Living Shorelines as a Shoreline Management Practice and Habitat Restoration Strategy

Living shorelines are nature-based coastal protection strategies that are idealized to provide ecological functions similar to that of natural estuarine and coastal ecosystems. Along urbanized coastlines, fringing marsh living shorelines have become an increasingly common alternative to traditional shoreline hardening strategies; however, gaps remain in the understanding of how ecosystem functions and services persist or change in living shorelines over time. Further, there have been limited studies examining strategies to accelerate ecosystem development in these novel systems. This dissertation addresses the aforementioned knowledge gaps by (1) quantifying shoreline protection benefits provided by living shorelines over time and among varied physical settings, (2) examining how eastern oyster, Crassostrea virginica Gmelin, habitat and smooth cordgrass, Spartina alterniflora Loisel, communities developed in living shorelines over a 10-year chronosequence, and (3) testing the role of plant interactions in influencing initial ecological development. Results from these studies indicate that oyster reef living shorelines can provide immediate erosion control, and this service can persist 10 years after installation. My results also show that eastern oyster populations follow a rapid response trajectory and quickly establish along Oyster Castle ® reef living shorelines, whereas smooth cordgrass communities tend to follow a more linear response and require more time to reach near equivalency of natural counterparts. Lastly, my results show that planting designs that focus on maximizing positive species interactions can accelerate vegetation establishment in living shorelines. Additionally, using acclimatized plant sources with intact plant-soil microbiomes was a viable transplant option for living shoreline projects. However, effect of these planting strategies varied by site. Overall, my results suggest that living shorelines are not only an effective shoreline management practice but also a valuable tool for achieving habitat restoration goals.