Creating a Shoreline Protection Feature- Fall 2017 Internship Post

Hi! I’m Emily Pierce and I’ve been interning at the Coastal Studies Institute with Dr. Lindsay Dubbs this semester. I had a lot of freedom when deciding the focus of my internship and eventually deciding to take on a project with the Pine Island Audubon Sanctuary here on the Outer Banks with the help of the director there Robert Fearn.

My goal was to use natural vegetation from the Pine Island shoreline and create some sort of experimental shoreline protection feature to help prevent erosion at a lower cost than most popular shoreline protection strategies. Because the Pine Island Shoreline is on the

A view of the Pine Island Shoreline

Albermarle Sound with shallow waters and changing wind patterns, the main cause of erosion is the frequently changing water level; in order to target this problem, the first step was to plan and research protection measures that can move with the changing water level.

After a lot of literature review and consultation with Lindsay, I decided to model my project after a floating breakwater structure, but mine would be made out of bundles of natural vegetation like cordgrass. Because there was such little precedent on using bundled vegetation for erosion protection, I also wanted to conduct floatation and decomposition experiments to get an idea of how feasible and long lasting a protection measure like this would be.

A test bundle off the dock at the Coastal Studies Institue

With some help from Lindsay, Lab technicians Claire and Ted, and my peers I was able tocollect cordgrass from Pine Island on several occasions to be used for creating bundles and testing floatation and decomposition over time. The Vegetation was bundled into rolls about 30 centimeters in diameter and 3 meters long using natural twine. Test bundles

Machetes were used to cut large cordgrass stems from Pine Island
Photo by Brett Wells



were placed into the water off the dock at the Coastal Studies to start the floatation study. It became clear that the bundles wouldn’t be able to float for extended periods once being waterlogged, so we decided to add two pool noodles as core for each bundle.

Bundles were placed at two locations on Pine Island, one receiving north eastern winds and the other receiving south western winds, on October 23rd. Bundles were placed using steel stakes and secured with rope so they were able to float. In order to measure the success of the protection measure PVC pipe was also placed in front of and behind the bundles to be used a reference point for measuring sediment accretion. The distance between the bundles and the shoreline was also measured to help provide a reference for determining success of the bundles in preventing erosion.

Samples for the decomposition study placed in a shaker bath simulating water movement of the natural sound system

When the bundles were placed at Pine Island, water was also collected from the sound to be used in the decomposition study. In order to determine how long the grass can function and what it produces as it decomposes, subsamples of cordgrass in sound water, just sound water, and distilled water were placed in separate glass containers and subjected to environmental conditions using an incubator. Small amounts from each sample are being filtered periodically to get data on total organic carbon and chlorophyll A.

While its likely that I won’t be able to make far reaching conclusion on the success of using vegetation bundles as a shoreline protection measure before the semester ends, my project does represent a unique approach that could provide some interesting information for the future of shoreline protection.

I’d like to extend a big thanks to Lindsay for not only hoping to guide me through this project, but also for introducing me to joys of field research and the beauty of an imperfect process from start to finish. While it of course comes with frustration, working on something that has little prior research or application is absolutely an exciting experience that I’m ever grateful for.




The First Birthday and a Trip to the Dismal Swamp

This week was quite eventful. We started the week with internships on Monday during which some people got to sit in on a court case, help recover baby sea turtle nests, or participate in discussion about zoning and town planning. On Tuesday we had a full day of classes, including a class outside learning about different marsh systems. Towards the end of the week, we had our first birthday at the field site, shoutout to Emily Inkrote, and we made a trip to the Great Dismal Swamp with a few special guests.

Emily Inkrote turned twenty on Thursday, so of course we had to celebrate. Since it was the first birthday in the program, we had to go all out to celebrate. We made dozens of signs to hang around the house and at her desk, we decorated her car with lots of streamers and balloons, and we made a giant cookie cake. Everybody had a great time putting together a surprise for Emily and at the end of the day we made our weekly trip to Food Dudes Kitchen where we indulged in taco Thursday.

Decorating a cake for the festivities

On Friday, we made the journey to the Great Dismal Swamp in Virginia to take a scenic kayak tour with Bland Simpson and Rachel Willis from UNC. Another Rachel from the community garden we spend time at joined us as well with her husband. Our trip lasted about five hours and took us through a really interesting ecosystem. It was a good end to the week.

A view from the kayak