All the Light We Cannot See

Undergraduates at the UNC Outer Banks Field Site study how artificial light at night affects wildlife and share their results with community members.

January 18th, 2024

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On a moonless night, Kenza Hessini-Arandel treks across the beach toward the shoreline. She pulls a device the size of a garage door opener out of her backpack and thrusts it into the air. A number flickers across its digital display. After writing it down in her notebook, she packs up her things and heads to the next field site.

“Whenever we’ve gone out there, the waves are crashing, and you can hear them but you can’t see them,” says Hessini-Arandel, a junior at UNC-Chapel Hill. “And there’s crabs running around everywhere. So, it’s a bit of a process going out there and taking these measurements in the pitch black.”

In Fall 2023, Hessini-Arandel was one of 12 undergraduate students studying coastal science and environmental policy at the UNC Outer Banks Field Site (OBXFS) on Roanoke Island. During the semester-long program, students complete a capstone research project. Last semester, they studied changes in artificial light, its effects on sea turtle nesting, community perception, and support for reduction measures.

Light pollution disrupts the natural cues of day and night, which can confuse circadian rhythms and negatively affect sleep patterns in nearly all living organisms, including humans. It can also affect growth and flowering patterns for trees and plants and can lead to changes in behavior, foraging, and breeding among insects, turtles, birds, fish, reptiles, and other species. Artificial light is especially disorienting during migration. In October 2023, a building in Chicago killed nearly 1,000 birds in one night.

“The Outer Banks are really developed in a lot of places and that comes with lots of artificial light at night,” says Hessini-Arandel. “It’s important that we understand how it’s impacting things, especially turtles — a lot of which are endangered — to better understand how we can manage our development on the coast.”

Collecting the data

To measure light pollution along the islands, students traveled to 14 beach access sites from Corolla to Oregon Inlet at three different times throughout the semester. They took readings during new moons and recorded visible light sources, constellations, and cloud coverage, which can reflect light and impact measurements.

During the day, they compared their measurements to previously collected satellite data to understand how artificial light at night is changing along the islands. They also analyzed sea turtle nesting data to determine how light levels impact nesting behavior.

“Certain levels of artificial light can harm us or other organisms like sea turtles,” Carolina junior Nijah Pope explains. “And it’s something that people aren’t aware of unless they see evidence showing that the light from their beach house can disrupt sea turtle habitats and cause them not to be able to lay eggs successfully.”

Additionally, students surveyed residents and visitors to learn about their perceptions of artificial light at night and what they might be willing to do to reduce it.

Creating good stewards

During the summer, OBXFS Director Lindsay Dubbs and Associate Director Linda D’Anna spend a lot of time brainstorming topics for the fall capstone project. Once they pick one, they have an idea of the methods students will use, but they can’t predict their results.

“It’s original research, so we don’t know the answers — and we don’t necessarily know how it’s going to go,” D’Anna says.

Students take classes on coastal science and environmental policy and apply that knowledge to their projects. They learn how to pose research questions, formulate hypotheses, collect and analyze data, and present their results to the community.

“The students get thrown right into it from the first day they are here,” Dubbs shares. “We have discussions with them weekly about what they want to do and how they will collect and analyze their data. And they take control of it.”

At the end of the semester, they compile their data into a digestible presentation for community members and engage in meaningful discussions about how to protect the people and ecosystems of the Outer Banks.

“I see the Outer Banks as a place where students can learn to be stewards of their environment, and also the community around them,” Dubbs says. “The tools that we teach and the way that we teach students to be observant of their surroundings helps them to become stewards elsewhere when they leave this place.”

Kenza Hessini-Arandel is a junior majoring in environmental studies and minoring in Hispanic studies and marine sciences within the UNC College of Arts and Sciences.

Nijah Pope is a junior majoring in environmental studies within the UNC College of Arts and Sciences.

Lindsay Dubbs is the director of the Outer Banks Field Site and a research associate professor within the UNC Institute for the Environment. She is also the associate director of the North Carolina Renewable Ocean Energy Program and the Atlantic Marine Energy Center within the Coastal Studies Institute at East Carolina University.

Linda D’Anna is the associate director of the Outer Banks Field Site and a lecturer within the UNC Institute for the Environment. She is also a research associate within the Coastal Studies Institute at East Carolina University.