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Hands-On Science Puts Students In The River With Sliders And Soft Shells

A group of high school students has been diving into the world of soft-shells and sliders, and we’re not talking crab or tiny sandwiches. These kids are part of a lab class learning what field work is really like.

On a warm early October Sunday morning in Fort Worth, about a dozen students and researchers gathered by the Clear Fork branch of the Trinity River where it intersects with Rogers Road.

"We are doing the Trinity River turtle survey, which is a research project with my students at Paschal High School," explained Andrew Brinker, Paschal High School science teacher in Fort Worth ISD. "We come out once a month, catch turtles, mark them, measure them then release them back into the river."

Brinker got a grant from Texas Christian University to pay for the traps, scales, calipers and other survey supplies. He and his students are learning about the turtles here, from the red-eared slider to the razorback musk. They’re also studying how many are here and what they’re up to.

"But more importantly," Brinker said, "we’re trying to get students outside, actually doing research and science, instead of just reading about it or listening to classroom lectures."

Lectures, Brinker said, can be boring. But not this, said Paschal high senior Jake Harper.  

Paschal student Jake Harper
Credit Bill Zeeble / KERA News
Jake Harper's one of Andrew Brinker's science students at Paschal High School in Fort Worth. Brinker involves willing students in his Trinity River Turtle Survey monthly along the river.

"I kind of like the natural part of it." said Jake. "I like being outdoors. I’m more of a getting in the river and pulling out the turtles, than a measuring them kind of guy. It’s not for everyone, but it’s just a really cool project." 

The class prepares to pull up the last of the day's four hoop traps from the Trinity’s edge.  

"Bring her up." said Brinker.  "Oh there is one. It’s a snapping turtle. Yes! Awesome." 

Then it was time to weigh and measure the awesome, scary snapper. Ki Rendon got the honor. She’s an 8th grader – not a Paschal High student – but she’s been doing this for years on her own.

snapper turtle caught in a hoop net
Credit Bill Zeeble / KERA News
Ki Rendon holds the snapper caught in a hoop net, while others, including (to Ki's right) Olivia Castillo and Maya Seymore, help measure the turtle.

"My cousin lives on a pond," Ki said, "I go over there every other weekend and I catch turtles."  

Ki carefully weighed and measured the snapper, after putting a towel over its head so it couldn't find her finger.

"Fifteen," Ki said.

"And then post?" asked a colleague, who’s logging the numbers. "What is it?"

"Eighteen-point-nine," Ki said.

Not giant, not small. Brinker is usually the only one to handle snapping turtles because they are always dangerous, but Ki has experience. 

"Stay away from the half of the shell back in the front because its head can go all the way back there," Ki explained how to safely handle a snapping turtle. "So mainly you’ll usually grab the back two legs. You can put your hand right under its back legs and you can hold it that way … from the plastron."

The plastron is the turtle’s underside. An electronic reader wanded over it reveals this snapper has no tracking chip, so it gets one — injected under the shell which also gets notched. The spiny soft shell, also caught in the net, cannot safely have its shell notched,  so it gets chip then out comes the Inkinator — a portable, cordless tattoo gun.

The Trinity River Turtle Survey is approaching 1,000 turtles caught and released over two years. Brinker and his team of testudines geeks have also measured pollution in the river, mercury in the turtles and even the food in their stomachs.

This spiny soft shell female gets tattooed because an electronic tracking chip won't stay in this species.
Credit Bill Zeeble / KERA News
This spiny soft shell female gets tattooed because a notch in the shell won't work.

“We’ve already documented Asian clams in the river that they’re feeding on,” said Brinker. “So it’s kind of neat, an introduced species that these guys are eating. Asian clams have been introduced throughout all of Texas, and now we have zebra mussels in Lake Worth. Did these guys start feeding on them?”

So Brinker is now looking — as he and his students put it — at turtle turds. Researchers know some of the turtle species in the Trinity River do eat the destructive and wildly invasive zebra mussels.  

Brinker and several students recently exercised their own turtle muscles. They presented some of their river research at the fall symposium of the Texas Herpetological Society in far west Alpine, Texas. 

Updated 9:58 a.m.

Bill Zeeble has been a full-time reporter at KERA since 1992, covering everything from medicine to the Mavericks and education to environmental issues.