UNC Living Shoreline Studies

Overview 

As development near coastal and estuarine ecosystems increases, so does the frequency of shoreline stabilization by property owners and industry. Shoreline hardening refers to a type of shoreline stabilization that uses materials like concrete, metal, wood, or rocks to protect a shoreline from erosion. The collective increase in hardening techniques can result in a loss of North Carolina's estuarine habitats, which is why it is imporantat to inform property owners about softer, or natural, techniques that not only reduce erosion, but also improve habitat. 

An alternative to shoreline hardening projects are living shorelines. Living shorelines prevent erosion through strategic placement of natural substances such as vegetation and oysters. Living shorelines help with stabilization by buffering wave energy and trapping sediments, which increases shoreline elevation. They also improve the overall health of coastal and estuarine ecosystems by providing nursery and foraging habitat for marine organisms and shorebirds, and improve water quality by filtering out pollutants.

The two projects featured below investigate the effects different shoreline stabilization methods have on habitat function, shoreline erosion and sedimentation, and the structural integrity of stabilization methods after intense storms. 

About the Projects 

In 2012, researchers at the University of North Carolina-Chapel Hill Institute of Marine Sciences (UNC IMS) published a study titled Fisheries Habitat Impacts of Marsh Sills (Living Shorelines) as a Shoreline Stabilization/Restoration Alternative to Bulkheads. The project focused on the effectiveness of marsh sills on maintaining and restoring coastal habitats for fish and crustaceans. To accomplish this, the researches compared biodiversity and habitat use in marsh sills, bulkheads, and natural marshes. Results indicate that marsh sill sites serve as an additional refuge from predators for juvenile fish and crustaceans, provide new hard substrate for oysters and other organisms, and may serve a similar function as intertidal oyster reefs (Peterson and Bruno, 2012).

In 2014, a second study, assessed the damage to stabilizing stuctures after Hurricane Irene. Out of the structures assessed (sills, riprap, hybrid riprap/bulkhead, and bulkheads), only bulkheads showed visal damage after the storm. Stabilization methods were compared to gain better insight into which methods enhance resource availability, maintain shoreline integrity, and are cost effective. The findings in this study can be used by policy makers developing policies for coastal management of estuarine shorelines and the ecosystem services they provide (Gittman et al., 2014).