Since fall 2025, NCCOS scientists have been supporting NOAA’s National Marine Fisheries Service (NOAA Fisheries) Habitat Conservation Division with evaluating the performance of various living shoreline approaches in coastal North Carolina.
Living shorelines are a more natural way to help reduce shoreline erosion, while also providing habitat for fish and wildlife, and protecting coastal communities from wave action and storm surge. The structures vary in the amount of natural material that is incorporated into the design, which has been termed green to gray scale, with green living shorelines being composed mostly of natural materials, such as oysters and marsh plants, and gray living shorelines being predominantly hard larger structures.
NOAA Fisheries consults with the U.S. Army Corps of Engineers on permit applications for these structures under authority of the Magnuson Stevens Act. These structures are placed on shallow Essential Fish Habitat and public trust waters that fish and invertebrates use for feeding and predator protection. Consequently, it was important to verify the long-term effectiveness of this relatively new technique to enhance shoreline habitat as well as stabilizing shorelines.
Several types of living shorelines have been constructed in North Carolina, all of which are composed of various materials that form a sill and are located parallel to and waterward of the marsh’s shoreward edge (see photo to the right). These range from low profile oyster shell bags, small riprap, and oyster castles, to higher profile structures, such as large granite rock sills and concrete-based structures including Quick Reef (a proprietary mixture of calcium carbonate materials cemented together with pieces leaning against each other like a tent), Natrx ExoForms (naturalistic modular cement structures), and Wave Attenuating Devices (concrete reef balls and pyramids). Oyster Catcher structures are another concrete-based structure (patent-pending biodegradable plant fiber cloth coated in a mineral-based hardening agent) that forms tables and other unique low-lying shapes, designed to resemble a colonized oyster reef.
Researchers have intensively monitored several sites in North Carolina. However, with over 200 living shorelines in the state, NOAA Fisheries wanted to conduct a rapid assessment on additional structures of different ages and construction materials to discover their effect on oyster populations, marsh expansion, sediment accumulation, and fish access.
Scientists from NCCOS’ Coastal Resilience, Restoration and Assessment team are partnering on this effort. A core part of the team’s mission is to evaluate the performance of nature-based solutions like living shorelines and provide guidance on where they work best. The collaboration with NOAA Fisheries ensures that the findings will inform real-world management decisions (such as permitting) and provide findings that may guide future living shoreline designs. For this round of assessments, NOAA Fisheries and NCCOS – joined by staff from North Carolina Coastal Federation, North Carolina Department of Environmental Quality, and the North Carolina National Estuarine Research Reserve – surveyed an Oyster Catcher sill using a real-time kinematic global positioning system, specifically collecting data on elevation of the sediment just in front of the sill, the top of the sill, and the elevation of oysters attached to the substrate and sill material. The team filled out a data sheet noting erosion (if any), the vegetation present, fish and invertebrate usage, and ranked the effectiveness of the site.
These field assessments help quantify shoreline stabilization, habitat benefits, and long-term project effectiveness, while providing an opportunity to leverage federal, state, and local efforts in stabilizing shorelines and habitat restoration. The collection of elevation data by NCCOS will aid in understanding the optimal target elevation for future structure placements.
This work is supported by the Coastal Zone Management Act. Learn more about the NCCOS efforts in evaluating the performance of Nature-based Solutions.
