Seattle University


Environmental Studies

Faculty Mentor

Tanya Hayes


Coastal hazards, such as erosion and flooding, are a danger to people and property. The typical defense against coastal hazards has been grey infrastructure, which can lower biodiversity and erode the shoreline further by preventing natural sand replenishment. Natural defenses (e.g., habitat restoration, living shorelines) have been suggested as a means to address shoreline erosion and flooding. It is uncertain, however, if natural defenses are effective at combating coastal hazards. This review analyzes existing literature on natural defenses to assess whether they can provide an effective and ecologically sound means for coastal hazard management, with an emphasis on California coastal management. The literature indicates that natural defenses are ecologically better than grey infrastructure, living shorelines can be used as an effective form of erosion control, and that there needs to be further research on the long-term effects of restoration. Based on the key findings, this paper recommends conserving existing natural coastlines and adding vegetation to the grey infrastructure that is already in place.