through ears covered by skin and scales, the turtle hears something unusual: a muffled Sunday sermon.
This spring and the river it feeds is a globally recognized turtle hotspot. Eleven freshwater turtle species mingle in its depths, a level of diversity seen in only a handful of rivers worldwide.
But locals know Hornsby better as the swimming hole for Camp Kulaqua: a Seventh Day Adventist retreat. As parishioners gather on a porch by the spring, guitar chords, scripture and singing ring out over the water.
Santa Fe College professor Dr. Jerry Johnston has studied turtles at the camp since 2008 and in the rest of the Santa Fe River even before that. His Santa Fe River Turtle Project, a collaboration among students, scientists and citizens, dove into its 23rd year at Sunday’s survey.
While the camp and other neighbors along the river cherish the turtles, development pressures in growing north central Florida increasingly pump out water from their habitat and return it laced with fertilizers and herbicides. By catching, tagging and measuring thousands of the marble-eyed river dwellers, Johnston examines how turtles respond to these changes and trains the next generation of their protectors.
Young and old
Jamie Saballos, 19, squeals as she carefully plucks a walnut-sized turtle from a snorkeler's hands. “Oh, my God,” she says. “This is the happiest I’ve been in my life.”
She sets it down in a black storage bin lined with an inch of water, then turns back to receive the next turtle. Over the course of an hour, volunteers fill dozens of bins with long-necked stinkpots, wide-eyed loggerhead musk turtles and watermelon-sized Suwannee cooters.
Rubber fins splash as a team of swimmers follows a canoe to search for more turtles downstream.
On land Henry Wang, 21, carries a bin of turtles uphill to a shady pavilion where they’ll be measured. “It’s a lot lighter than I thought it would be,” he says over the sound of turtle claws scratching at plastic.
About half of today’s volunteers are college-aged, many of them alumni or current students of Johnston’s biology classes. The rest are retirees, parents, researchers, neighbors and even one of the camp’s former lifeguards.
Sunday was many volunteers’ first time touching a turtle, a practice Florida law prohibits for protected species. But some have surveyed dozens of sites along the Santa Fe River for years.
Patricia “Trish” Eaton, a retired U.S. Air Force canine handler, is one of the old-timers. Decked out in a turtle shirt and necklace, she checks turtles for electronic ID tags as they arrive in the pavilion. She joined the crew after meeting Johnston in 2016.
“You get motivated to care about these turtles when you listen to him talk about how important it is to study these animals,” she says, flipping a turtle over so another volunteer can scan it for a tag. “I just keep coming back.”
The scanner beeps as if the turtle had a barcode. In a way, it does.
When Johnston catches and measures a turtle, he uses one of two methods to mark it.
The first is to cut small, painless notches in the turtle’s shell that correspond to a numerical key. But turtle fights and boat propellers can take out chunks of the animal’s shell, making them hard to identify.
The other way is to inject an electronic tag the size of a grain of rice under the turtle’s skin. Dr. Cody Godwin, an assistant professor at Santa Fe, demonstrates an unconventional technique he discovered as students look on.
Godwin holds a palm-sized musk turtle between his thumb and pointer finger, then slides its upper half into a teal beer koozie. The turtle kicks, but allows Godwin to insert the tag with a syringe and cover it with a skin protectant that looks like nail polish.
He measures every aspect of the turtle’s shell, then hands it to a volunteer to return to the spring.
Today’s baseline data are the turtle’s baby book. The next time researchers catch this turtle could be in the Ichetucknee River or a different Santa Fe spring. Like proud parents measuring a child’s height against the doorframe, they’ll document its growth.
Why it matters
Keeping tabs on thousands of turtles is more than a way to fill a bulging three-ring binder. It’s a means to measure ecosystem health.
The spring flow to the river has dropped an average of 20% compared to their historic levels since Johnston began tracking turtles in the Santa Fe River. The state has designated the Santa Fe River and its springs as “impaired” for high levels of nitrate and low levels of dissolved oxygen, conditions that coat parts of the waterway in slimy green algae. Regulators have set, missed, reset and started to make progress on goals to improve water quality.
Johnston has watched the turtles respond to it all through hundreds of surveys.
“You could just say, ‘Well why do you keep doing it? Don’t you already know?’” he said. “We still don’t have all the answers. We keep having questions.”
Sunday’s survey brought up a question – and maybe an answer – about a mystery born in 2012.
A historic drought baked rivers throughout Florida, reducing Hornsby Spring to a puddle by May. In June, Tropical Storm Debby dropped several feet of rain on the dry riverbeds. The Santa Fe River flooded, and facing enormous pressure from the water, the spring reversed.
Hornsby “was not a spring,” Johnston said. “It was like a toilet bowl.”
In the years that followed, Johnston went from catching about a dozen musk turtles each survey at Hornsby to catching none. Their numbers are just starting to return.
“The hypothesis for why it happened is the river got really low and so predators like raccoons probably had greater access to these turtles,” he said. That might’ve killed off enough of the population that it didn’t bounce back right when waters rose, Johnston thought. But, at the time, he didn’t have evidence.
Johnston’s team gathered live turtles, not empty shells that a predator would’ve left behind.
“We missed an opportunity,” he said.
Today, as an ongoing drought has again dropped Hornsby’s water levels low, volunteers looked for empty shells. They found four.
Johnston was wary of what that could mean for the musk turtles if the drought continues, but was jazzed at the finding. “This is support for that hypothesis,” he told the group. “All of you guys who helped to find the shells, it’s a big deal.”
Over the years, the survey has uncovered a lot of big deals.
Johnston has found that healthy springs can act as nurseries for baby turtles, adding an extra ecological reason – and a cuteness factor – for their protection. His team has documented the longest distance ever traveled by a freshwater turtle in North America: a 160-mile trek from the Santa Fe River to the mouth of the Suwannee and back.
Johnston said his proudest accomplishment is the people he’s trained.
More than 500 volunteers have learned how to handle turtles. Dozens have gone on to study them. Four have become ecologists. Beyond technical skills, Johnston shares a wonder for the animals, encouraging volunteers to look turtles in the eye, feel a female’s eggs and release them with utmost care.
If volunteers’ grins as they weigh, mark and measure the day’s last turtles are any indication, his passion has rubbed off.
