Mapping Salt Marsh Response to Sea Level Rise and Evaluating 'Runneling' as an Adaptation Technique to Inform Wildlife Habitat Management in New England

Salt marsh loss is a major threat to coastal areas in the Northeast, putting coastal towns, wildlife and ecosystems at risk. Salt marshes filter nutrient runoff, store carbon, protect coastal properties from storm impacts including flooding and erosion, and support a variety of wildlife species. Salt marsh habitats are critical for wildlife species like the Saltmarsh Sparrow, which faces steep population declines and could disappear within 50 years if salt marshes are lost. Rising sea levels are drowning marshes, killing plants, eroding soil, and worsening the problem.

To help restore these vital habitats, we studied an emerging restoration technique called "runneling," which involves creating tiny channels to restore natural tidal flushing in salt marshes and bring them back to life. In a large-scale experiment in two Massachusetts salt marshes, researchers showed that runneling successfully restored critical salt marsh vegetation, even in challenging conditions. Our work demonstrated that across a wide range of elevations and initial conditions, critical wildlife habitat in salt marshes recovered after runnel installation, whereas habitat decline continued without any intervention. As runneling is gaining popularity by practitioners concerned about saltmarsh loss, this project provided rigorous data about the effects of runneling to help practitioners and regulators make decisions about future runneling projects.

This project also developed maps to help identify the marshes that might benefit from runneling and high-priority areas for wildlife protection. The goal is to give resource managers the tools they need to restore marshes, protect wildlife, and combat the effects of climate change. By identifying target areas with the best chances of recovery, this work will help ensure the survival of these vital ecosystems and the species that depend on them.