Evaluating the Impact of Hydrologic Alterations on Salt Marsh Sustainability in a Changing Climate

February 2018

Coastal managers are faced with the challenge of managing marsh hydrology in a way that meets human health needs, optimizes ecosystem services, and supports sustainability. In New England this includes accounting for the effects of ditches that were dug decades ago in 90% of the region’s salt marshes.

Ditches increase marsh drainage and reduce the spatial extent of shallow pools that may represent physical loss of buried soil carbon. However, efficient drainage may reduce the long-term sustainability of marshes by altering below ground biogeochemical and physical processes in a way that results in subsidence and lowered marsh elevation. Managers, restoration practitioners, and scientists at the Waquoit Bay National Estuarine Research Reserve, Woods Hole Oceanographic Institution, U.S. Geological Survey, U.S. Fish and Wildlife Service, National Park Service, and the Cape Cod Mosquito Control Project have expressed a need to understand the tradeoffs of hydrologic management strategies (i.e., ditch remediation, density, maintenance) and identify actions that will achieve user-specified outcomes— such as drainage, maintaining elevation, and carbon burial.

This project is a collaboration between scientists and end users to develop decision-support tools for marsh hydrological management strategies that promote sustainability and delivery of valuable ecosystem services under future sea level scenarios.