This Land is Your Land. This Land Could be Marsh Land: Identifying the intersections of marsh migration and coastal land use.
Citation:
Mulvaney, K., E. Burman, N. Merrill, M. Bradley, AND C. Wigand. This Land is Your Land. This Land Could be Marsh Land: Identifying the intersections of marsh migration and coastal land use. International Association for Society and Natural Resources 2023 Conference, Portland, ME, June 11 - 15, 2023.
Impact/Purpose:
As sea levels rise, salt marshes are projected to potentially migrate landward. To allow for migration certain ecological and social conditions will need to be met. While there is increasing understanding of the ecological conditions (land slope, soil types, and more), there is little understanding about the social conditions. We investigated two of the potential social considerations for marsh migration: 1) land ownership and values, and 2) hazardous and contaminated sites. We found notable differences between the social conditions of current marsh and the conditions of the projected future marsh.
Description:
Due to sea level rise, salt marshes are projected to “migrate” landward as saltwater drowns existing marsh and creates new potential marsh conditions in what is currently non-marsh condition. The fate of marsh migration will be decided by the communities surrounding those marshes and the land use change they are willing to accept and implement. Using landscape-scale geospatial analysis for the state of Rhode Island, we investigated two of the potential social considerations in marsh migration: 1) land use change from private to public for coastal lands, and 2) overlap of marsh migration pathways with hazardous and contaminated sites. We overlaid projected 2050 marsh migration models (NOAA’s SLAMM model) with publicly available data on hazardous and contaminated sites as well as purchased parcel attribute data. We found the majority of extant salt marshes are on public lands with few hazardous and contaminated sites. The projected new marsh pathways show notable land use differences from the extant marsh. They are projected to be primarily private parcels (residential, commercial, and agricultural) that range considerably in size and assessed value and contain potentially thousands of hazardous and contaminated sites. To enable migration, many of these lands will need to be put into conservation programs or would require behavior change by landowners (for example not mowing in the marsh pathways). There also needs to be consideration and remediation of hazardous and contaminated sites that would allow for safe saltwater inundation. Coastal communities are increasingly planning for sea-level rise through community resilience planning, but marsh migration and hazardous sites are often not a component of planning. In Rhode Island, and many other coastal areas, these considerations have separate managers and funding, but could be incorporated into a more comprehensive coastal resilience planning to provide for synergies in funding and effort across these sites to identify the areas with most potential for ecological and social benefits.
