ECU researchers lead efforts to understand dynamic coastal interactions

Along the coast of North Carolina and around the world, there is a delicate and dynamic balance between coastal ecosystems and communities. East Carolina University researchers are at the forefront of efforts to better understand those interactions and shape future policy and decision-making.

An interdisciplinary team of researchers from ECU’s Department of Coastal Studies is involved in several grant-funded projects to document, explain and model how coastal ecosystems — such as mangrove swamps and coral reefs — act as a buffer against the impact of hurricanes and how the policies and decision-making of coastal communities affect those ecosystems.

Dr. Siddharth Narayan, assistant professor, is the principal investigator on a project funded by a $1.6 million grant from the National Science Foundation. ECU’s Dr. Nadine Heck and Dr. David Lagomasino are co-principal investigators on the project, along with Dr. Stacy Jupiter from the Wildlife Conservation Society and Dr. Manoochehr Shirzaei from Virginia Tech.

Circular interactions

The team is studying how mangrove and coral reef resource systems are shaped by external hurricane impacts and how they influence those impacts, Narayan said.

Dr. David Lagomasino, top, works with a team to take soil cores in a coastal wetland.

Dr. David Lagomasino, top, works with a team to take soil cores in a coastal wetland.

“When you think of a mangrove or reef system, it’s not just the mangroves and the coral reefs. It also includes the human communities that are using these mangroves and coral reefs and are often receiving flood protection benefits from them, and in some cases actively managing them for those flood protection benefits,” he said. “So humans are using and modifying these ecosystems. These ecosystems are dynamic in themselves. They interact with each other, they’re providing these benefits to humans, and then you have the impact of a hurricane that comes along and affects the ecosystem.

“It’s going to affect the mangroves and reefs. And it is also going to affect the coastal human communities, and so it is in that context that we’re trying to understand all of these links.”

The connections are complex, he said, which is why the interdisciplinary nature of the coastal studies department, part of ECU Integrated Coastal Programs, is such a strength. Lagomasino brings expertise as a remote sensing ecologist, Narayan is a coastal engineer and Heck is a human environment geographer. The other partners bring additional expertise in such areas as flooding, community engagement and data collection, he said.

“Each of us has our own specific discipline, methods and expertise that we bring into this, and each of us has specific research questions,” Narayan said. “We have a framework within which we will bring all of us these insights together to see what storylines emerge.”

Previous work by the researchers has shown that losing coastal ecosystems such as mangroves, salt marsh wetlands and coral reefs means losing the protection they offer, and that communities need to take those ecosystems into consideration when rebuilding after storms.

The study will focus on vulnerable coastal communities in Fiji and Puerto Rico, said Heck.

“We want to look at how people respond to (storms) in terms of how they manage, use and protect the mangroves and the coral reefs, and then we use that information to model how those decisions will affect the ability of the coral reefs and mangroves to (mitigate the impact of) future storms,” she said. “Because if I just cut them all down in order to rebuild my house, I’m going to have a lot less flood risk reduction in the future.”

One interesting aspect of Heck’s work is that the management of the coastal ecosystems is very different in Fiji versus Puerto Rico.

“In Fiji, communities own their own lands and their own mangroves, so it’s more communal decision-making,” Heck said. “In Puerto Rico, it’s mostly governed by … national and state agencies. So we’ll look at that difference: How does it work in a more bottom-up, local governance environment versus a more top-down, government driven environment? So who makes the decisions about the mangroves, and does it matter in terms of how people respond?”

By better understanding the dynamics between coastal ecosystems and human beings, the team hopes to provide better information to decision-makers about coastal management.

“Our research will provide important insights into how decisions about managing coral reef and mangrove ecosystems differ across political systems, and how these decisions, in turn, influence the resilience of ecosystems and people to hurricane impacts,” Heck said. “These insights will help decision-makers identify ways in which mangroves and reefs can be managed to protect these ecosystems and enhance coastal resilience.”

View from above

Lagomasino has also received a $1.6 million grant from NASA to study the flood protection benefits of coastal habitats and the impact of storms on those ecosystems. Narayan is a co-investigator on the project.

Coastal wetlands such as mangroves and salt marshes, as well as coral reefs, provide protection in several ways, including building elevation, wave attenuation and flood mitigation, which can help reduce economic loss as a result of storm events, Lagomasino said. They store a large amount of carbon for their surface area.

The decisions and policies of coastal communities have an impact on the ecosystems that act as a buffer against the impact of hurricanes.

The decisions and policies of coastal communities have an impact on the ecosystems that act as a buffer against the impact of hurricanes.

Understanding how storms and other stressors affect these ecosystems is important for maintaining coastal resilience, he added, but the models used for understanding these processes are often based on outdated and broad-scale data.

“NASA is in the business of space, but also of satellites and satellite imagery,” Lagomasino said. “One of the things that NASA is keen on is making sure that we’re not just putting out tons of data and it’s just sitting there; it needs to be integrated into decision-making and management.”

The idea is to make sure that projects like Narayan’s models on flood protection benefits are using the most up-to-date information from satellite imagery that can help generate more accurate flood prediction models, he said.

“This satellite data will give us information about the coastal bathymetry, such as the complexity of those coral reefs and how the topography of the ocean is changing. It tells us about where the mangroves are, where they’re being lost, and the same for the salt marshes,” he said.

It also provides information about elevation and how tall and dense forests are. All of that information can be used to create more accurate and up-to-date models.

“We want to bring all of this information together to create a statistical model that we can then apply to other regions around the world and say, ‘Well, if you have these types of characteristics, this is what you would expect in terms of your flood protection benefits,'” Lagomasino said.

Lagomasino is also part of a team led by researchers at Louisiana State University focused on ecosystem resistance in the Gulf of Mexico. That project is funded by a 3-year, $1.4 million NASA grant.

Interdisciplinary lens

Dr. Reide Corbett, dean of Integrated Coastal Programs, said it is critical to explore and study changing coastal systems from a variety of perspectives, and ECU is a leader in that interdisciplinary approach.

“Coastal systems around the globe are changing due to climate change, sea level rise and other pressures, and our near-term response to these changes will influence these coastal ecosystems for generations,” he said. “It is research like this that will help communities around the nation and the world, not just the specific locations of the work.”

With the recent impact of Hurricane Ian causing loss of life and an economic impact of more than $67 billion, the role of protective ecosystems in mitigating storm damage is a vital research topic, said Dr. Stuart Hamilton, chair of the Department of Coastal Studies.

“These awards will provide research opportunities for ECU undergraduate and graduate students from across a wide range of disciplines while contributing to the body of knowledge related to adaption and resilience to hurricane events,” Hamilton said.

These interdisciplinary projects, along with Dr. Meghan Millea’s participation in a project focused on the hurricane resilience of coastal communities, demonstrate how ECU researchers in a variety of fields are leading the way in applying their expertise to this globally important topic.

North Carolina’s Outer Banks and coastal plains may experience flooding and overwash during hurricanes and tropical storms.

North Carolina’s Outer Banks and coastal plains may experience flooding and overwash during hurricanes and tropical storms.

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