The Use of Living Shorelines

By Mary Schoell and Marnita Chintala

As we looked out over the water, sounds of laughter from distant kayakers could be heard over the soft ripples that lapped the eroded edge of salt marsh. From this view, it was easy to understand that Sengekontacket Pond—the same pond where Jaws was filmed 41 years ago—and the adjacent salt marsh habitat at Felix Neck Wildlife Sanctuary represented the quintessential beauty of Martha’s Vineyard. However, this area is threatened by both impaired water quality and negative environmental changes, which have eroded almost ten feet of marsh in recent years.

The need for shoreline stabilization inspired a collaboration with the Felix Neck Wildlife Sanctuary, the Shellfish Departments of Oak Bluffs and Edgartown, the University of Rhode Island, and a team of us from EPA’s Atlantic Ecology Division to address the social and ecological aspects of coastal restoration.

a group works on installing the living shorelines

The crew hard at work installing the living shoreline

For the ecological component we applied a natural approach to salt marsh restoration, called a living shoreline. This technique uses natural materials such as coconut fiber coir logs and oyster shell bags that cup the marsh edge (see photo to the right). These materials are arranged to reduce wave energy to both enhance the existing marsh and facilitate the growth of new salt marsh area.  Because of concerns with nutrient loading in Sengekontacket Pond, the project has also provided us with the perfect opportunity to examine how the use of alternative technologies such as a living shoreline can aid in nitrogen removal.

Understanding changes in nitrogen, water, soil, plant, and animal health at our sites over time will provide novel information about the practicality and success of living shorelines in New England. The endeavor also incorporates a University of Rhode Island social science study about the public response to this type of restoration and how personal interests and values influence and define restoration success.

hand made bags filled with shells

We designed and sewed our own biodegradable shell bags.

To date, we have installed two living shoreline areas. We have deployed close to 50 coir logs (12 ft long and 130 lbs each) and around 600 shell-filled bags (3 ft long and 30 lbs each) out onto the marsh this summer—making this surely one of the more physically demanding projects that we have gotten ourselves into here at the Atlantic Ecology Division.

Because this is a collaborative project, many stakeholders means many different values and needs. Although we designed this project as an experiment to answer specific quantitative questions about living shorelines, we quickly learned that compromise and communication are crucial for success. Felix Neck Wildlife Sanctuary values the preservation of nature and is committed to providing opportunities for the public to gain environmental awareness. To honor these goals, we tailored our sampling and monitoring methods to minimize the impact we have on the marsh landscape. To ensure that every piece of the project is environmentally friendly, we avoided the use of plastic shell bags and instead designed and sewed our own biodegradable bags. We have also created an informative poster so marsh visitors can learn about what we are monitoring along the shoreline and why it’s important to track these changes over time.panorama of shoreline

The project is at the interface of physical restoration, scientific research, social science, and public education. Not only will this living shoreline work help shape decision making in the context of shoreline stabilization techniques, but it will facilitate public awareness of salt marsh erosion and the need for natural shoreline restoration.

About the Authors: Mary Schoell is a student services contractor working with EPA’s Atlantic Ecology Division. Marnita Chintala is a Branch Chief at the Atlantic Ecology Division and is a Task Lead within the Sustainable and Healthy Communities research program.