Don't Fear the Turtle

Although Kristen Hart has spent eight years studying and working at Duke, she still roots for the terrapins.

But that's not because the 30-year-old Duke doctoral student has any particular allegiance to the University of Maryland. It's because Hart has spent much of the past decade studying the diamondback terrapins, brackish water turtles along the Atlantic and Gulf coasts that face growing environmental threats from commercial fisheries and coastal land development.

A research scientist graduating from Duke this week with a Ph. D. in ecology from the Nicholas School, Hart worked out of the Duke Marine Lab in Beaufort for the last few years. She explored the terrapin's marine habitats from Cape Cod to Texas, with a focus on North Carolina and Florida. The U.S. Geological Survey (USGS) has partly funded her work.

In her research, which dates back to her undergraduate days as a biology major at Boston College, Hart has redefined the population structure of the terrapins, determined their home range and seasonal movement and identified at least six regional "metapopulations" (or subgroups) within the species. She has also calculated the first survival rates for adult mangrove turtles, which, although not considered endangered by the federal government, are at risk of becoming so.

"It was an obvious applied ecological research project," she said. She noted that terrapins are "a really good sort of model species to work with" because they face both land-based and sea-based threats to their existence.

Hart has also worked with commercial crab fisheries to cut down on the accidental killing of terrapins. She designed and conducted two studies with North Carolina commercial crabbers to understand why crab pots catch terrapins as well. In these two studies, supported by the North Carolina Sea Grant's Fishery Resource Grant program, she and the crabbers tested the ability of various bycatch reduction devices (BRDs) to reduce the catch rates of terrapins without interfering with the catch of valuable blue crabs.

"We've made strides forward," she said. For instance, researchers found that the terrapins suffer the most in April and May when the peeler crab fisheries are working intensively and the young turtles first emerge in the mud to eat and mate.

However, Hart said, more work still needs to be done. She noted that research studies show that adult male terrapins, which tend to be much smaller than adult females, slip through the excluder devices more frequently. The loss of the males appears to hurt the species' overall gene flow more than the loss of the females.

"We do see a skewing of sex ratios toward more females here," she said. "I'd like to see a shift towards figuring out what's going on with the males."

A native of Poughkeepsie, N.Y., where she helped raise pigs on a friend's farm while growing up, Hart said she has always been "an outdoorsy person." Although she originally planned to major in French in college, she quickly switched to biology in her sophomore year after she took her first science survey course.

"I discovered this whole track of research biology and I fell in love with animal behavior," she said. "It opened up a real field. No one in my family is into the sciences. Nobody had shown me this path before."

Now that she's completed her Duke studies, Hart plans to work in the Florida Everglades on a new research project. With funding from the U.S. Fish and Wildlife Service, she will conduct ecological and genetic studies of the juvenile green sea turtle, a threatened species entitled to federal protection.

Hart is further evidence of the trend in Duke's GraduateSchool to have students work across disciplinary boundaries. She holds a master's degree in environmental management from Duke and also did work in conservation genetics here. She said she wants to continue her terrapin research as well if she can gain the funding. But first she will take a long overdue vacation to Australia and New Zealand.

"I don't plan on getting any other degrees," she said. "It's definitely not anti-climactic."