Maine Natural Areas Program Launches Marsh Migration Model to Address Sea Level Rise

May 7, 2024

For more information contact: Lisa St. Hilaire at:

Augusta, ME - The Maine Natural Areas Program (MNAP) within the Department of Agriculture, Conservation and Forestry (DACF) has introduced an updated marsh migration model and a comprehensive report. This initiative aims to help communities and land managers identify critical areas necessary for the inland migration of tidal marshes anticipated under projected sea level rise scenarios.

Maine's approximately 22,000 tidal marsh acres provide diverse ecosystem services such as carbon sequestration, water quality enhancement, recreational opportunities, and habitat for various plant and animal species. Additionally, they serve as natural buffers to coastal communities, mitigating flooding and reducing the impact of storm surges and waves. However, these vital ecosystems face threats from sea level rise, coastal development, and other human-induced disturbances. As sea levels continue to rise, existing tidal marshes may respond by either "keeping up" through sediment deposition or migrating inland, depending on geomorphic conditions and land-use factors.

MNAP's updated tool presents current tidal marsh areas along the Maine coast alongside projected migration spaces, enabling planners, local leaders, and conservation organizations to visualize and plan for marsh migration under various sea level rise scenarios, ranging from 1.2 to 10.9 feet.

An analysis of potential marsh extent indicates that Maine is likely to experience a net loss of tidal marsh habitat over time, as some current marshes may become inundated, and available migration space is limited. Only approximately 31% of potential marsh migration space across all sea level rise scenarios is conserved statewide, underscoring the need for additional conservation efforts for current and future marsh areas.

Kristen Puryear, MNAP Chief Ecologist, emphasizes the situation's urgency, stating, "Tidal marshes and other valuable coastal habitats are facing unprecedented challenges due to rapidly rising seas, with the threat expected to escalate in the short and long term." Puryear highlights the significance of marsh migration space modeling in aiding informed decision-making by land managers, conservation planners, and municipalities regarding land use, management, restoration, and conservation strategies. "By safeguarding marsh migration space, we are protecting these ecosystems today and ensuring their resilience in the face of future challenges. It's a win-win situation," she adds.

The MNAP marsh migration resources and a companion report are available at MNAP Coastal Resiliency.

The Maine Geological Survey, Maine Coast Heritage Trust, and The Nature Conservancy are contributing partners to this initiative. The Maine Outdoor Heritage Fund and the U.S. Environmental Protection Agency supported funding.

Supporting documents

Tidal marsh migration illustration - courtesy Maine Natural Areas Program.