Doctor of Philosophy (Ph.D.)
Virginia Institute of Marine Science
Donna M Bilkovic
Sarah L Stafford
Societies and ecosystems are interlinked entities as there are feedbacks and dependencies between the systems and these can be viewed as an integrated, social-ecological system. Social and ecological research is often conducted independently which contributes to management recommendations that are premised on a false dichotomy. Compounding these challenges, climate change is accelerating and continues to exacerbate socio-ecological stressors. Coastal wetlands, such as salt marshes, are particularly vulnerable to sea level rise and coastal development. Shoreline erosion is often managed through installing engineered shoreline armoring (i.e., bulkhead) that reduces many of the natural adaptive mechanisms present in coastal ecosystems. In contrast, natural and nature-based features (e.g., living shorelines) can protect coastal properties from storm damage and reduce erosion while potentially adapting to new conditions. The goal of this dissertation is to integrate social and ecological assessments of shoreline systems to improve coastalmanagement, with different chapters addressing different elements of the shoreline social-ecological system (Figure 1). Chapter 2 includes a comprehensive comparison of nekton habitat use at living shorelines and natural marshes over a range of living shoreline age and environmental settings. It shows that living shorelines provide similarly suitable nekton habitat as natural marshes. Chapter 3 examines property owner perceptions of shoreline modifications and how they relate to their decision making. This chapter reveals that property owners often perceive riprap to be more effective than living shorelines at erosion control, withstanding storms, and adapting to sea level rise. Although the ecological benefits of living shorelines are often recognized, these benefits are not often factored into property owner shoreline decision making. Chapter 4 evaluates how social interactions affect property owner decision making and simulates how these social groups can affect tidal marsh sustainability. This work shows that NGOs, state employees, and friends are often influential for living shoreline property owners which indicates a greater need for NGOs and state employees to engage in local communities. Yet, even under accelerated rates of living shoreline implementation by individual property owners, the modification rates may be to be too slow to meaningfully offset anticipated marsh loss from shoreline development and sea level rise. Chapter 5 uses a social-ecological network analysis to evaluate how ecosystem services are considered in shoreline policy and during decision making. Ecosystem services are used as a bridge between the social and ecological components. Results show that marsh structures that contribute to the desired ecosystem services are not explicitly considered in polices or during decision making. There is a need to reevaluate the underlying assumptions of coastal policies. This dissertation affirms that living shorelines provide necessary ecosystem services, such as nekton habitat, but these benefits are not realized by property owners. The piecemeal and property owner-driven approach of shoreline modification for stabilization is currently ineffective in protecting salt marsh habitat. This indicates there is a need for a more comprehensive shoreline management approach that accounts for regional spatial scales and incorporates the underlying functions of a marsh that create many socially desired benefits.
© The Author
Guthrie, Amanda Grace, "Improving Coastal Management Through Integrating Social-Ecological Assessments" (2022). Dissertations, Theses, and Masters Projects. William & Mary. Paper 1673281622.
Available for download on Friday, July 21, 2023