Building a Better Coast with Living Shorelines

by Rachel O’Connor

A protected and stabilized shoreline that is made of natural materials such as plants, sand, or rock.

Living shorelines use plants or other natural elements—sometimes in combination with harder shoreline structures—to stabilize estuarine coasts, bays and tributaries.

—National Oceanic and Atmospheric Administration

As society looks toward natural solutions to protect our coasts, blue infrastructure is becoming more and more attractive due to its sustainable traits. Management companies are looking toward an upand-coming, forward-thinking method of erosion control as their new go-to solution: living shorelines.

Living shorelines stand out from other kinds of erosion control since they’re known as “soft structures”—using natural elements such as marsh plants and oyster shells in their construction. Hard structures like revetments and seawalls can cause waves to curl downward and carry sediment off the land and out to sea; this can increase erosion and undermine the hard structures. By contrast, living shorelines slow down wave energy and allow plants and the pores in reefs to capture sediment.

Living shorelines can include harder surfaces such as oyster reefs and local plants. In North Carolina, a common plant for our living shorelines is Sporobolus alterniflorus, commonly known as saltmarsh cordgrass or smooth cordgrass. The water slows when traveling over the rocks and reefs, then slows more when passing through the plants. At this pace, water drops sediments like sand and mud within the plants and the reef, allowing the land to build up behind the reef. The plant roots keep the soil in place and prevent strong waves from having a devastating impact on the shoreline.

Another benefit of living shorelines is that they create habitats for local species. Blue crabs (Callinectes sapidus), an economically important species for North Carolina, live off the structure’s resources and use adjacent seagrass beds to lay their eggs. Many fish species also spend their juvenile period in these ecosystems before heading to sea, making living shorelines incredibly beneficial in areas with commercial and recreational fishing.

Let’s look at a couple of local projects in the region making strides in living shoreline development.

Started in 2004, the St. James project in Brunswick County works with the University of North Carolina Wilmington (UNCW) to monitor the research sanctuary while serving as a citizen science opportunity. Local residents, including high school students and the local Boys and Girls Club, have the chance to attend talks hosted by leaders of the St. James community and UNCW researchers. Community members can contribute by bagging recycled oyster shells, planting marsh grasses and cleaning up the local waterways. Interested in helping? Contact J. Taylor Ryan, President of the St. James Conservancy, The Royal Order of the Honorary St. James Oyster, at jtaylorryan@msn.com or by calling (201) 924-5199.

Finished in 2019, the Sunset Beach living shoreline project is 250 feet long and includes oyster reefs, a vertical sill and native plants. The project was a recipient of the $35,000 Duke Energy Water Resources Fund to help with the threat of erosion on Sunset Beach. Interested in volunteering at living shoreline sites like this one? Reach out to the North Carolina Coastal Federation—one of the project’s partners—at www.nccoast.org/get-involved/ to see how you can help.

There are plenty of opportunities to visit some of the living shorelines in the area whether by foot, kayak or paddleboard. However, if you are going to visit them, keep a healthy distance from the oyster reefs to avoid running into them and breaking parts off. If you want to walk the mudflats or sandy areas—which is best done at low tide—make sure you wear close-toed shoes as sharp oyster shells could be present.

If you are going to visit a living shoreline, be prepared for the smell. Living shorelines and local wetlands are amazing carbon sinks, but that lack of oxygen causes frequent sulfur build-ups. (For those who haven’t smelled sulfur before, it smells like rotten eggs.) The carbon storage that living shorelines and neighboring wetlands provide plays an important role in combating erosion while balancing the community’s output of greenhouse gasses. Despite their benefits, wetlands are at risk. While development cannot always be prevented, supporting locations where living shorelines can be built can help protect wetlands to an extent.

For families or individuals wanting to learn more about living shorelines, the North Carolina aquariums are a great interactive resource, especially when you aren’t able to access one easily elsewhere. For residents of southeastern North Carolina, the North Carolina Aquarium at Fort Fisher is a convenient option located south of Kure Beach. However, if you’re up for a drive, the North Carolina Aquarium at Pine Knolls is a fantastic option given its oyster reefs on display outside.

Once you’ve seen living shorelines in action and learned how they protect our shore, you may be inspired to support them. You can do so by talking with friends and neighbors about the benefits, volunteering to bag oyster shells, planting cordgrass or participating in a waterway clean-up. No matter how you choose to support living shorelines, know that your doing so helps protect the environment for future generations.

Davis, J.L., Currin, C.A., O’Brien, C., Raffenburg, C., and A. Davis. 2015. “Living Shorelines: Coastal Resilience with a Blue Carbon Benefit.” PLOS ONE. Accessed by journals. plos.org/plosone/article?id=10.1371/journal. pone.0142595

Nahlik, A.M., and M.S. Fennessy. 2016. “Carbon Storage in US Wetlands.” Nature Communications (7). Accessed by: nature. com/articles/ncomms13835

Young, S.S., Rao, S., and K. Dorey. 2021. “Monitoring the Erosion and Accretion of a Human-built Living Shoreline with Drone Technology.” Environmental Challenges. Accessed by sciencedirect.com/science/ article/pii/S2667010021003577

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oceanservice.noaa.gov/ecosystems/ coastal-blue-carbon/

Rachel O’Connor is an intern with Cape Fear’s Going Green. Rachel gardens, explores and learns languages.