Research

How Carolina is reducing its carbon footprint

The Institute of Marine Sciences buries carbon deposits in a salt marsh protected by oyster reefs.

Postdoctoral researcher Stacy Zhang walks along the shoreline measuring oyster density to understand how the oyster reef that protects a blue carbon saltmarsh habitat is growing. (Johnny Andrews/UNC-Chapel Hill)
Postdoctoral researcher Stacy Zhang walks along the shoreline measuring oyster density to understand how the oyster reef that protects a blue carbon salt marsh habitat is growing. (Johnny Andrews/UNC-Chapel Hill)

When it comes to helping in the fight against climate change, reducing your carbon footprint is a regularly suggested tactic — both for individuals and organizations.

Researchers at the UNC Institute of Marine Sciences are helping the University do just that with a blue carbon habitat in Morehead City. This human-made habitat collects and stores carbon dioxide from the atmosphere and serves as a carbon emission offset for Carolina, which is aiming to reach carbon neutrality by 2040.

Headed by Professor Antonio Rodriguez, the project involved the creation of a salt marsh with the intent of capturing carbon and depositing it into the marsh’s sediment along the shoreline near IMS. Initially created in 2014 with 3,500 bushels of shell and 2,000 bundles of marsh grass, the habitat has been tracked for the past seven years to gauge its impact.

Rodriguez is working with fellow IMS faculty members Michael Piehler, Joel Fodrie and several graduate students to collect sediment samples in the area to track carbon deposits and maintain the habitat by monitoring the rise in sea level to ensure the marsh’s protective oyster reefs continue to grow.

“When the call for proposals from the UNC Energy Services’ Climate Action Plan came out in 2012 to make campus more carbon neutral, we jumped at the chance to transform our shoreline into a more natural state,” Rodriguez said. “It ended up being a massive group effort with students, faculty and technicians working together, hauling oyster shells and planting marsh grass. The result has truly exceeded our expectations.”

Rodriguez and Piehler, a professor at IMS who also serves as the director of the UNC Institute for the Environment and Carolina’s chief sustainability officer, are working together on the project.

Rodriguez (left) and Piehler, a professor at IMS who also serves as the director of the UNC Institute for the Environment and Carolina’s chief sustainability officer, are working together on the project. Rodriguez proposed the $50,000 project to help the University achieve its carbon neutrality goals. The salt marshes, he said, can also serve as an educational tool for students, faculty and the surrounding communities.

Graduate research assistant Molly Bost collects sediment samples on the shoreline of the Institute of Marine Sciences on March 30, 2021, in Morehead City. Bost, who obtained her undergraduate and master's degrees from UNC, is currently a PhD candidate working on the shoreline restoration project with professors Antonio Rodriguez and Michael Piehler and associate professor Joel Fodre. According to the project team leaders, their goal is to create a new carbon offset for UNC through the creation of a saltmarsh and oyster-reef habitat near the IMS shorefront. They indicate that saltmarshes are “blue carbon” habitats which fix carbon dioxide in excess of respiration and bury carbon in sediments. The oyster-reef acts as a barrier, protecting the saltmarsh from waves and currents. Team leaders said their hope is for the project to serve as an enduring educational tool and demonstration of UNC’s broad vision in the ongoing efforts to achieve carbon neutrality. The IMS is an off-campus research laboratory, teaching, outreach, and service unit of the University of North Carolina at Chapel Hill. (Johnny Andrews/UNC-Chapel Hill)

Graduate research assistant and doctoral student Molly Bost, who earned her bachelor’s degree in environmental science and master’s degree in marine sciences at Carolina, collects sediment samples on the shoreline by IMS. The samples are later analyzed in the lab to examine how effectively carbon is being deposited in the salt marsh.

Salt marshes are “blue carbon” habitats that can store more carbon annually than terrestrial forests, playing a major role in mitigating climate change.

Postdoctoral researcher Stacy Zhang measures the size of oyster clusters on a nearby oyster reef.

Postdoctoral researcher Stacy Zhang measures the size of oyster clusters on a nearby oyster reef.

To protect the carbon-capturing salt marsh, IMS researchers constructed two oyster reefs. The reefs act as a natural barrier, protecting the salt marsh from currents and damaging waves from storms. Since oysters need a delicate balance of being exposed above water and covered by water to maximize growth potential, the team actively monitors the rise in sea level to ensure the reef continues to grow.

Zhang checks a fish trap at the saltmarsh and oyster reef habitat near the IMS shorefront.Zhang checks a fish trap at the salt marsh and oyster reef habitat near the IMS shorefront. While the human-made habitat could serve a role in addressing climate change through carbon sequestration, it also creates homes for various sea life, improves water quality and protects the shoreline from erosion.

Back in the IMS labs, Zhang examines a sediment sample to look for signs of an increase in carbon in the soil.

Back in the IMS labs, Zhang examines a sediment sample to look for signs of an increase in carbon in the soil. The soil samples can show changes in carbon storage over long periods of time.

“It is wonderful that UNC Energy Services had the foresight to fund this pilot project that harnesses our expertise in coastal science and leverages the physical location of our Institute of Marine Sciences to make progress toward meeting our sustainability goals,” Piehler said.

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