Leaving in the morning to set nets

This could save endangered sea turtles

How one professor and her students are addressing the global problem of bycatch

For many years, scientists were skeptical that sea turtles could hear sound. They’ve since discovered sea turtles hear lower frequencies of sound than other animals, such as marine mammals. But why should it matter?

You’ve most likely heard about dolphins getting caught in nets meant for capturing commercial fish such as tuna and flounder, but it happens to other marine life as well, including turtles—many species of which are already endangered. Bycatch refers to any fish or marine species that is caught by accident in fishing gear.

An effective solution to preventing sea turtle bycatch, coincidentally, might just lie in using sound, which is where the work of Environmental Studies Assistant Prof. Wendy Dow Piniak ’03 begins.

A Gettysburg alumna who majored in Environmental Studies and Biology, Piniak pursued a master’s in Coastal Environmental Management at Duke University to learn more about the interdisciplinary nature of interactions between humans and the marine environment. Her master’s work focused on seals and their use of haul-out habitats (areas where seals leave the water to rest or forage on land or ice) in the Gulf of Maine, where she grew up.

After completing her degree, she was hired by the Wider Caribbean Sea Turtle Conservation Network to complete similar research, but on turtles, pinpointing their nesting sites in the Caribbean.

While completing this work, Piniak became interested in sensory ecology and how organisms in marine systems perceive and respond to the environment around them. “I was very interested in how sea turtles use environmental cues,” she said. “Around the same time, discussions of the potential for sounds produced by naval sonar or seismic oil and gas exploration to impact marine mammals were often highlighted in the news. I wondered, what about other marine wildlife? I learned quickly that we knew very little about marine turtles and sound. Many thought they were deaf or heard very poorly.”

So she pursued that research as the focus of a Ph.D. in Marine Science and Conservation in the Nicholas School of the Environment at Duke, investigating how sea turtles hear and behave in response to sound in the marine environment. That work helped add to a body of research, illustrating that sea turtles hear best at low frequencies and respond behaviorally to sounds in their environment. Knowing that could potentially save them from becoming bycatch.

Fisheries and fishermen commonly use gillnets, which are made of fine fishing line that’s often clear or green and very hard to see. Scientists have been successful in implementing strategies using light and other sensory cues to divert marine life from these nets, but Piniak said sound is an exciting area of focus because it is a sensory cue that can travel long distances in the water.

“The idea is to see if we can modify or add something to a net that will alarm or cue a turtle to its presence—without also alarming or scaring away the net’s target catch,” Piniak said.

Preparing acoustic deterrent devices

Piniak and team use acoustic deterrent devices that produce low-frequency sounds in an effort to deter sea turtles from fishing nets.

In collaboration with The Ocean Discovery Institute and National Marine Fisheries Service (NMFS), Piniak is focusing her research efforts in Baja California, Mexico, one of many areas globally where small gillnet fisheries interact with local populations of sea turtles.  With this team, she’s conducted fieldwork in Mexico over the course of three summers—the first year building an acoustic deterrent device that could emit a low enough frequency for sea turtles to hear, and the last two summers collecting data to determine whether or not turtles are being diverted from tangle nets equipped with sound (they are). Piniak says they plan to test these devices in fisheries next summer.

“It’s a very collaborative research environment including high school students, staff, researchers, and college students,” she said. “This project would not be possible without our partners. We conduct research from Ocean Discovery Institute’s field station and in collaboration with local fishermen. The research is supported by the National Marine Fisheries Service and other public and private contributors.”

The NMFS is a government agency responsible for the stewardship of the nation’s ocean resources and their habitat, and The Ocean Discovery Institute provides underserved students from San Diego, California, with scientific research and environmental stewardship experiences that enable them to pursue these fields in college and in their future careers. The past two summers, Piniak has also brought Gettysburg students along to help with the project.

“This is a great opportunity for our Gettysburg students. They’ve been able to participate in international field research and collaborate with other students and researchers, even helping to lead discussions with students about bycatch issues,” she said. “The high school and college students we work with from San Diego are learning to see themselves as scientists. That’s been one of my favorite aspects of the project—getting to interact with and mentor these inspiring students.”

Piniak with fellow researcher, Antonio Figueroa

Piniak with fellow researcher, Antonio Figueroa who participated in the Ocean Discovery Institute as a high school and college student and has since graduated from the University of California, Los Angeles and returned as a Fellow to help lead field research.

Piniak found her first mentors in Gettysburg and has now come full circle, becoming one herself. An educator at heart, teaching is what made pursuing a Ph.D. the right path for her, Piniak said.

“I knew I wanted a job like my advisor’s at Gettysburg.”

Piniak’s advisor was John Commito, affectionately called “Doc” by students, who has since retired.

“Even ten years after graduation, I was still talking with John Commito. He has been an invaluable mentor,” she said. “As professors, we keep in touch with the students who did research and studied with us. It’s one of the most rewarding parts of our work.”

Prof. Wendy Piniak

In collaboration with scientists from the University of Exeter, Piniak recently published a paper about marine air gun noise and its effect on turtles.


Founded in 1832, Gettysburg College is a highly selective four-year residential college of liberal arts and sciences with a strong academic tradition. Alumni include Rhodes Scholars, a Nobel laureate, and other distinguished scholars. The college enrolls 2,600 undergraduate students and is located on a 200-acre campus adjacent to the Gettysburg National Military Park in Pennsylvania.

Contact: Carina Sitkus, senior assistant director of communications, 717.337.6803

Posted: Mon, 14 Dec 2015

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