Linking Coastal Adaption Portfolios to Salt Marsh Resilience and Ecosystem Service Values

This project is an international and interdisciplinary collaboration led by Marsh Institute researchers, with collaborators at the Virginia Institute of Marine Sciences and Monash University in Melbourne, Australia. Tidal marshes are one of the most common natural features used for coastal adaptation (protecting the coast from flooding and storms), and are frequently promoted for their ability to support coastal resilience and valued ecosystem services. However, marsh resilience depends on the complex interplay of natural dynamics and human actions. The preservation of marsh transgression zones is among the most critical of these actions; transgression zones are undeveloped coastal areas that allow marshes to migrate inland as sea levels rise, hence promoting marsh resilience. Yet the effect of these zones depends on uncertain sea level rise (SLR) and natural dynamics, which determine how, when and where marshes migrate. These uncertainties and dynamics imply that diversified portfolios of adaptation actions (e.g., preserving different types of transgression zones in different areas) are best able to ensure the resilience of marsh areas and resulting social values. This project will develop tools that address a central coastal adaptation question: Considering the influence of SLR and other uncertain factors on tidal marsh resilience, how can information on biophysical dynamics and economic benefits and costs be coordinated to identify optimal, diversified portfolios of adaptation actions that best sustain marsh resilience and ecosystem service values? The project will develop and illustrate the methods and resulting insights using data from multiple Long Term Ecological Research (LTER) sites.