Abstract

Recent efforts to assess the ability of current salt marsh extent to persist over the next 50-100 years conclude that under intermediate sea-level rise (SLR) projections, salt marsh extent in North America will suffer a dramatic decline by 2100. This occurs as the rate of SLR reaches 12-14mm/y, exceeding the ability of most marshes to accrete sufficient sediment to keep up, and migration space becomes limited, eliminating the ability of marshes to move up. Increasing future marsh resilience by building or restoring marshes at higher elevations often comes with a contemporary decrease in the provision of some marsh ecosystem services, such as fishery use, denitrification, and primary production, which are optimal at mid to low marsh elevations. Current state and federal environmental laws and regulatory policy are designed to protect current salt marsh habitat, and prevent actions that result in a loss of habitat and associated ecosystem services. An approach that better balances the need to protect current marsh habitat with the need to ensure future marsh habitat is needed to create and restore resilient coastal wetlands. Marsh restoration and resilience projects should be evaluated over a 50-75 year time period, utilizing updated NOAA SLR predictions and spatial models incorporating projected SLR rates and migration space. Examples of marsh restoration and shoreline stabilization projects that provide long-term marsh resilience to SLR, but may reduce ecosystem services short-term, are provided from sites in North Carolina.