Transient coastal landscapes : rising sea level threatens salt marshes

© The Author(s), 2018. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science of The Total Environment 640-641 (2018): 1148-1156, doi:10.1016/j.scitotenv.2018.05.235.Salt marshes are important coastal environments that provide key ecological services. As sea level rise has accelerated globally, concerns about the ability of salt marshes to survive submergence are increasing. Previous estimates of likely survival of salt marshes were based on ratios of sea level rise to marsh platform accretion. Here we took advantage of an unusual, long-term (1979-2015), spatially detailed comparison of changes in a representative New England salt marsh to provide an empirical estimate of habitat losses based on actual measurements. We show prominent changes in habitat mosaic within the marsh, consistent and coincident with increased submergence and coastal erosion. Model results suggest that at current rates of sea level rise, marsh platform accretion, habitat loss, and with the limitation of the widespread “coastal squeeze”, the entire ecosystem might disappear by the beginning of the next century, a fate that might be likely for many salt marshes elsewhere.Ivan Valiela and Elizabeth Elmstrom were supported by Woods Hole Sea Grant, NOAA grant no. NA14OAR4170074. Javier Lloret was supported by a Rosenthal Postdoctoral Fellowship Award from the Marine Biological Laboratory, and by a Northeast Climate Science Center Fellowship. Tynan Bowyer was supported by a Metcalf Research Fellowship of the University of Chicago. David Remsen was supported by MBL Cox and Bernstein funds.2020-06-0