Indiana State University Newsroom

Wabashiki turtle research holds promise

August 14, 2015

An effort to protect turtles crossing one of Terre Haute's busiest roads may lead to research that helps protect humans.

A group of residents has been working to save turtles crossing U.S. 150 near the Wabashiki Fish and Wildlife Area. Realizing valuable blood samples could be collected from these animals, Indiana State University doctoral biology student Ryan Seddon teamed up with them.

"As biologists, the first challenge is getting your animal," said Diana Hews, Indiana State biology professor and interim department chair.

Their efforts looking at the stress hormones and health of the red-eared slider are just in the beginning stages of building a dataset, which can be used to apply for more grants, but this research holds promise for countless other projects, including studying endocrine disruption markers.

"That would be very important to know for people eating fish out of the Wabashiki," Hews said.
The Wabashiki Fish and Wildlife Area, which includes 2,400 acres along the west bank of the Wabash River between Terre Haute and West Terre Haute, opened to the public in August 2010.

"Marshes are known for being able to clean up water and things like that. Potentially, it would be useful to know if we can show certain remediation practices, such as letting the marsh grow back, leads to improvement in the dysfunction we're finding," she said. "It's a longer-term approach. We thought it'd be kind of neat to get in there on the front end and document the current status of the animals and then follow them as presumably as the water gets cleaned up."

The earth and environmental systems department at Indiana State has been testing for heavy metal contamination in locations near the Wabashiki -- a database of soil samples Hews said she'd like to tap.

"There are a growing number of studies showing the kind of environment you grew up as a kid -- including in humans -- influences the set point of your adrenal gland and your responsiveness as an adult to stressors and how much hormone you release," she said.

Assisted by undergraduate Rodney Lockman, Seddon's analysis focused on the hetrophil-lymphocyte ratio, a measurement of white blood cells, and corticosterone, comparing turtles found along U.S. 150 and at a lake located in an apartment complex near Indiana 46, about a mile from Terre Haute's east side Walmart.

He discovered the lake turtles have a higher hetrophil-lymphocyte ratio than the road turtles, but the highway turtles have an elevated stress hormone compared to those at the lake.

"There is a difference between the stationary lake turtles and the road ones. It could be because (the road turtles) are moving," he said. "Corticosterone releases energy into your blood. You need the energy to move."

Known as a stress hormone, corticosterone mobilizes glucose in the body.

"A short-term high is adaptive. It's good. The hormone is there for a reason," Hews said. "You might not even call that stress -- their glucose is up, their cort levels are up, because they're walking across the road."

If it's chronically high, though, that's a different situation.

"We'd need to look at stationary ones within the Wabashiki to see if they have a similar response. We're just looking at those mobile ones, so it's hard to tell how much is attributed to moving across the road versus environmental conditions," Seddon said. "It is a little higher than you'd expect for a turtle just sitting there."

The researchers are hoping to add more types of sites, including reclaimed strip mines, and maybe expanding their study to other animals, such as fish. Turtles are long-lived creatures, so even if there's an improvement in the environment, their longevity could inhibit seeing much of a change biologically.

"If we have any changes in the next five or 10 years, a lot of these (turtles) are already too old (to see a change). They've already been affected," Seddon said.

The Wabashiki itself offers different kinds of sites to test, but they'll need permission to conduct research in the area, and any turtle traps they set will need regular monitoring.

Seddon and Hews aren't the only ones looking toward the future. This past winter, the group of turtle enthusiasts was successful in getting "Turtle Crossing" signs erected along U.S. 150, and now they're lobbying to create an eco-tunnel for the animals. Plans created by Rose-Hulman Institute of Technology students call for a tunnel that runs under the highway so the turtles can safely cross and a fence to keep them off the roadway.

"It would be pretty effective, so we could save a lot of turtles," Seddon said.


Photos: -- Indiana State University student Rodney Lockman walks along a roadway while conducting turtle research. -- A young red-eared slider turtle is seen. Indiana State University researchers are in the beginning stages of building a dataset from the species and are hoping to apply for more grants to further their research.

Contact: Diana Hews, biology professor and interim department chair, Indiana State University, 812-237-8352 or

Writer: Libby Roerig, media relations assistant director, Office of Communications and Marketing, Indiana State University, 812-237-3790 or