Aligning salt marsh conservation and hazard mitigation objectives in a changing climate

Decision making for action in coastal conservation, hazard mitigation and climate change adaptation can only benefit from a wider understanding and attribution of the benefits provided by functional, protected salt marshes. Few studies, however, have examined the role of salt marshes in coastal protection and my research addresses this knowledge gap. In the first chapter, I conducted a literature review and meta-analysis of the effect of salt marsh vegetation on the processes of wave attenuation, shoreline stabilization and floodwater attenuation. In the second chapter, I used a GIS-based approach to quantify potential increases in storm surge risk due to sea level rise on Long Island, New York. Finally, in my third chapter, I developed a case study on Long Island using the conservation planning software Marxan to identify marsh areas suitable for conservation action that also have the greatest capacity to provide benefits related to coastal protection of human communities.;Three conclusions emerge from this work. First, salt marsh vegetation has a significant positive effect on the marsh processes of wave attenuation and shoreline stabilization and likely mitigates coastal flooding to some extent. Second, even modest and probable sea level rise will likely increase risk in many coastal areas and will potentially create risk where it was not before. Third, objectives related to hazard mitigation and climate change adaptation can be incorporated into a conservation planning framework without greatly increasing the total area of sites required to meet all objectives. Together these results suggest that coastal planners can and should begin to account for salt marsh ecosystem services when planning for biodiversity conservation, hazard mitigation and climate change adaptation. Addressing these objectives simultaneously can help ensure delivery of salt marsh ecosystem services in the future while providing for safe and sustainable coastal communities.