Thin-layer Sediment Placement: Evaluating an Adaptation Strategy to Enhance Coastal Marsh Resilience - NERRS/NSC(NERRS Science Collaborative)

Thin-layer placement (TLP) is an emergent climate adaptation strategy that mimics natural deposition processes in tidal marshes by adding a small amount of sediment on top of marsh in order to maintain elevation relative to sea level rise. This project addressed the needs of coastal managers and restoration practitioners for more information about TLP's effectiveness across diverse marsh plant communities and regions. Researchers conducted coordinated restoration experiments at eight National Estuarine Research Reserves across the East and West Coasts. The team assessed the impact of elevation, sediment type, and layer thickness on the success of this marsh adaptation technique. Greenhouse experiments exploring the effect of sediment texture and the addition of biochar as a soil amendment complemented these field studies. To support future use of TLP, the project team and an advisory committee of coastal managers at state and federal agencies and nonprofit groups created a suite of guidance documents including a consensus statement on thin-layer placement in tidal marsh ecosystems.