An Interdisciplinary Assessment of Nature-Based Shoreline Stabilization Techniques

Abstract

Coastal shorelines are increasingly threatened by erosion, exacerbated by human activities and climate change, placing infrastructure, property, and critical habitats, such as salt marshes, at risk. Nature-based (NB) solutions, including living shorelines, have emerged as promising alternatives to hardened structures, yet uncertainties remain regarding their engineering performance, ecological outcomes, and public adoption. Here, I integrate geomorphological monitoring, ecological field studies, and social science approaches to evaluate engineering performance, ecological co-benefits, and public perceptions of NB shoreline stabilization strategies (living shorelines [LS]) in coastal North Carolina (NC). Using drone-based structure-from-motion photogrammetry, I quantified shoreline and elevation change across sites with and without LS and assessed how uncertainty thresholds influence interpretation of shoreline stabilization outcomes. All sites experienced marsh edge retreat, and in most cases, elevation loss within 2-3 years post-restoration, with vertical uncertainty thresholds significantly affecting volumetric change estimates. Concurrently, field surveys and long-term datasets revealed that LS enhanced fish abundance in adjacent marsh habitats without negatively impacting nekton use of nearby seagrass areas. Further, concrete-based LS breakwaters supported greater oyster recruitment than conventional LS shell bag breakwaters. Despite demonstrated ecological and coastal protection benefits, adoption of LS remains limited. Using a mental model survey method, I found that while many waterfront property owners in NC prefer LS to hardened shorelines, shoreline stabilization approaches are generally limited by practical barriers such as cost, permitting, and a lack of expert guidance. These findings suggest that increasing use of LS will depend on making LS more accessible and easier to implement than hardened shorelines. By linking physical outcomes, ecological responses, and human perceptions, this work provides a comprehensive evaluation of NB shoreline approaches and offers insight to improve monitoring practices, inform policy, and enhance stakeholder engagement in coastal management.