Landward migration of tidal saline wetlands with sea-level rise and urbanization: a comparison of northern Gulf of Mexico estuaries

Coastal wetland ecosystems are expected to migrate landward in response to accelerated sea-level rise. However, due to differences in topography and coastal urbanization extent, estuaries vary in their ability to accommodate wetland migration. The landward movement of wetlands requires suitable conditions, such as a gradual slope and land free of urban development. Urban barriers can constrain migration and result in wetland loss (coastal squeeze). For future-focused conservation planning purposes, there is a pressing need to quantify and compare the potential for wetland landward movement and coastal squeeze. For 41 estuaries in the northern Gulf of Mexico (i.e., the USA gulf coast), we quantified and compared the area available for the landward migration of tidal saline wetlands and the area where urban development is expected to prevent migration (coastal squeeze), under three alternative future sea-level rise scenarios (0.5-, 1.0-, and 1.5-m by 2100).