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

The Final Report for the NE CASC project, "Mapping Salt Marsh Response to Sea Level Rise and Evaluating 'Runneling' as an Adaptation Technique to Inform Wildlife Habitat Management in New England", is now available. Led by Linda Deegan of the Woodwell Climate Research Center, this project was designed to assess the impact of  runneling, a novel method for restoring salt marshes, on key wildlife habitat. 

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 salt marsh 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, Deegan and her collaborators studied an emerging restoration technique called "runneling," which involves the digging of tiny channels in inundated salt marshes to revive natural tidal flushing and bring them back to life. In a large-scale experiment spanning two Massachusetts salt marshes, researchers showed that runneling successfully restores critical vegetation, even in challenging conditions. Working across a wide range of elevations and initial conditions, the research team demonstrated that critical wildlife habitat recovered following runnel installation whereas habitat continued to decline when no intervention was attempted. Motivated by the growing popularity of runneling among practitioners in the coastal management community, this project thus provides rigorous data regarding the effects of this approach and can be used to inform decision-making regarding future restoration projects. 

Another aspect of this project involved the development of maps to help identify marshes that might benefit from runneling  while also being high-priority areas for wildlife protection. In this part of the project, the research team sought to give resource managers the tools needed to restore marshes, protect wildlife, and combat the effects of climate change. By identifying target areas with the best chances of recovery, this work can help ensure the survival of these vital ecosystems and the species that depend on them.